摘要：
The deliberate introduction of oxygen vacancies (OVs) in semiconductor photocatalysts has emerged as an effective strategy for enhancing photocatalytic activity. However, the quantitative relationship between OV concentration and catalytic efficiency remains insufficiently understood. Herein, we developed a controlled hydrothermal synthesis of OV-engineered BiOBr nanosheets, employing ethylene glycol (EG) as a versatile structural modulator to precisely tailor OV concentrations. By systematically adjusting the EG/water ratio in the precursor solution, precise control over OV concentration was achieved. The optimized OV-enriched BiOBr photocatalyst exhibited dual functionality, showing a 2.5-fold increase in NO oxidation efficiency (from 20.7% to 51.8%) while significantly reducing the generation of toxic NO2 byproducts. Additionally, the material demonstrated exceptional antimicrobial activity, achieving over 98% inactivation of Escherichia coli (E. coli), a marked improvement compared to the 60% inactivation observed for the OV-deficient sample. Mechanistic studies, integrating reaction kinetics, in situ monitoring of reaction processes, reactive oxygen species (ROS) identification, and DFT calculation revealed that OV incorporation induces three synergistic effects: enhanced substrate adsorption, extended visible-light absorption, and optimized charge carrier dynamics. This study offers critical understanding of the function of OVs in photocatalysis and establishes a design framework for developing advanced photocatalytic materials for environmental and antimicrobial applications.
摘要：
Nitrogen-doped hierarchical meso/microporous carbons were successfully synthesized from tangerine peel through pyrolytic activation at elevated temperature in nitrogen atmosphere, utilizing potassium hydroxide as activator and melamine as nitrogen source. The resulting optimal hierarchical carbon (denoted as NBC-600) possessed a high specific surface area of 601.49 m 2 ·g −1 , along with a nitrogen doping level of 2.5 %, both of which contribute significantly to its outstanding supercapacitive performance. Electrochemical evaluations reveal that the NBC-600 electrode delivers an excellent gravimetric specific capacitance of 304.4 F·g −1 , accompanied by excellent cycling stability and rate capability. Moreover, a symmetric two-electrode supercapacitor assembled with NBC-600 achieves an energy density of 26.8 Wh·kg −1 at a corresponding power density of 250.0 W·kg −1 . Notably, the device demonstrates exceptional cycling stability, retaining 96.9 % of its initial capacitance after 10,000 charge-discharge cycles at a current density of 10 A·g −1 . The superior electrochemical properties of NBC-600 surpass that of numerous biomass-derived hierarchical porous carbons, underscoring its feasibility as a cost efficient and high-performance electrode material for next-generation supercapacitors.
Nitrogen-doped hierarchical meso/microporous carbons were successfully synthesized from tangerine peel through pyrolytic activation at elevated temperature in nitrogen atmosphere, utilizing potassium hydroxide as activator and melamine as nitrogen source. The resulting optimal hierarchical carbon (denoted as NBC-600) possessed a high specific surface area of 601.49 m 2 ·g −1 , along with a nitrogen doping level of 2.5 %, both of which contribute significantly to its outstanding supercapacitive performance. Electrochemical evaluations reveal that the NBC-600 electrode delivers an excellent gravimetric specific capacitance of 304.4 F·g −1 , accompanied by excellent cycling stability and rate capability. Moreover, a symmetric two-electrode supercapacitor assembled with NBC-600 achieves an energy density of 26.8 Wh·kg −1 at a corresponding power density of 250.0 W·kg −1 . Notably, the device demonstrates exceptional cycling stability, retaining 96.9 % of its initial capacitance after 10,000 charge-discharge cycles at a current density of 10 A·g −1 . The superior electrochemical properties of NBC-600 surpass that of numerous biomass-derived hierarchical porous carbons, underscoring its feasibility as a cost efficient and high-performance electrode material for next-generation supercapacitors.
摘要：
Self-supporting carbon fibers are extensively employed as active components in energy storage systems due to their tunable microstructures, large specific surface area, affordability, and excellent electrical conductivity. Nevertheless, conventional methods for producing carbon fibers typically involve complicated synthesis processes, environmental pollution, and high energy consumption. In this study, lignin-based carbon nanofibers (LCNFs) were prepared through electrospinning and subsequent heat treatment. The morphologies, crystal structures, and specific surface area of the as-prepared LCNFs were characterized using scanning electron microscopy, X-ray diffraction and nitrogen sorption isotherms. The influence of lignin content on the on the structural, morphological, and electrochemical properties of the carbon nanofibers were examined, particularly in their applications as supercapacitor and lithium-ion battery anode materials. The as-prepared LCNF-2 possess the highest specific surface area of 468.3 m2 g−1. As a self-supporting electrode in supercapacitors (SCs), the LCNF-2 delivered 256.3 F g−1 at 0.2 A g−1, and capacitance retention of 62.0 % at the current density raised from 0.5 to 10 A g−1. The assembled LCNF-2//LCNF-2 symmetric supercapacitor demonstrated a specific capacitance of 168 F g−1 at 5 A g−1, maintaining 100 % capacitance retention after 10,000 cycles. Additionally, it achieved an energy density of 5.6 Wh kg−1 at a power density of 1250.0 W kg−1. As a lithium-ion batteries (LIBs) anode, the LCNF-2 showed a discharge specific capacity of 1108.3 mAh g−1 and a discharge specific capacity of 377.3 mAh g−1 in the first cycle, with a capacity retention rate of 84.6 % after 100 cycles at 1C. This work offers a novel approach for the high-value utilization of agricultural waste straw lignin in energy storage devices.
Self-supporting carbon fibers are extensively employed as active components in energy storage systems due to their tunable microstructures, large specific surface area, affordability, and excellent electrical conductivity. Nevertheless, conventional methods for producing carbon fibers typically involve complicated synthesis processes, environmental pollution, and high energy consumption. In this study, lignin-based carbon nanofibers (LCNFs) were prepared through electrospinning and subsequent heat treatment. The morphologies, crystal structures, and specific surface area of the as-prepared LCNFs were characterized using scanning electron microscopy, X-ray diffraction and nitrogen sorption isotherms. The influence of lignin content on the on the structural, morphological, and electrochemical properties of the carbon nanofibers were examined, particularly in their applications as supercapacitor and lithium-ion battery anode materials. The as-prepared LCNF-2 possess the highest specific surface area of 468.3 m2 g−1. As a self-supporting electrode in supercapacitors (SCs), the LCNF-2 delivered 256.3 F g−1 at 0.2 A g−1, and capacitance retention of 62.0 % at the current density raised from 0.5 to 10 A g−1. The assembled LCNF-2//LCNF-2 symmetric supercapacitor demonstrated a specific capacitance of 168 F g−1 at 5 A g−1, maintaining 100 % capacitance retention after 10,000 cycles. Additionally, it achieved an energy density of 5.6 Wh kg−1 at a power density of 1250.0 W kg−1. As a lithium-ion batteries (LIBs) anode, the LCNF-2 showed a discharge specific capacity of 1108.3 mAh g−1 and a discharge specific capacity of 377.3 mAh g−1 in the first cycle, with a capacity retention rate of 84.6 % after 100 cycles at 1C. This work offers a novel approach for the high-value utilization of agricultural waste straw lignin in energy storage devices.
通讯机构：
[Chen, H ; Yang, Y; Zhang, XH] H;Huazhong Agr Univ, Coll Chem, Wuhan 430070, Peoples R China.
关键词：
Covalent organic frameworks;Photocatalytic H 2 production;Co coordination;Visible light;Highly efficient
摘要：
Covalent organic frameworks (COFs) have emerged as a crystalline porous materials for photocatalytic hydrogen production. However, the design of efficient COF-based catalyst for satisfactory solar-to-hydrogen energy conversion is still challenging. Here, cobalt was anchored on the bipyridine moieties in the framework of olefin-linked sp2c-COFdpy by convenient post-metalation (sp2c-COFdpy-Co). Experimental results showed that sp2c-COFdpy-Co exhibited wider visible light absorption region and quicker photogenerated e-/h+ separation efficiency than sp2c-COFdpy. Photocatalytic experiments revealed that sp2c-COFdpy-Co was highly efficient for H2 production after photodeposition of Pt co-catalyst (Pt@sp2c-COFdpy-Co). The optimized Pt@sp2c-COFdpy-Co exhibited a high photocatalytic H2 production rate of 324.4 μmol/h under visible light irradiation in the presence of 1.0 wt% Pt as co-catalyst, which was higher than Pt@sp2c-COFdpy-Fe and Pt@sp2c-COFdpy-Ni, and it was much higher than that of its counterparts and many reported works. This work provides new insights into design of highly efficient COF-based catalyst for photocatalytic H2 production.
Covalent organic frameworks (COFs) have emerged as a crystalline porous materials for photocatalytic hydrogen production. However, the design of efficient COF-based catalyst for satisfactory solar-to-hydrogen energy conversion is still challenging. Here, cobalt was anchored on the bipyridine moieties in the framework of olefin-linked sp2c-COFdpy by convenient post-metalation (sp2c-COFdpy-Co). Experimental results showed that sp2c-COFdpy-Co exhibited wider visible light absorption region and quicker photogenerated e-/h+ separation efficiency than sp2c-COFdpy. Photocatalytic experiments revealed that sp2c-COFdpy-Co was highly efficient for H2 production after photodeposition of Pt co-catalyst (Pt@sp2c-COFdpy-Co). The optimized Pt@sp2c-COFdpy-Co exhibited a high photocatalytic H2 production rate of 324.4 μmol/h under visible light irradiation in the presence of 1.0 wt% Pt as co-catalyst, which was higher than Pt@sp2c-COFdpy-Fe and Pt@sp2c-COFdpy-Ni, and it was much higher than that of its counterparts and many reported works. This work provides new insights into design of highly efficient COF-based catalyst for photocatalytic H2 production.
摘要：
Marine oil spills and the illegal discharge of industrial wastewater have resulted in significant environmental and ecological pollution. Consequently, it is essential to develop multifunctional oil-water separation materials that are abundant in raw materials, environmentally friendly, easily operable in complex environments, and fully recyclable. In this study, inspired by lotus leaves and mussels, a low-cost commercial polyurethane (PU) sponge was utilized as the substrate. Hydrophobic SiO₂ and magnetic Fe₃O₄ nanoparticles were modified by coating with self-polymerized dopamine to enhance surface roughness. The surface was chemically treated with fluorine-free, green, low-surface-energy polydimethylsiloxane (PDMS). Thus, a sponge exhibiting both superhydrophobic and superoleophilic properties was synthesized via impregnation technology. The results indicated that the modified PU sponge exhibited a water contact angle of 151.3°. The sponge demonstrated significant adsorption capacity for various oils and organic solvents, ranging from 20.55 to 33.63 times its own weight. The adsorption capacity remained stable after 10 separation cycles. Using gravity-driven flow or a peristaltic pump, the modified PU sponge achieved continuous oil-water separation with efficiency exceeding 97 %. The modified PU sponge demonstrated effective separation of toluene-in-water emulsions. It exhibited outstanding magnetic responsiveness, enabling rapid oil adsorption under magnetic guidance, and showed excellent flame retardancy to mitigate fire risks. This multifunctional polyurethane sponge, developed through synergistic modification, demonstrated significant potential for oil-water separation and environmental remediation applications.
Marine oil spills and the illegal discharge of industrial wastewater have resulted in significant environmental and ecological pollution. Consequently, it is essential to develop multifunctional oil-water separation materials that are abundant in raw materials, environmentally friendly, easily operable in complex environments, and fully recyclable. In this study, inspired by lotus leaves and mussels, a low-cost commercial polyurethane (PU) sponge was utilized as the substrate. Hydrophobic SiO₂ and magnetic Fe₃O₄ nanoparticles were modified by coating with self-polymerized dopamine to enhance surface roughness. The surface was chemically treated with fluorine-free, green, low-surface-energy polydimethylsiloxane (PDMS). Thus, a sponge exhibiting both superhydrophobic and superoleophilic properties was synthesized via impregnation technology. The results indicated that the modified PU sponge exhibited a water contact angle of 151.3°. The sponge demonstrated significant adsorption capacity for various oils and organic solvents, ranging from 20.55 to 33.63 times its own weight. The adsorption capacity remained stable after 10 separation cycles. Using gravity-driven flow or a peristaltic pump, the modified PU sponge achieved continuous oil-water separation with efficiency exceeding 97 %. The modified PU sponge demonstrated effective separation of toluene-in-water emulsions. It exhibited outstanding magnetic responsiveness, enabling rapid oil adsorption under magnetic guidance, and showed excellent flame retardancy to mitigate fire risks. This multifunctional polyurethane sponge, developed through synergistic modification, demonstrated significant potential for oil-water separation and environmental remediation applications.
通讯机构：
[Chai, B ; Xiao, JR] W;Wuhan Polytech Univ, Sch Chem & Environm Engn, Wuhan 430023, Peoples R China.
关键词：
CoS x /Mn 0.3 Cd 0.7 S heterojunction;Photocatalytic H 2 production;Charge separation and transfer mechanism
摘要：
Design and development of robust, stable and efficient photocatalysts is still a significant challenge in photocatalytic field. Herein, a 3D/1D CoS x /Mn 0.3 Cd 0.7 S heterojunction photocatalysts were prepared by coupling ZIF-67 polyhedron derived 3D CoS x with 1D rod-shaped Mn 0.3 Cd 0.7 S via solvothermal procedure, which greatly improved the efficiency of charge separation and photocatalytic H 2 production activity. Among these heterojunctions, CoS x /Mn 0.3 Cd 0.7 S-8, with a theoretical molar ratio of 1:8, demonstrated the best photocatalytic H 2 production performance, achieving a rate of 1060 μmol·h⁻¹, which is 5.2-fold increase compared to Mn 0.3 Cd 0.7 S alone. Its apparent quantum efficiency (AQE) reached around 8.1% under the irradiation using 420 nm monochromatic light. The excellent performance of CoS x /Mn 0.3 Cd 0.7 S heterojunction might be attributed to the accelerated separation and transfer efficiency of photo-induced carriers, according to the photoelectrochemical, photoluminescence (PL) and time-resolved photoluminescence emission spectra (TRPL) and electron paramagnetic resonance (EPR) tests. Based on the established band gap positions and ultraviolet photoelectron spectroscopy (UPS) results, the enhanced photocatalytic H 2 production performance might be explained by the mechanism of Schottky heterojunction between CoS x and Mn 0.3 Cd 0.7 S. This study aims to offer valuable insights for the construction of efficient catalysts for photocatalytic H 2 evolution.
Design and development of robust, stable and efficient photocatalysts is still a significant challenge in photocatalytic field. Herein, a 3D/1D CoS x /Mn 0.3 Cd 0.7 S heterojunction photocatalysts were prepared by coupling ZIF-67 polyhedron derived 3D CoS x with 1D rod-shaped Mn 0.3 Cd 0.7 S via solvothermal procedure, which greatly improved the efficiency of charge separation and photocatalytic H 2 production activity. Among these heterojunctions, CoS x /Mn 0.3 Cd 0.7 S-8, with a theoretical molar ratio of 1:8, demonstrated the best photocatalytic H 2 production performance, achieving a rate of 1060 μmol·h⁻¹, which is 5.2-fold increase compared to Mn 0.3 Cd 0.7 S alone. Its apparent quantum efficiency (AQE) reached around 8.1% under the irradiation using 420 nm monochromatic light. The excellent performance of CoS x /Mn 0.3 Cd 0.7 S heterojunction might be attributed to the accelerated separation and transfer efficiency of photo-induced carriers, according to the photoelectrochemical, photoluminescence (PL) and time-resolved photoluminescence emission spectra (TRPL) and electron paramagnetic resonance (EPR) tests. Based on the established band gap positions and ultraviolet photoelectron spectroscopy (UPS) results, the enhanced photocatalytic H 2 production performance might be explained by the mechanism of Schottky heterojunction between CoS x and Mn 0.3 Cd 0.7 S. This study aims to offer valuable insights for the construction of efficient catalysts for photocatalytic H 2 evolution.
摘要：
The heavy metal lead (Pb), as a typical pollutant, poses a major threat to environmental ecology. Developing efficient and economical lead ions (Pb 2+ ) removal technologies from aqueous solutions has become an urgent task. In this study, the peanut shell biochar (BC) composite adsorbents functionalized with rod-shaped hydroxyapatite (HAP) were synthesized by a combination of high-temperature pyrolysis of peanut shells and in-situ solution precipitation technique. By optimizing the addition amount of BC, the HAP/BC-2 adsorbent presented the maximal adsorption capacity of 1302. 24 mg/g for Pb 2+ . The effects of solution pH value, adsorbent dose, contact time and co-existing ions on the adsorption performance were explored. The adsorption process conformed to the pseudo-secondary kinetics and Langmuir isotherm models, indicating that the process was predominantly governed by chemisorption and occurred on homogeneously distributed adsorption sites. Thermodynamic analysis indicated that the adsorption process was endothermic in nature and proceeds spontaneously. The main adsorption mechanisms for Pb 2+ over the HAP/BC-2 composite were considered to be electrostatic interaction, dissolution precipitation, complexation of surface functional groups and cation-π interaction. Following six successive adsorption-desorption cycles, the HAP/BC-2 composite maintained an adsorption capacity for Pb 2+ of up to 886 mg/g. In addition, the adsorbent demonstrated significant potential for the effective removal of Pb 2+ from real water systems, while also exhibiting a notable adsorption capacity for Cu 2+ and Cd 2+ ions. Overall, the findings indicated that the HAP/BC composites hold considerable promise as cost-effective, environmentally sustainable, and alternative adsorbents for the removal of Pb 2+ from aqueous solutions, making them suitable candidates for application in environmental remediation.
The heavy metal lead (Pb), as a typical pollutant, poses a major threat to environmental ecology. Developing efficient and economical lead ions (Pb 2+ ) removal technologies from aqueous solutions has become an urgent task. In this study, the peanut shell biochar (BC) composite adsorbents functionalized with rod-shaped hydroxyapatite (HAP) were synthesized by a combination of high-temperature pyrolysis of peanut shells and in-situ solution precipitation technique. By optimizing the addition amount of BC, the HAP/BC-2 adsorbent presented the maximal adsorption capacity of 1302. 24 mg/g for Pb 2+ . The effects of solution pH value, adsorbent dose, contact time and co-existing ions on the adsorption performance were explored. The adsorption process conformed to the pseudo-secondary kinetics and Langmuir isotherm models, indicating that the process was predominantly governed by chemisorption and occurred on homogeneously distributed adsorption sites. Thermodynamic analysis indicated that the adsorption process was endothermic in nature and proceeds spontaneously. The main adsorption mechanisms for Pb 2+ over the HAP/BC-2 composite were considered to be electrostatic interaction, dissolution precipitation, complexation of surface functional groups and cation-π interaction. Following six successive adsorption-desorption cycles, the HAP/BC-2 composite maintained an adsorption capacity for Pb 2+ of up to 886 mg/g. In addition, the adsorbent demonstrated significant potential for the effective removal of Pb 2+ from real water systems, while also exhibiting a notable adsorption capacity for Cu 2+ and Cd 2+ ions. Overall, the findings indicated that the HAP/BC composites hold considerable promise as cost-effective, environmentally sustainable, and alternative adsorbents for the removal of Pb 2+ from aqueous solutions, making them suitable candidates for application in environmental remediation.
作者机构：
[Fan, Linkun; Feng, Xinya; Wang, Xusheng; Shen, Tianqi; Khan, Usman; Wang, XS] Zhejiang Sci Tech Univ, Sch Mat Sci & Engn, State Key Lab Biobased Fiber Mat, Hangzhou 310018, Peoples R China.;[Li, Lan] China Jiliang Univ, Coll Mat & Chem, Hangzhou 310018, Peoples R China.;[Zhang, Yiming] Lanzhou Univ Technol, Sch Mat Sci & Engn, Lanzhou 730050, Peoples R China.;[Chai, Bo] Wuhan Polytech Univ, Sch Chem & Environm Engn, Wuhan 430023, Peoples R China.;[Wang, Xusheng; Wang, XS] Zhejiang Sci Tech Univ, Shengzhou Innovat Res Inst, Shengzhou 312400, Zhejiang, Peoples R China.
通讯机构：
[Wang, XS ] Z;Zhejiang Sci Tech Univ, Sch Mat Sci & Engn, State Key Lab Biobased Fiber Mat, Hangzhou 310018, Peoples R China.;Zhejiang Sci Tech Univ, Shengzhou Innovat Res Inst, Shengzhou 312400, Zhejiang, Peoples R China.
摘要：
Photocatalytic nitrogen fixation is a promising strategy for sustainable energy production, with efficient and cost-effective photocatalysts being crucial for its success. In this study, oxygen vacancy-rich photocatalysts (100-U, 200-U, and 300-U) were successfully synthesized via low-temperature calcination of NH2-UiO-66. Electron paramagnetic resonance analysis confirmed a significant increase in oxygen vacancies during calcination, enhancing active sites for photogenerated charge carrier capture. The bond length, thermogravimetric analysis, and X-ray diffraction revealed that calcination at 200 degrees C, compared to other temperatures, led to the cleavage of C1-C2 bonds and the breakage of Zr-OH-Zr bonds, promoting oxygen vacancy formation while preserving structural integrity. Photocatalytic results showed that the 200-U sample exhibited the highest nitrogen fixation performance, with an NH3 yield of 17.2 mu mol g-1 h-1, approximately twice that of the original NH2-UiO-66. This work provides valuable insights into the partial decomposition process and oxygen vacancy formation mechanism, contributing to the design of photocatalysts with abundant oxygen vacancies.
通讯机构：
[Chen, H ; Zhang, XH; Dai, K ] H;Huazhong Agr Univ, Coll Chem, Wuhan 430070, Peoples R China.;Huazhong Agr Univ, Coll Resources & Environm, Wuhan 430070, Peoples R China.
关键词：
Photocatalysis;Hydrogen production;Conjugated polymer;Linkage site regulation;Structure-activity relationship
摘要：
Conjugated polymers have great application prospects in photocatalytic hydrogen production due to their easy availability and adjustable structure. However, their photocatalytic properties are usually affected by photogenerated charge recombination. In this paper, a strategy for controlling the linkage positions of naphthalene-based conjugated polymers between naphthalene (N) and dibenzothiophene-S, S-dioxide (BDTO) is proposed, and N1-BDTO polymer is designed by linking BDTO on α-site of N unit, while N2-BDTO, N3-BDTO and N4-BDTO polymers are synthesized by linking BDTO on different β-site of N unit. Photoelectrochemistry experimental results show that N1-BDTO exhibits higher photogenerated e − /h + separation efficiency than that of N2-BDTO, N3-BDTO and N4-BDTO. Photocatalytic hydrogen production rate of N1-BDTO is 1.65, 17.76 and 4.95 times higher than that of N2-BDTO, N3-BDTO and N4-BDTO respectively. And the hydrogen production rate of N1-BDTO reaches to 749.24 μmol/h after reaction condition optimization. In addition, high apparent quantum yield (AQY) of 5.03% at 450 nm monochromatic light is obtained. The performance advantage of N1-BDTO material is attributed to the strong electron cloud density of the α-site according to theoretical analysis, which promotes the separation and transfer of charge carriers. This study provides a new idea for design of efficient conjugated polymer photocatalysts.
Conjugated polymers have great application prospects in photocatalytic hydrogen production due to their easy availability and adjustable structure. However, their photocatalytic properties are usually affected by photogenerated charge recombination. In this paper, a strategy for controlling the linkage positions of naphthalene-based conjugated polymers between naphthalene (N) and dibenzothiophene-S, S-dioxide (BDTO) is proposed, and N1-BDTO polymer is designed by linking BDTO on α-site of N unit, while N2-BDTO, N3-BDTO and N4-BDTO polymers are synthesized by linking BDTO on different β-site of N unit. Photoelectrochemistry experimental results show that N1-BDTO exhibits higher photogenerated e − /h + separation efficiency than that of N2-BDTO, N3-BDTO and N4-BDTO. Photocatalytic hydrogen production rate of N1-BDTO is 1.65, 17.76 and 4.95 times higher than that of N2-BDTO, N3-BDTO and N4-BDTO respectively. And the hydrogen production rate of N1-BDTO reaches to 749.24 μmol/h after reaction condition optimization. In addition, high apparent quantum yield (AQY) of 5.03% at 450 nm monochromatic light is obtained. The performance advantage of N1-BDTO material is attributed to the strong electron cloud density of the α-site according to theoretical analysis, which promotes the separation and transfer of charge carriers. This study provides a new idea for design of efficient conjugated polymer photocatalysts.
通讯机构：
[Chai, B ] W;Wuhan Polytech Univ, Sch Chem & Environm Engn, Wuhan 430023, Peoples R China.
关键词：
Co 9 S 8 /Mn 0.3 Cd 0.7 S heterojunction;Photocatalytic H 2 evolution;Charge separation and transfer;Photocatalytic mechanism
摘要：
One of the most crucial strategies for transforming solar energy into sustainable hydrogen energy is photocatalytic H2 evolution, and constructing an effective and durable photocatalyst remains a difficult task. Herein, a 1D/3D Co9S8/Mn0.3Cd0.7S Schottky heterojunctions were successfully fabricated by three-step hydrothermal procedure, in which 3D Mn0.3Cd0.7S solid solution particles were immobilized on the 1D tube -like Co9S8 surface, allowing for extremely effective charge separation and transfer. Through coupling Co9S8 with Mn0.3Cd0.7S, the photocatalytic H2 evolution activity and stability were significantly boosted. The 7 % Co9S8/Mn0.3Cd0.7S heterojunction possessed the highest photocatalytic activity with the H2 evolution rate of 1586.4 mu mol center dot h-1, which was 3.73 times larger than that of pristine Mn0.3Cd0.7S, corresponding to 21.8 % apparent quantum efficiency (AQE) at 420 nm monochromatic light. The Schottky heterojunction mechanism between Co9S8 and Mn0.3Cd0.7S could plausibly explain the enhanced photocatalytic H2 evolution performance, according to density functional theory (DFT) calculations and ultraviolet photoelectron spectroscopy (UPS) measurements. This investigation would offer the useful insights to develop Co9S8 cocatalyst for application in photocatalytic H2 evolution.
通讯机构：
[Ding, D; Jiang, Z ; Yan, JT ] W;Wuhan Polytech Univ, Coll Chem & Environm Engn, Wuhan 430023, Peoples R China.;Wuhan Univ, Sch Elect Engn & Automat, Wuhan 430072, Peoples R China.
关键词：
Photocatalysis;Layered structure;Charge transfer
摘要：
The photocatalytic activity of promising layered structure BiOX (X = Cl, Br, I) is limited by the low carrier mobility and charge transfer based on heterojunction. Hereon, we reported that Bi2O2Se with the same layered structure, high carrier mobility and broad spectrum absorption was used to composited with BiOCl to obtain effective layer to layer interfacial charge transfer and high photocatalytic activity under visible light. Bi2O2Se/ BiOCl were synthesized via ion exchange method in precursor of Bi2O2Se. 25-Bi2O2Se/BiOCl shows the optimal photocatalytic removal activity of methyl blue (MB) and Cr (VI), which was higher than that of pure BiOCl and Bi2O2Se. The analysis of morphology revealed the in-growth mechanism of Bi2O2Se/BiOCl. A strong interaction between the same layer structure Bi2O2Se and BiOCl was proved by detailed analysis of XPS and valence charge density. Transient photocurrent responses and energy-level indicated the sensitized electrons of Bi2O2Se can be injected into BiOCl effectively and produce H2O2. We believe layer structure Bi2O2Se can be candidate cocatalyst to expand photocatalytic activity of layer structure semiconductor catalysts in the visible and infrared regions, especially, for the same layered bismuth compounds.
摘要：
Photocatalytic CO(2) reduction into value-added chemical fuels using sunlight as the energy input has been a thorny, challenging and long-term project in the environment/energy fields because of to its low efficiency. Herein, a series of CdS/Co-BDC composite photocatalysts were constructed by incorporating CdS nanoparticles into Co-BDC using a dual-solvent in situ growth strategy for improving photocatalytic CO(2) reduction efficiency. The composites were characterized through XRD, SEM, TEM, XPS, DRS and EPR techniques in detail. 18% CdS/Co-BDC composites showed superior performance for the photocatalytic CO(2) reduction to CO, which was 8.9 and 19.6 times higher than that showed by the pure CdS and Co-BDC, respectively. The mechanism of enhanced photocatalytic CO(2) reduction performance was analyzed. The CdS/Co-BDC composites showed better adsorption for CO(2). Detailed analysis of XPS, transient photocurrent responses, and electrochemical impedance spectroscopy (EIS) shows the existence of strong charge interaction between CdS and Co-BDC and the photo-electrons of CdS can be transferred to Co-BDC. Additionally, Co-oxo of Co-BDC plays the role of a redox-active site and promotes the reduction performance via the method of valence transition of Co(ii)/Co(iii) redox.
通讯机构：
[Yan, JT ; Sun, Y] W;Wuhan Polytech Univ, Coll Chem & Environm Engn, Wuhan 430023, Peoples R China.
关键词：
Rice -straw lignin;Polyacryonitrile;Composite materials;Electrospinning method;Energy storage and conversion
摘要：
This study outlines the successful fabrication of composite membrane using rice-straw lignin/polyacrylonitrile (L-PAN) via electrospinning method, and evaluated as a lithium-ion battery separator. L-PANs exhibited higher porosity and superior electrolyte wettability compared to the commercial Celgard 2300. Remarkably, even after exposure to 150 degrees C for an hour, L-PANs showed minimal changes, whereas Celgard 2300 experienced notable shrinkage. As a separator for Li/LiFePO4 batteries, L-PANs demonstrated outstanding capacity retention of 97.7 % over 200 cycles and superior cycling performance compared to Celgard 2300. Collectively, this research offers a promising approach to valorizing waste rice straw resources and expanding the application of lignin in the field of lithium-ion battery.
期刊：
ACS Applied Energy Materials,2024年7(13):5418-5425 ISSN：2574-0962
通讯作者：
Sun, LC;Sun, Licheng;Fan, K
作者机构：
[Sun, LC; Sun, Licheng; Ding, Yunxuan; Wang, Linqin] Westlake Univ, Ctr Artificial Photosynth Solar Fuels, Sch Sci & Res Ctr Ind Future, Hangzhou 310024, Peoples R China.;[Chai, Bo] Wuhan Polytech Univ, Sch Chem & Environm Engn, Wuhan 430023, Peoples R China.;[Sun, LC; Sun, Licheng; Ding, Yunxuan; Wang, Linqin] Westlake Univ, Res Ctr Ind Future, Sch Sci, Dept Chem, Hangzhou 310024, Peoples R China.;[Sun, LC; Sun, Licheng; Ding, Yunxuan; Wang, Linqin] Westlake Univ, Div Solar Energy Convers & Catalysis, Zhejiang Baima Lake Lab Co Ltd, Hangzhou 310000, Zhejiang, Peoples R China.;[Jia, Yufei; Fan, Ke; Sun, Licheng; Sun, LC; Li, Yaqing] Dalian Univ Technol, DUT KTH Joint Educ & Res Ctr Mol Devices, Inst Artificial Photosynth,Frontier Sci Ctr Smart, Inst Energy Sci & Technol,State Key Lab Fine Chem, Dalian 116024, Peoples R China.
通讯机构：
[Fan, K ; Sun, LC] D;[Sun, LC ] W;Westlake Univ, Ctr Artificial Photosynth Solar Fuels, Sch Sci & Res Ctr Ind Future, Hangzhou 310024, Peoples R China.;Westlake Univ, Res Ctr Ind Future, Sch Sci, Dept Chem, Hangzhou 310024, Peoples R China.;Westlake Univ, Div Solar Energy Convers & Catalysis, Zhejiang Baima Lake Lab Co Ltd, Hangzhou 310000, Zhejiang, Peoples R China.
摘要：
Bismuth-based catalysts have demonstrated significant electrocatalytic activity in the electrochemical CO2 reduction reaction (CO2RR) to produce formate/formic acid, while the morphology of these catalysts is considered to be crucial for their electrocatalytic performance. However, the potential topological transformation of Bi-based catalysts during CO2RR catalysis has been largely overlooked, which could lead to an underlying lack of understanding of the structure-activity relationship. In this study, various morphologies of bismuth sulfide (Bi2S3), including nanowires, nanoribbons, nanospheres, nanoparticles, and commercially available bulk powders of Bi2S3, were systematically investigated for the electrocatalytic CO2RR in a 1 M KOH electrolyte. Surprisingly, all of these morphologies exhibit excellent electrocatalytic activities for formate synthesis, with high Faradaic efficiencies exceeding 90%. Meanwhile, no significant distinction could be observed regarding their catalytic performance during long-term operation. During the CO2RR process, all Bi2S3 morphologies initially turn into similar nanocomposites of Bi and Bi2O2CO3 sheets, which subsequently undergo a topotactic transformation into metallic Bi nanoparticles. Theoretical calculations indicate that such a topotactic transformation is conducive to the CO2RR due to the superior activity and selectivity of metallic Bi nanoparticles. These findings shed light on the impact of the topotactic transformation of bismuth-based catalysts on the CO2RR, providing insights into the structure-activity relationship.
摘要：
A novel cellulose composite (denoted as PEI@MMA-1) with porous interconnected structure was prepared by adsorbing methyl cellulose (MC) onto microcrystalline cellulose (MCC) and cross-linking polyethyleneimine (PEI) with MCC by the action of epichlorohydrin, which had the excellent adsorption property, wettability and elasticity. The performances of PEI@MMA-1 composite for removing tetracycline (TC), Cu(2+) and coexistent pollutant (TC and Cu(2+) mixture) were systematically explored. For single TC or Cu(2+) contaminant, the maximum adsorption capacities were 75.53 and 562.23mg/g at 30°C, respectively, while in the dual contaminant system, they would form complexes and Cu(2+) could play a "bridge" role to remarkably promote the adsorption of TC with the maximum adsorption capacities of 281.66 and 253.58mg/g for TC and Cu(2+). In addition, the adsorption kinetics, isotherms and adsorption mechanisms of single-pollutant and dual-pollutant systems have been thoroughly investigated. Theoretical calculations indicated that the amide group of TC molecule with the assistance of Cu(2+) interacted with the hydroxyl group of PEI@MMA-1 composite to enhance the TC adsorption capacity. Cycle regeneration and fixed bed column experiments revealed that the PEI@MMA-1 possessed the excellent stability and utility. Current PEI@MMA-1 cellulose composite exhibited a promising application for remediation of heavy metals and antibiotics coexistence wastewater.
摘要：
Cr(VI) stands as a profoundly toxic chemical and photocatalysis technology has shown promising potential in photocatalytic reduction of Cr(VI) to Cr(III), where the reduced Cr(III) is less toxic and can be further precipitated in a wide pH range. Metal-organic frameworks (MOFs), as emerging class of porous coordination polymers, is expected to be ideal platform for photocatalysis. In this study, defect engineering on MOFs was applied to promote photoreduction of Cr(VI). The obtained oxygen vacancy-containing MIL-125-NH2 samples showed modified electron structure, adjusted surface and porous properties, and enriched active sites. Among these oxygen vacancy-containing MIL-125-NH2 samples, the 300-M (MIL-125-NH2 heated at 300 °C for 2 h under N2 atmosphere) displayed the most remarkable performance in terms of photocatalytic Cr(VI) reduction. The pronounced efficacy of 300-M is evident from the achieved removal rate of Cr (VI), reaching an impressive 98 % in just 20 mins (19.6 mgCr(VI) g−1cata min−1), in stark contrast to MIL-125-NH2, which exhibited a modest removal rate of 53 %. Remarkably, the k-value for 300-M is 5.1 times that of MIL-125-NH2, further underscoring the superior efficiency of 300-M. The photoreduction mechanism of 300-M was further substantiated through a battery of advanced characterization techniques including transient photocurrent, electrochemical impedance spectroscopy, fluorescence spectroscopy, the Mott-Schottky analysis, and electron spin resonance. Those results disclosed that oxygen vacancies and mesopores introduced via controlled heat treatment play a pivotal role in facilitating the photoreduction of Cr(VI) within the MIL-125-NH2 structure. More advanced characterizations for the structures of photocatalysts and the photocatalytic mechanisms including charge transfer path need further studied. The systematic exploration of temperature-dependent effects on material properties opens avenues for future research in designing efficient and versatile MOF-based photocatalysts for environmental remediation applications.
Cr(VI) stands as a profoundly toxic chemical and photocatalysis technology has shown promising potential in photocatalytic reduction of Cr(VI) to Cr(III), where the reduced Cr(III) is less toxic and can be further precipitated in a wide pH range. Metal-organic frameworks (MOFs), as emerging class of porous coordination polymers, is expected to be ideal platform for photocatalysis. In this study, defect engineering on MOFs was applied to promote photoreduction of Cr(VI). The obtained oxygen vacancy-containing MIL-125-NH2 samples showed modified electron structure, adjusted surface and porous properties, and enriched active sites. Among these oxygen vacancy-containing MIL-125-NH2 samples, the 300-M (MIL-125-NH2 heated at 300 °C for 2 h under N2 atmosphere) displayed the most remarkable performance in terms of photocatalytic Cr(VI) reduction. The pronounced efficacy of 300-M is evident from the achieved removal rate of Cr (VI), reaching an impressive 98 % in just 20 mins (19.6 mgCr(VI) g−1cata min−1), in stark contrast to MIL-125-NH2, which exhibited a modest removal rate of 53 %. Remarkably, the k-value for 300-M is 5.1 times that of MIL-125-NH2, further underscoring the superior efficiency of 300-M. The photoreduction mechanism of 300-M was further substantiated through a battery of advanced characterization techniques including transient photocurrent, electrochemical impedance spectroscopy, fluorescence spectroscopy, the Mott-Schottky analysis, and electron spin resonance. Those results disclosed that oxygen vacancies and mesopores introduced via controlled heat treatment play a pivotal role in facilitating the photoreduction of Cr(VI) within the MIL-125-NH2 structure. More advanced characterizations for the structures of photocatalysts and the photocatalytic mechanisms including charge transfer path need further studied. The systematic exploration of temperature-dependent effects on material properties opens avenues for future research in designing efficient and versatile MOF-based photocatalysts for environmental remediation applications.
摘要：
Heavy metal lead (Pb2+) contamination in water poses a serious threat to human health, and developing some effective strategies for the removal of Pb2+ is urgent. Herein, molybdenum disulfide (MoS2) anchored peanut shell biochar (BC) composite adsorbents were successfully prepared by hydrothermal method and applied for the adsorption of Pb2+. Among these composites, the MoS2/BC-3 composite displayed the best adsorption performance with the adsorption capacity of 232 mg center dot g(-1) at 30 degrees C. The adsorption procedure followed the pseudosecondary kinetics and Freundlich adsorption model, indicating that the adsorption process of Pb2+ over MoS2/BC-3 composite was chemical and multilayer adsorption. Moreover, Pb2+ was spontaneously adsorbed by MoS2/BC-3, and the adsorption capacity increased with the enhance of temperature. The main mechanisms involved in the adsorption of Pb2+ by MoS2/BC-3 composite were found to include electrostatic interaction and complexation interaction. In addition, the MoS2/BC-3 composite had a good stability, and the Pb2+ removal rate could still reach more than 80 % after 6 cycles of adsorption experiments. Meanwhile, the adsorbent demonstrated a strong ability to absorb common heavy metals including copper and cadmium, further confirming that the MoS 2 /BC-3 composite had a potential value.
