摘要：
Constructing non-noble metal-based electrocatalysts supported on heteroatom-doped porous carbon materials with robust and enduring electrocatalytic activities for the oxygen reduction/evolution reactions (ORR/OER) is essential for propelling advancements in energy-related technologies. In this study, Co 2 P nanoparticles and Fe-N x sites embedded N, P co-doped micro-/meso-/macroporous graphitized carbon nanosheets (Co 2 P/Fe-N x @NPC) catalyst was designed via an eco-friendly phytic acid (PA)-assisted phosphidation strategy. Its synthesis involved PA-etching two-dimensional Core@shell leaf-like zeolitic imidazolium frameworks (Fe-ZIF-L@Zn/Co-ZIF-L) precursor and pyrolysis. PA not only acts as an etching agent but also is a phosphorus source for the formation of P-doping and Co 2 P. The leaf-like core-shell morphology, high surface area and excellent pore structure of graphitized carbon nanosheets facilitated the surface electron transfer and the diffusion of reactive species. Notably, the resulting Co 2 P/Fe-N x @NPC catalyst exhibited remarkable activity in both ORR (E 1/2 = 0.835 V) and OER (η 10 = 0.310 V). The theoretical investigations reveal that the synergistic effect of Fe-N 4 sites and Co 2 P nanoparticles optimized ORR intermediates adsorption and accelerated the reaction kinetics. Moreover, its bifunctional activity parameter (ΔE) for ORR and OER was only 0.705 V, which was lower than Pt/C+RuO 2 catalyst (0.715 V). This study demonstrates an effective strategy to develop ZIF-L-derived catalysts with good morphology and dual active sites.
Constructing non-noble metal-based electrocatalysts supported on heteroatom-doped porous carbon materials with robust and enduring electrocatalytic activities for the oxygen reduction/evolution reactions (ORR/OER) is essential for propelling advancements in energy-related technologies. In this study, Co 2 P nanoparticles and Fe-N x sites embedded N, P co-doped micro-/meso-/macroporous graphitized carbon nanosheets (Co 2 P/Fe-N x @NPC) catalyst was designed via an eco-friendly phytic acid (PA)-assisted phosphidation strategy. Its synthesis involved PA-etching two-dimensional Core@shell leaf-like zeolitic imidazolium frameworks (Fe-ZIF-L@Zn/Co-ZIF-L) precursor and pyrolysis. PA not only acts as an etching agent but also is a phosphorus source for the formation of P-doping and Co 2 P. The leaf-like core-shell morphology, high surface area and excellent pore structure of graphitized carbon nanosheets facilitated the surface electron transfer and the diffusion of reactive species. Notably, the resulting Co 2 P/Fe-N x @NPC catalyst exhibited remarkable activity in both ORR (E 1/2 = 0.835 V) and OER (η 10 = 0.310 V). The theoretical investigations reveal that the synergistic effect of Fe-N 4 sites and Co 2 P nanoparticles optimized ORR intermediates adsorption and accelerated the reaction kinetics. Moreover, its bifunctional activity parameter (ΔE) for ORR and OER was only 0.705 V, which was lower than Pt/C+RuO 2 catalyst (0.715 V). This study demonstrates an effective strategy to develop ZIF-L-derived catalysts with good morphology and dual active sites.
摘要：
Although it has been demonstrated that biochar is an efficient technique for alleviating phosphate pollution in water, its widespread application has been limited due to the low adsorption capacity of raw biochar. Given calcium's high affinity for phosphate, this study prepared biochar through the pyrolysis of waste crayfish shells (PC) in the presence of boric acid (donated as BPC) and investigated its performance in removing phosphate from water. The experimental results shown that boric acid improved phosphate removal percentage of PC from 30.1% to 99.2% via enhancing the specific surface area and decreasing the original phosphorus content. The phosphate adsorption process of BPC followed a pseudo-first-order kinetic model, and the maximum adsorption capacity was 12.14 mg g -1 . The Langmuir equation could better describe its adsorption behavior. Additionally, BPC exhibited excellent phosphate adsorption performance in a wide pH range, and high tolerance to co-existing ions in water. This study provided a promising method to enhance the performance of PC, benefitting the wide application of PC.
Although it has been demonstrated that biochar is an efficient technique for alleviating phosphate pollution in water, its widespread application has been limited due to the low adsorption capacity of raw biochar. Given calcium's high affinity for phosphate, this study prepared biochar through the pyrolysis of waste crayfish shells (PC) in the presence of boric acid (donated as BPC) and investigated its performance in removing phosphate from water. The experimental results shown that boric acid improved phosphate removal percentage of PC from 30.1% to 99.2% via enhancing the specific surface area and decreasing the original phosphorus content. The phosphate adsorption process of BPC followed a pseudo-first-order kinetic model, and the maximum adsorption capacity was 12.14 mg g -1 . The Langmuir equation could better describe its adsorption behavior. Additionally, BPC exhibited excellent phosphate adsorption performance in a wide pH range, and high tolerance to co-existing ions in water. This study provided a promising method to enhance the performance of PC, benefitting the wide application of PC.
摘要：
Despite extensive studies on dibutyl phthalate (DBP) degradation in isolated bacterial cultures, the primary degraders, community dynamics, and metabolic pathways involved in its biotransformation within complex sediment microbial communities remain poorly understood. In this study, we aimed to investigate the biotransformation mechanism of DBP by microorganisms in a sediment–water system by employing gas chromatography-mass spectrometry, 16S rRNA gene sequencing, metagenomic analysis, and bacterial isolation techniques. We observed that DBP biotransformation has three distinct phases: lag, degradative, and stationary. During the degradative phase, DBP gets progressively degraded by microorganisms, resulting in a microbial community with reduced stability and ambiguous boundaries. DBP, primarily metabolised by key phylotypes into monobutyl phthalate (MBP), phthalic acid (PA), and protocatechuic acid, subsequently enters the tricarboxylic acid (TCA) cycle. Through metagenomic analysis, ten functional genes from five genera were identified as crucial for DBP metabolism. Firstly, Arthrobacter degrades DBP into MBP and PA using pheA. Subsequently, Acinetobacter , Massilia, and Arthrobacter convert PA into TCA cycle intermediates using phtBAaAbAcAd and pcaCH. Concurrently, Hydrogenophaga and Acidovorax degrade PA to TCA cycle intermediates through pht1234 and ligAB. Genes related to amino acid synthesis, ABC transporters, and two-component regulatory systems also contribute significantly. Thus, the listed key bacteria, along with their diverse functional genes, collectively exhibit a high capacity for DBP degradation. This study provides insights into the bacterial responses to DBP degradation and offers a theoretical basis for the prevention and control of this pollutant.
Despite extensive studies on dibutyl phthalate (DBP) degradation in isolated bacterial cultures, the primary degraders, community dynamics, and metabolic pathways involved in its biotransformation within complex sediment microbial communities remain poorly understood. In this study, we aimed to investigate the biotransformation mechanism of DBP by microorganisms in a sediment–water system by employing gas chromatography-mass spectrometry, 16S rRNA gene sequencing, metagenomic analysis, and bacterial isolation techniques. We observed that DBP biotransformation has three distinct phases: lag, degradative, and stationary. During the degradative phase, DBP gets progressively degraded by microorganisms, resulting in a microbial community with reduced stability and ambiguous boundaries. DBP, primarily metabolised by key phylotypes into monobutyl phthalate (MBP), phthalic acid (PA), and protocatechuic acid, subsequently enters the tricarboxylic acid (TCA) cycle. Through metagenomic analysis, ten functional genes from five genera were identified as crucial for DBP metabolism. Firstly, Arthrobacter degrades DBP into MBP and PA using pheA. Subsequently, Acinetobacter , Massilia, and Arthrobacter convert PA into TCA cycle intermediates using phtBAaAbAcAd and pcaCH. Concurrently, Hydrogenophaga and Acidovorax degrade PA to TCA cycle intermediates through pht1234 and ligAB. Genes related to amino acid synthesis, ABC transporters, and two-component regulatory systems also contribute significantly. Thus, the listed key bacteria, along with their diverse functional genes, collectively exhibit a high capacity for DBP degradation. This study provides insights into the bacterial responses to DBP degradation and offers a theoretical basis for the prevention and control of this pollutant.
关键词：
Micropore-adjusted gas diffusion electrode;Electro-chemical process;Oxygen reduction;Filler;Electro-Fenton
摘要：
A micropore-adjusted gas diffusion electrode (MAGDE) is prepared using CBCNT (Mixture of carbon black and carbon nanotubes), polytetrafluorethylene (PTFE), wood pulp and filler. Meantime, an in-situ electrosynthesis process of hydrogen peroxide is constructed by a MAGDE cathode and a carbon felt anode. The results show that when the optimal mass ratio of PTFE:pulp:filler:CBCNT is 1.5:0.15:3:1, H2O2 yield can reach to 99.8 mg/(L.cm2) in 90 min. Under the optimal parameters of 60 mA/cm2 and pH of 3, H2O2 yield can reach to 114.4 mg/(L.cm2). For 20 mA/cm2, current utilization efficiency and energy consumption are 76.5 % and 8.6 KWh/kg in 30 min, respectively. A series of tests show that when filler is added, surface porous characteristics, electroactive surface and oxygen transfer ability are all improved and possible mechanisms on H2O2 yield increment are suggested. H2O2 yield and wastewater treatment show that the prepared MAGDE is effective and the preparation process is feasible.
A micropore-adjusted gas diffusion electrode (MAGDE) is prepared using CBCNT (Mixture of carbon black and carbon nanotubes), polytetrafluorethylene (PTFE), wood pulp and filler. Meantime, an in-situ electrosynthesis process of hydrogen peroxide is constructed by a MAGDE cathode and a carbon felt anode. The results show that when the optimal mass ratio of PTFE:pulp:filler:CBCNT is 1.5:0.15:3:1, H2O2 yield can reach to 99.8 mg/(L.cm2) in 90 min. Under the optimal parameters of 60 mA/cm2 and pH of 3, H2O2 yield can reach to 114.4 mg/(L.cm2). For 20 mA/cm2, current utilization efficiency and energy consumption are 76.5 % and 8.6 KWh/kg in 30 min, respectively. A series of tests show that when filler is added, surface porous characteristics, electroactive surface and oxygen transfer ability are all improved and possible mechanisms on H2O2 yield increment are suggested. H2O2 yield and wastewater treatment show that the prepared MAGDE is effective and the preparation process is feasible.
期刊：
Materials Research Bulletin,2025年:113708 ISSN：0025-5408
通讯作者：
Fengjiao Quan<&wdkj&>Zhiping Yang<&wdkj&>Jianfen Li
作者机构：
[Fengjiao Quan; Xiaolan Chen; Wenjuan Shen; Jianfen Li; Fangyuan Chen] College of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, P. R. China;[Zhiping Yang] School of Materials and Environmental Engineering, Chengdu Technological University, Chengdu 610031, China
通讯机构：
[Fengjiao Quan; Jianfen Li] C;[Zhiping Yang] S;School of Materials and Environmental Engineering, Chengdu Technological University, Chengdu 610031, China<&wdkj&>College of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, P. R. China
摘要：
Photocatalytic degradation is a promising approach for tackling insecticide pollution, such as imidacloprid (IMI), but it faces challenges including low efficiency, long treatment times, and limited mineralization. Herein, we report a method utilizing carboxymethyl cellulose (CMC) macromolecules to regulate the growth of bismuth oxychloride (BiOCl) and synthesize ultra-thin BiOCl nanosheets (UT- BiOCl) for the photocatalytic removal of IMI. UT-BiOCl can photocatalytically degrade 99.9% of IMI within 80 minutes. The photocatalytic degradation rate of IMI by UT- BiOCl was 2.4 times that of BiOCl. Moreover, the photocatalytic degradation of IMI by UT- BiOCl was still as high as 90% after 5 cycles. Further experiments and density functional theory (DFT) show that the regulation of CMC not only significantly improves the separation and transfer efficiency of photogenerated electrons and holes, but also promotes the generation of reactive species. As a result, the photocatalytic performance of the UT- BiOCl was substantially improved. This study offers a feasible strategy for the biomass-assisted synthesis of highly efficient photocatalysts.
Photocatalytic degradation is a promising approach for tackling insecticide pollution, such as imidacloprid (IMI), but it faces challenges including low efficiency, long treatment times, and limited mineralization. Herein, we report a method utilizing carboxymethyl cellulose (CMC) macromolecules to regulate the growth of bismuth oxychloride (BiOCl) and synthesize ultra-thin BiOCl nanosheets (UT- BiOCl) for the photocatalytic removal of IMI. UT-BiOCl can photocatalytically degrade 99.9% of IMI within 80 minutes. The photocatalytic degradation rate of IMI by UT- BiOCl was 2.4 times that of BiOCl. Moreover, the photocatalytic degradation of IMI by UT- BiOCl was still as high as 90% after 5 cycles. Further experiments and density functional theory (DFT) show that the regulation of CMC not only significantly improves the separation and transfer efficiency of photogenerated electrons and holes, but also promotes the generation of reactive species. As a result, the photocatalytic performance of the UT- BiOCl was substantially improved. This study offers a feasible strategy for the biomass-assisted synthesis of highly efficient photocatalysts.
期刊：
Journal of Industrial and Engineering Chemistry,2025年 ISSN：1226-086X
通讯作者：
Fengjiao Quan<&wdkj&>Xiufan Liu<&wdkj&>Jianfen Li
作者机构：
[Fengjiao Quan; Pengfei Xu; Wenjuan Shen; Yuhao Li; Jianfen Li; Yun He; Fangyuan Chen] College of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, PR China;[Xiufan Liu] Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi 435002, PR China
通讯机构：
[Fengjiao Quan; Jianfen Li] C;[Xiufan Liu] H;Hubei Key Laboratory of Pollutant Analysis and Reuse Technology, College of Chemistry and Chemical Engineering, Hubei Normal University, Huangshi 435002, PR China<&wdkj&>College of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, PR China
摘要：
Nitrate (NO 3 − ) pollution in groundwater has emerged as a pressing environmental issue of global concern. The excessive application of chemical fertilizers is widely recognized as the primary contributor to this pollution Nitrate ions pose significant risks to human health and the ecological environment. Electrochemical reduction of NO 3 − to NH 3 (NITRR) represents an effective approach for nitrogen recovery and recycling. Among many electrode materials, copper-based catalysts were considered promising due to their low cost and strong NO 3 − conversion capability. However, excessively strong adsorption can lead to catalyst deactivation, thereby diminishing catalytic activity. In this study, we developed an electrode material (Cu@NiO/NF) with low-valent copper (Cu δ+ ) through the combination of Cu and NiO, and it exhibited excellent catalytic performance in the NITRR process. At − 0.45 V vs. RHE, this catalyst achieved a Faraday efficiency of 95.7 % and an ammonia yield of 0.85 mg h −1 cm −2 . Further experiments and theoretical calculations demonstrate that the presence of NiO in Cu@NiO/NF stabilizes Cu δ+ , thereby enhancing the charge transfer rate and promoting the formation of hydrogen radicals (H•). This work has pioneered a new avenue for the development of efficient and innovative NTIRR materials.
Nitrate (NO 3 − ) pollution in groundwater has emerged as a pressing environmental issue of global concern. The excessive application of chemical fertilizers is widely recognized as the primary contributor to this pollution Nitrate ions pose significant risks to human health and the ecological environment. Electrochemical reduction of NO 3 − to NH 3 (NITRR) represents an effective approach for nitrogen recovery and recycling. Among many electrode materials, copper-based catalysts were considered promising due to their low cost and strong NO 3 − conversion capability. However, excessively strong adsorption can lead to catalyst deactivation, thereby diminishing catalytic activity. In this study, we developed an electrode material (Cu@NiO/NF) with low-valent copper (Cu δ+ ) through the combination of Cu and NiO, and it exhibited excellent catalytic performance in the NITRR process. At − 0.45 V vs. RHE, this catalyst achieved a Faraday efficiency of 95.7 % and an ammonia yield of 0.85 mg h −1 cm −2 . Further experiments and theoretical calculations demonstrate that the presence of NiO in Cu@NiO/NF stabilizes Cu δ+ , thereby enhancing the charge transfer rate and promoting the formation of hydrogen radicals (H•). This work has pioneered a new avenue for the development of efficient and innovative NTIRR materials.
摘要：
Developing efficient and stable bismuth-based photoelectrodes is one of the key points for producing green hydrogen in photocatalytic fuel cell (PFC). In this study, a PFC system with two photoelectrodes (a MoS 2 /Bi 2 S 3 /Bi 2 WO 6 photoanode and a MoS 2 -Ni foam photocathode) was established for the first time. The ternary Bi 2 WO 6 -based composite photoanode was characterized as having not only the broad visible absorption region but also strong interactions between Bi 2 WO 6 , Bi 2 S 3 and MoS 2 . Additionally, the ternary composite photoanode exhibits excellent photoelectrochemical performance, achieving a photocurrent density reaches 3.2 mA/cm 2 , which is 17.78 times that of pure Bi 2 WO 6 . These observations can be explained by the creation of a type II/Z-scheme heterostructure of MoS 2 /Bi 2 S 3 /Bi 2 WO 6 photoanode. The Density Functional Theory (DFT) simulation proves the formation of Z-scheme heterojunction between MoS 2 and Bi 2 S 3 , which offers an opportunity for facilitating the mitigation and separation of photoexcited charge. The dual-photoelectrode PFC system demonstrated an effective hydrogen production capacity, exhibiting an output of 18.32 μmol/cm 2 /h. At the same time, the power density was 0.1325 mW/cm 2 , exhibiting a 1.41-fold increase relative to the MoS 2 /Bi 2 S 3 /Bi 2 WO 6 -Pt PFC system. This work offers a novel method for building effective PFC systems that co-produce electricity and hydrogen.
Developing efficient and stable bismuth-based photoelectrodes is one of the key points for producing green hydrogen in photocatalytic fuel cell (PFC). In this study, a PFC system with two photoelectrodes (a MoS 2 /Bi 2 S 3 /Bi 2 WO 6 photoanode and a MoS 2 -Ni foam photocathode) was established for the first time. The ternary Bi 2 WO 6 -based composite photoanode was characterized as having not only the broad visible absorption region but also strong interactions between Bi 2 WO 6 , Bi 2 S 3 and MoS 2 . Additionally, the ternary composite photoanode exhibits excellent photoelectrochemical performance, achieving a photocurrent density reaches 3.2 mA/cm 2 , which is 17.78 times that of pure Bi 2 WO 6 . These observations can be explained by the creation of a type II/Z-scheme heterostructure of MoS 2 /Bi 2 S 3 /Bi 2 WO 6 photoanode. The Density Functional Theory (DFT) simulation proves the formation of Z-scheme heterojunction between MoS 2 and Bi 2 S 3 , which offers an opportunity for facilitating the mitigation and separation of photoexcited charge. The dual-photoelectrode PFC system demonstrated an effective hydrogen production capacity, exhibiting an output of 18.32 μmol/cm 2 /h. At the same time, the power density was 0.1325 mW/cm 2 , exhibiting a 1.41-fold increase relative to the MoS 2 /Bi 2 S 3 /Bi 2 WO 6 -Pt PFC system. This work offers a novel method for building effective PFC systems that co-produce electricity and hydrogen.
摘要：
This study aimed to enhance nickel-based catalysts for biomass pyrolysis to produce syngas. Two types of catalysts, composite (Ni/Zn-Zr-BC) and metal (Ni/Zn–Zr) supports, were developed via the sol-gel method. The catalysts' morphology and composition changes were analyzed using XRD, SEM, BET, and TPR. The performance of the biomass carbon-doped catalysts was compared to their non-doped counterparts. The biomass carbon-doped catalysts exhibited a significant 42% increase in hydrogen yield compared to non-doped counterparts. At temperatures above 800 °C, the optimal gas yield reached 0.71 L/g at 900 °C with a 20-min residence time and a biomass carbon ratio of 0.75, demonstrating robust catalyst stability. The performance improvement is attributed to biochar's antioxidative capability, which preserves active metal sites and reduces oxidation states, enhancing reaction efficiency.
This study aimed to enhance nickel-based catalysts for biomass pyrolysis to produce syngas. Two types of catalysts, composite (Ni/Zn-Zr-BC) and metal (Ni/Zn–Zr) supports, were developed via the sol-gel method. The catalysts' morphology and composition changes were analyzed using XRD, SEM, BET, and TPR. The performance of the biomass carbon-doped catalysts was compared to their non-doped counterparts. The biomass carbon-doped catalysts exhibited a significant 42% increase in hydrogen yield compared to non-doped counterparts. At temperatures above 800 °C, the optimal gas yield reached 0.71 L/g at 900 °C with a 20-min residence time and a biomass carbon ratio of 0.75, demonstrating robust catalyst stability. The performance improvement is attributed to biochar's antioxidative capability, which preserves active metal sites and reduces oxidation states, enhancing reaction efficiency.
摘要：
A novel pocket-shaped air-breathing electrode (PSABE) is prepared using carbon material (CM), polytetrafluorethylene (PTFE), pulp and filler. Additionally, an in-situ electro-synthesis of H 2 O 2 is constructed using the PSABE and the carbon felt. The results show that under current density of 50 mA/cm 2 and solution pH of 3, compared with classical gas diffusion electrode and micropore-adjusted gas diffusion electrode, the PSABE's H 2 O 2 yield is the highest and 110.1 mg/(L.cm 2 ) in 90 min, and its oxygen diffusion coefficient is also the highest and 1.68 × 10 −5 m 2 /s. When the optimal mass ratio of PTFE:filler in the electrode wall:filler in the electrode pocket:CM is 1.5:3:3:1, the PSABE's H 2 O 2 yield further climbs to 112.0 mg/(L.cm 2 ). A series of detections show that when filler in the electrode wall increases, the PSABE's pore structure is more abundant, active sites are more and oxygen diffusion capability becomes better. Similarly, when filler in the electrode pocket increases, air mobility inside and outside the cavity goes easier and the PSABE oxygen diffusion capability improves, too. Additionally, when current density varies from 20 to 70 mA/cm 2 , H 2 O 2 yield for 70 mA/cm 2 can attain to 143.4 mg/(L.cm 2 ) while current efficiency and energy consumption for 20 mA/cm 2 is 84.9% and 8.4 KWh/kg, respectively. Moreover, results of H 2 O 2 yield, disinfection and wastewater treatment show that the prepared PSABE is effective and feasible.
A novel pocket-shaped air-breathing electrode (PSABE) is prepared using carbon material (CM), polytetrafluorethylene (PTFE), pulp and filler. Additionally, an in-situ electro-synthesis of H 2 O 2 is constructed using the PSABE and the carbon felt. The results show that under current density of 50 mA/cm 2 and solution pH of 3, compared with classical gas diffusion electrode and micropore-adjusted gas diffusion electrode, the PSABE's H 2 O 2 yield is the highest and 110.1 mg/(L.cm 2 ) in 90 min, and its oxygen diffusion coefficient is also the highest and 1.68 × 10 −5 m 2 /s. When the optimal mass ratio of PTFE:filler in the electrode wall:filler in the electrode pocket:CM is 1.5:3:3:1, the PSABE's H 2 O 2 yield further climbs to 112.0 mg/(L.cm 2 ). A series of detections show that when filler in the electrode wall increases, the PSABE's pore structure is more abundant, active sites are more and oxygen diffusion capability becomes better. Similarly, when filler in the electrode pocket increases, air mobility inside and outside the cavity goes easier and the PSABE oxygen diffusion capability improves, too. Additionally, when current density varies from 20 to 70 mA/cm 2 , H 2 O 2 yield for 70 mA/cm 2 can attain to 143.4 mg/(L.cm 2 ) while current efficiency and energy consumption for 20 mA/cm 2 is 84.9% and 8.4 KWh/kg, respectively. Moreover, results of H 2 O 2 yield, disinfection and wastewater treatment show that the prepared PSABE is effective and feasible.
摘要：
Ammonia (NH 3 ), a widely used chemical product, has various applications in numerous fields. However, the high energy consumption of the traditional ammonia synthesis process is inconsistent with the pursuit of “zero carbon,” and there is an urgent need for a new method to synthesize NH 3 . The electrocatalytic NO 3 − -to-NH 3 (NITRR) offers an ideal route to synthesizing NH 3 under ambient conditions. Nano zero-valent iron (nZVI) has been widely used in nitrate wastewater treatment due to its environmental friendliness, low cost, and high activity. However, nZVI is difficult to recover and prone to deactivation because of its tendency to corrode and agglomerate. Here, we report a method to enhance the activity and stability of nZVI through oxalic acid modification. In this study, oxalic acid and citric acid modified nZVI on foam nickel substrates (OA-nZVI/NF) was examined as examples. Experiments confirmed that the Faraday efficiency of NH 3 (FE NH3 ) from OA-nZVI/NF was 84.9 %, respectively, at −0.4 V vs. RHE, which was significantly higher than that of nZVI/NF (64.5 %). More importantly, the FE NH3 of OA-nZVI/NF electrod did not decrease significantly after continuous electrolysis for 100 h. Subsequently, electrochemical characterization and control experiments revealed that oxalic acid modification reduced the corrosion potential of nZVI/NF and promoted the generation of hydrogen-free radicals (H*) from nZVI/NF. This work provides an economical and feasible approach to improving the stability and activity of corrosion-prone and deactivated materials.
Ammonia (NH 3 ), a widely used chemical product, has various applications in numerous fields. However, the high energy consumption of the traditional ammonia synthesis process is inconsistent with the pursuit of “zero carbon,” and there is an urgent need for a new method to synthesize NH 3 . The electrocatalytic NO 3 − -to-NH 3 (NITRR) offers an ideal route to synthesizing NH 3 under ambient conditions. Nano zero-valent iron (nZVI) has been widely used in nitrate wastewater treatment due to its environmental friendliness, low cost, and high activity. However, nZVI is difficult to recover and prone to deactivation because of its tendency to corrode and agglomerate. Here, we report a method to enhance the activity and stability of nZVI through oxalic acid modification. In this study, oxalic acid and citric acid modified nZVI on foam nickel substrates (OA-nZVI/NF) was examined as examples. Experiments confirmed that the Faraday efficiency of NH 3 (FE NH3 ) from OA-nZVI/NF was 84.9 %, respectively, at −0.4 V vs. RHE, which was significantly higher than that of nZVI/NF (64.5 %). More importantly, the FE NH3 of OA-nZVI/NF electrod did not decrease significantly after continuous electrolysis for 100 h. Subsequently, electrochemical characterization and control experiments revealed that oxalic acid modification reduced the corrosion potential of nZVI/NF and promoted the generation of hydrogen-free radicals (H*) from nZVI/NF. This work provides an economical and feasible approach to improving the stability and activity of corrosion-prone and deactivated materials.
摘要：
Thermochemical conversion of agricultural by-products into hydrogen-rich syngas is a technology that offers both economic and environmental benefits. In this work, we investigated a biochar-supported nickel-based catalyst for the catalytic pyrolysis of straw biomass to produce hydrogen-rich syngas. The by-product, straw biochar, was used as a material for synthesizing fresh catalysts, achieving a closed-loop process. We explored gas yields under various conditions. The highest yields of CO and H2, reaching 0.52 L/g and 0.48 L/g, respectively, were obtained under the conditions of a pyrolysis temperature of 900 degrees C, a residence time of 20 min, a calcination temperature of 400 degrees C, a nickel loading of 15 wt%, and a citric acid to potassium hydroxide ratio of 1:4. The catalysts were characterized using XRD, H2-TPR, SEM, and TEM. The results demonstrated that biochar provides excellent support and synergy, enabling the catalyst to function at high temperatures and offering antioxidative protection to the active metals during the thermal process. Overall, this catalytic pyrolysis process, aiming for green and efficient conversion, achieved high yields of syngas and hydrogen.
作者机构：
[Zhang, Junjie; Song, Hao; Yang, Haiping; Chen, Hanping; Shao, Jingai; Yu, Jie; Jiang, Hao; Fan, Tingting] Huazhong Univ Sci & Technol, Sch Energy & Power Engn, State Key Lab Coal Combust, Wuhan 430074, Hubei Province, Peoples R China.;[Zhang, Junjie; Chen, Hanping; Shao, Jingai; Jiang, Hao; Fan, Tingting] Huazhong Univ Sci & Technol, Sch Energy & Power Engn, Dept New Energy Sci & Engn, Wuhan 430074, Hubei Province, Peoples R China.;[Li, Jianfen] Wuhan Polytech Univ, Sch Chem & Environm Engn, Wuhan 430023, Hubei, Peoples R China.;[Agblevor, Foster] Utah State Univ, USTAR Bioenergy Ctr, Dept Biol Engn, Logan, UT 84341 USA.;[Zhang, Junjie; Shao, Jingai; Zhang, JJ; Shao, JA] 1037 Luoyu Rd, Wuhan 430074, Hubei, Peoples R China.
通讯机构：
[Zhang, JJ; Shao, JA ] 1;1037 Luoyu Rd, Wuhan 430074, Hubei, Peoples R China.
关键词：
Metal oxide;Molecular dynamics simulation;Monoaromatic hydrocarbons;Volatile desulfurization;Waste tire pyrolysis
摘要：
Pyrolysis can effectively convert waste tires into high-value products. However, the sulfur-containing compounds in pyrolysis oil and gas would significantly reduce the environmental and economic feasibility of this technology. Here, the desulfurization and upgrade of waste tire pyrolysis oil and gas were performed by adding different metal oxides (Fe(2)O(3), CuO, and CaO). Results showed that Fe(2)O(3) exhibited the highest removal efficiency of 87.7% for the sulfur-containing gas at 600°C with an outstanding removal efficiency of 99.5% for H(2)S. CuO and CaO were slightly inferior to Fe(2)O(3), with desulfurization efficiencies of 75.9% and 45.2% in the gas when added at 5%. Fe(2)O(3) also demonstrated a notable efficacy in eliminating benzothiophene, the most abundant sulfur compound in pyrolysis oil, with a removal efficiency of 78.1%. Molecular dynamics simulations and experiments showed that the desulfurization mechanism of Fe(2)O(3) involved the bonding of Fe-S, the breakage of C-S, dehydrogenation and oxygen migration process, which promoted the conversion of Fe(2)O(3) to FeO, FeS and Fe(2)(SO(4))(3). Meanwhile, Fe(2)O(3) enhanced the cyclization and dehydrogenation reaction, facilitating the upgrade of oil and gas (monocyclic aromatics to 57.4% and H(2) to 22.3%). This study may be helpful for the clean and high-value conversion of waste tires.
摘要：
This work reports a novel TiO2/g-C3N4 photoanode-based photocatalytic fuel cell (PFC) designed to convert chemical energy from simulated wastewater. The g-C3N4 modified TiO2 nanorod was successfully synthesized by a facile hydrothermal method. The results indicated that the maximum photocurrent density reached 2.44 mA cm-2 at 1.23 V vs. RHE by 1.167 g L-1 g-C3N4 loaded TiO2 composite. On the basis of analysis, the photoelectrochemical mechanism of the composite photoanode was proposed. This mainly demonstrated that the composite photoanode increases the electron donor density and boosts charge separation efficiency. In addition, the power density and hydrogen production of the proposed PFC were enhanced by 5.37 and 1.49 times compared to TiO2 photoanode-based PFC. To find the origins of the excellent performance of PFC, the influence of the organic compounds were investigated. The ESR measurement results indicated that the organic matter was captured by the photoexcited holes directly to facilitate the charge separation. The achieved power density and hydrogen production of 0.14 mW cm-2 and 21.60 mu mol h-1 cm-2 were measured using RhB as the model pollutant, which was 2.42 and 1.23 times higher than the experiments with PBS electrolyte. This study proposed a novel PFC system converts the organic pollutant to the hydrogen and the electricity.
摘要：
Chemical looping is a promising technology for hydrogen production. Achieving both high purity and yield is an ongoing challenge, due to low fuel conversion and carbon deposition. In this study, a sorption-enhanced chemical looping reforming coupled with water splitting (SE-CLSR-WS) process was proposed to co-produce syngas and H 2 by using waste plastic as the fuel. The Ni-doped Ca 2 Fe 2 O 5 brownmillerites were designed and employed as oxygen carriers (OCs) and CO 2 sorbent. The introduction of Ni leaded to lattice distortion of brownmillerite, thereby enhancing the redox activity of lattice oxygen. In fuel reactor (FR), CaO in-situ captured CO 2 and shifted reaction equilibrium towards PET pyrolysis gas reforming, enhancing both syngas yield and PET conversion rates. Adhere to the surface of OCs, CaO improved cyclic performance by inhibiting agglomeration of active metals. Calcination reactor (CR) was set between FR and steam rector (SR) to in-situ desorb CO 2 and remove carbon deposition, enhancing hydrogen purity in SR. When Ca 2 Ni 0.75 Fe 1.25 O 5 -0.25CaO was applied to SE-CLSR-WS process, it exhibited synergistically strengthened performance in reaction activity, sorption capacity and cyclic stability, with a syngas purity of 82.71 % and H 2 yield of 8.01 mmol/g OC with 93.26 % purity.
通讯机构：
[Peng, X ] C;[Quan, FJ ] W;Wuhan Polytech Univ, Sch Chem & Environm Engn, Wuhan 430023, Peoples R China.;Cent China Normal Univ, Inst Environm & Appl Chem, Minist Educ, Key Lab Pesticide & Chem Biol, Wuhan 430079, Peoples R China.
摘要：
Recently, researchers have been paying much attention to zero-valent iron (ZVI) in the field of pollution remediation. However, the depressed electron transport from the iron reservoir to the iron oxide shell limited the wide application of ZVI. This study was aimed at promoting the performance of microscale ZVI (mZVI) for hexavalent chromium (Cr( VI )) removal by accelerating iron cycle with the addition of boron powder. It was found that the addition of boron powder enhanced the Cr( VI ) removal rate by 2.1 times, and the proportion of Cr( III ) generation after Cr( VI ) removal process also increased, suggesting that boron could promote the reduction pathway of Cr( VI ) to Cr( III ). By further comparing the Cr( VI ) removal percentage of Fe( III ) with or without the boron powder, we found that boron powder could promote the percentage removal of Cr( VI ) with Fe( III ) from 10.1% to 33.6%. Moreover, the presence of boron powder could decrease the potential gap values (Δ E p ) between Fe( III ) reduction and Fe( II ) oxidation from 0.668 V to 0.556 V, further indicating that the added boron powder could act as an electron sacrificial agent to promote the reduction process of Fe( III ) to Fe( II ), and thus enhancing the reduction of Cr( VI ) with Fe( II ). This study shed light on the promoted mechanism of Cr( VI ) removal with boron powder and provided an environmentally friendly and efficient approach to enhance the reactivity of the mZVI powder, which would benefit the wide application of mZVI technology in the environmental remediation field.
关键词：
TiO 2 electron transport layer;Two-dimensional MoS 2;Density functional theory;Photocatalytic fuel cell;Synergistic effect
摘要：
The poor contact between the photocatalyst and the FTO substrate are the main factors lead to the low performance of photocatalytic fuel cell (PFC). Herein, a FTO pre-treated with a TiO2 electron transport layer was used as a substrate for the synthesis of the MoS2/BiVO4/pre-FTO photoanode. The proposed MBV-4/pre-FTO photoanode with its enhances the visible light absorption and effectively delays the recombination of the photoexcited charge. The MBV-4/pre-FTO composite photoanode (6.02 mA/cm2) exhibited a photocurrent density that was 2.2 times higher than that of the BiVO4 photoanode (2.78 mA/cm2). This is attributed to the short charge migration length of the thin MoS2 layer, the fast photoexcited electron transport effect of the TiO2 seed layer, and the heterojunction structure of the proposed photoanode. The DFT calculation result indicated that the TiO2 electron transport layer showed an outstanding photoelectron attractive and transporting effect. The MoS2/Ni foam was employed as the photocathode to establish a mismatched Fermi level for driving PFC. The short-circuit current, open-circuit voltage, and maximum power density of the PFC were 0.578 mA/cm2, 0.632 V, and 0.125 mW/cm2, respectively. The main photodegradation active species are the superoxide anion (∙O2–) and the photoexcited hole (h+), and the degradation efficiency is 61.97 %.
The poor contact between the photocatalyst and the FTO substrate are the main factors lead to the low performance of photocatalytic fuel cell (PFC). Herein, a FTO pre-treated with a TiO2 electron transport layer was used as a substrate for the synthesis of the MoS2/BiVO4/pre-FTO photoanode. The proposed MBV-4/pre-FTO photoanode with its enhances the visible light absorption and effectively delays the recombination of the photoexcited charge. The MBV-4/pre-FTO composite photoanode (6.02 mA/cm2) exhibited a photocurrent density that was 2.2 times higher than that of the BiVO4 photoanode (2.78 mA/cm2). This is attributed to the short charge migration length of the thin MoS2 layer, the fast photoexcited electron transport effect of the TiO2 seed layer, and the heterojunction structure of the proposed photoanode. The DFT calculation result indicated that the TiO2 electron transport layer showed an outstanding photoelectron attractive and transporting effect. The MoS2/Ni foam was employed as the photocathode to establish a mismatched Fermi level for driving PFC. The short-circuit current, open-circuit voltage, and maximum power density of the PFC were 0.578 mA/cm2, 0.632 V, and 0.125 mW/cm2, respectively. The main photodegradation active species are the superoxide anion (∙O2–) and the photoexcited hole (h+), and the degradation efficiency is 61.97 %.
作者机构：
[Li, Jianfen; Cai, Yingying; Qin, Zhenhua; Li, Hui] School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan, 430023, PR China;[Deng, Huatang] National Agricultural Science Observing and Experimental Station of Chongqing, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Science, Wuhan, 430223, PR China;[Zhou, Yiyong; Cao, Xiuyun] Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, PR China;[Song, Chunlei] Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, PR China. Electronic address: clsong@ihb.ac.cn;[Duan, XinBin] National Agricultural Science Observing and Experimental Station of Chongqing, Yangtze River Fisheries Research Institute, Chinese Academy of Fishery Science, Wuhan, 430223, PR China. Electronic address: duan@yfi.ac.cn
通讯机构：
[Chunlei Song] I;Institute of Hydrobiology, Chinese Academy of Sciences, Wuhan, 430072, PR China
摘要：
In order to clarify the nitrogen (N) and phosphorus (P) regeneration patterns and internal mechanism for initiating and maintaining algal blooms in Lake Taihu, samples (including surface water and sediment) from 8 sites in Lake Taihu were collected for nine times from May 2010 to April 2011, and analyzed for total and labile organic matter, P fractionation and sorption behaviors, extracellular enzymatic activities (EEA), dehydrogenase activity, the respiratory electron transport system activity, and iron in sediment, EEA, N and P species and chlorophyll a (Chl. a) in surface water, as well as N and P species in interstitial water. In Lake Taihu, although severe blooms occurred in both Meiliang Bay and Zhushan Bay, the nutrient regeneration patterns stimulating the initiation and maintenance of algae blooms in these two bays were different. In Zhushan Bay with low EEA in surface water, abundant N and P flux from sediments, due to the degradation of organic matter and enzymatic hydrolysis in sediment, further stimulated the initiation and maintenance of algae blooms. In Meiliang Bay, in spite of lower nutrient supply from sediment, high EEA in surface water occurred later than the serious blooms, showing that the nutrient regeneration from sediment, not water body, was still the trigger for the start of the bloom, and sediment nutrient release and predominant surface water nutrient regeneration by abundant exoenzymes sustained the algal blooms. In the Western region, algal bloom started in the northern area and further spread in the remaining part of the lake; nutrient regeneration in the surface water sustained the slight bloom. In the East Bays, the decay and decomposition of macrophytes led to anaerobic conditions in sediments and high ammonia in interstitial water, but low iron bound phosphorus resulted in anaerobic release of very few P, thus showed extremely low Chl. a concentration.
In order to clarify the nitrogen (N) and phosphorus (P) regeneration patterns and internal mechanism for initiating and maintaining algal blooms in Lake Taihu, samples (including surface water and sediment) from 8 sites in Lake Taihu were collected for nine times from May 2010 to April 2011, and analyzed for total and labile organic matter, P fractionation and sorption behaviors, extracellular enzymatic activities (EEA), dehydrogenase activity, the respiratory electron transport system activity, and iron in sediment, EEA, N and P species and chlorophyll a (Chl. a) in surface water, as well as N and P species in interstitial water. In Lake Taihu, although severe blooms occurred in both Meiliang Bay and Zhushan Bay, the nutrient regeneration patterns stimulating the initiation and maintenance of algae blooms in these two bays were different. In Zhushan Bay with low EEA in surface water, abundant N and P flux from sediments, due to the degradation of organic matter and enzymatic hydrolysis in sediment, further stimulated the initiation and maintenance of algae blooms. In Meiliang Bay, in spite of lower nutrient supply from sediment, high EEA in surface water occurred later than the serious blooms, showing that the nutrient regeneration from sediment, not water body, was still the trigger for the start of the bloom, and sediment nutrient release and predominant surface water nutrient regeneration by abundant exoenzymes sustained the algal blooms. In the Western region, algal bloom started in the northern area and further spread in the remaining part of the lake; nutrient regeneration in the surface water sustained the slight bloom. In the East Bays, the decay and decomposition of macrophytes led to anaerobic conditions in sediments and high ammonia in interstitial water, but low iron bound phosphorus resulted in anaerobic release of very few P, thus showed extremely low Chl. a concentration.
摘要：
Ammonia (NH3) can be used as a fertilizer, a chemical or a new generation of fuel and has important agricultural and industrial value. Electrochemical NO3--to-NH3 (NITRR) can realize the conversion of waste into treasure and waste resources, which is a promising method for ammonia synthesis. However, the process of NITRR is very complicated, resulting in product diversification and poor selectivity. In this work, an iron modified cerium oxide in rod form (Fe/CeO2-rod) catalysts was designed and used for the NITRR. The Fe/CeO2-rod catalyst showed excellent activity, and achieves high Faradaic efficiency (FE 95%) and NH3 yield rate (4.04 mg h(-1) cm(-2)) in 0.1 M KOH electrolyte at - 0.52 V versus reversible hydrogen electrode. Furthermore, this catalyst exhibits a negligible activity decay during continuous electrolysis for 25 h. Further experiments provide the important role of Fe, which promote the formation of hydrogen radicals (H*). This study may provide new pathways to improve the activity of inexpensive catalysts for NITRR.
