作者机构:
[Quan, Fengjiao; Xu, Pengfei; Chen, Xiaolan; Shen, Wenjuan; He, Yun; Li, Jianfen] College of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, China;[Jia, Falong] College of Chemistry, Central China Normal University, Wuhan 430079, China;[Zhan, Guangming] School of Environmental Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, China
通讯机构:
[Falong Jia] C;College of Chemistry, Central China Normal University, Wuhan 430079, China
摘要:
Nitrate (NO3–) is a widespread pollutant in high-salt wastewater and causes serious harm to human health. Although electrochemical removal of nitrate has been demonstrated to be a promising treatment method, the development of low-cost electro-catalysts is still challenging. In this work, a phosphate modified iron (P-Fe) cathode was prepared for electrochemical removal of nitrate in high-salt wastewater. The phosphate modification greatly improved the activity of iron, and the removal rate of nitrate on P-Fe was three times higher than that on Fe electrode. Further experiments and density functional theory (DFT) calculations demonstrated that the modification of phosphoric acid improved the stability and the activity of the zero-valent iron electrode effectively for NO3– removal. The nitrate was firstly electrochemically reduced to ammonium, and then reacted with the anodic generated hypochlorite to N2. In this study, a strategy was developed to improve the activity and stability of metal electrode for NO3– removal, which opened up a new field for the efficient reduction of NO3– removal by metal electrode materials.
作者机构:
[Yu Zhou; Nan Wang; Lihua Zhu] College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China;College of Chemistry and Chemical Engineering, Hubei Polytechnic University, Huangshi 435003, China;College of Chemistry and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, China;[Shuangshuang Huang] School of Physics and Technology, Center for Electron Microscopy, Wuhan University, Wuhan, China;[Xiaobo Wang] College of Chemistry and Chemical Engineering, Hubei Polytechnic University, Huangshi 435003, China<&wdkj&>College of Chemistry and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, China
通讯机构:
[Xiaobo Wang; Lihua Zhu] C;College of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China<&wdkj&>College of Chemistry and Chemical Engineering, Hubei Polytechnic University, Huangshi 435003, China<&wdkj&>College of Chemistry and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, China
摘要:
An efficient catalytic system was developed to remove various organic pollutants by simultaneously using low-level cobalt ions, calcium carbonate micro-particles and peroxymonosulfate (PMS). A simple base-induced precipitation was used to successfully loaded Co-centered reactive sites onto the surface of CaCO3 microparticles. Under optimal conditions at 25 °C, 10 mg/L methylene blue (MB) could be completely degraded within 10 min with 480 µg/L Co2+, 0.4 g/L CaCO3 microparticles (or 0.4 g/L Co@CaCO3) and 0.1 g/L PMS. The MB degradation followed the pseudo first order kinetics with a rate constant of 0.583 min−1, being 8.3, 11.5 and 53.0 times that by using Co-OH (0.07 min−1), Co2+ (0.044 min−1) and CaCO3 (0.011 min−1) as the catalyst, respectively. It was confirmed that there was a synergistic effect in the catalytic activity between Co species and the CaCO3 particles but the major contributor was the highly dispersed Co species. When Co2+-containing simulated electroplating wastewater was used as the Co2+ source, not only the added MB was also completely degraded within 5 min in this catalytic system, but also the coexisting heavy metal ions were substantially removed. The presently developed method was applied to simultaneously treat organic wastewater and heavy metals wastewater. The present method was also successfully used to efficiently degrade other organic pollutants including bisphenol A, sulfamethoxazole, rhodamine B, tetrabromobisphenol A, ofloxacin and benzoic acid. A catalytic mechanism was proposed for the PMS activation by Co@CaCO3. The surface of CaCO3 particles favors the adsorption of Co2+. More importantly, the surface of CaCO3 particles provides plentiful surface -OH and -CO32+, and these surface groups complex with Co2+ to produce more catalytically active species such as surface [CoOH]−, resulting in rapid Co2+/Co3+ cycling and electron transfer. These interactions cause the observed synergistic effect between Co species and CaCO3 particles in PMS activation. Due to good cycle stability, strong anti-interference ability and wide universality, the new method will have broad application prospects.
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.
关键词:
NH3-SCR reaction;low temperature;different solid contents;Mn/TiO2 catalysts;degradation of NO
摘要:
Mn/TiO2 catalysts with varying solid contents were innovatively prepared by the sol-gel method and were used for selective catalytic reduction of NO at low temperatures using NH3 (NH3-SCR) as the reducing agent. Surprisingly, it was found that as the solid content of the sol increased, the catalytic activity of the developed Mn/TiO2 catalyst gradually increased, showing excellent catalytic performance. Notably, the Mn/TiO2 (50%) catalyst demonstrates outstanding denitration performance, achieving a 96% NO conversion rate at 100 degrees C under a volume hourly space velocity (VHSV) of 24,000 h(-1), while maintaining high N-2 selectivity and stability. It was discovered that as the solid content increased, the catalyst's specific surface area (SSA), surface Mn4+ concentration, chemisorbed oxygen, chemisorption of NH3, and catalytic reducibility all improved, thereby enhancing the catalytic efficiency of NH3-SCR in degrading NO. Moreover, NH3 at the Lewis acidic sites and NH4+ at the Bronsted acidic sites of the catalyst were capable of reacting with NO. Conversely, NO and NO2 adsorbed on the catalyst, along with bidentate and monodentate nitrates, were unable to react with NH3 at low temperatures. Consequently, the developed catalyst's low-temperature catalytic reaction mechanism aligns with the E-R mechanism.
摘要:
To enhance the application range of flexible films, it is crucial to rationally design composite films with high stretchability, excellent thermal conductivity, and water resistance. Flexible composite films with nanocellulose (CNF)-modified expanded graphite and spun fibers loaded with phase change materials as the backbone were obtained by electrospinning method. The prepared materials were characterized by good tensile properties (328.32%), high latent heat (107.0 J/g), good thermal stability, high photo-thermal conversion efficiency, good reusability, flame retardant properties, UV resistance and visible light absorption properties. What's more, the performance of the flexible composite membrane is adjustable. The prepared flexible composite membranes are promising in the fields of solar thermal energy conversion, wearable flexible materials and renewable energy utilization.
通讯机构:
[Xu, B ] W;Wuhan Polytech Univ, Hubei Prov Engn Technol Res Ctr Agr & Sideline Res, Sch Chem & Environm Engn, Wuhan 430023, Peoples R China.
摘要:
Polyimide aerogels (PIAs) not only possess excellent thermodynamic properties but also have a high porosity structure, making them an exceptional protective and thermal insulation material, and further broadening their application scope in aerospace and other cutting-edge fields. In this work, a series of anisotropic polyimide aerogels (3,3 ',4,4 '-biphenyltetracarboxylic dianhydride (S-BPDA), p-phenylenediamine (PDA), 4,4 '-diaminodiphenyl ether (ODA)) with excellent properties were prepared. These PIAs were obtained by unidirectional freeze-drying and thermal amination of two different precursor solutions mixed in proportion. These PIAs possess an irregularly oval tubular structure, exhibiting pronounced anisotropy. (PIA-2 exhibits outstanding flexible resilience in the radial direction. It can still regain its original form after half an hour of compression by a universal testing machine, yet it cannot do so in the axial direction. The thermal diffusivity of PIA-5 in the radial direction at room temperature is as low as 0.067 mm2 s-1, and even at 200 degrees C, the thermal diffusivity is as low as 0.057 mm2 s-1. Meanwhile, the thermal diffusivity in the axial direction at room temperature is 0.11 mm2 s-1, surpassing the value of 0.106 mm2 s-1 of aerogels prepared from monomeric raw materials and dried under supercritical conditions). PIAs exhibit outstanding thermal stability (the axial strength and modulus retention of PIA-8 at 200 degrees C are as high as 52.63% and 44.82%), and its weight loss temperature of 5% is as high as 603 degrees C and it has a glass softening temperature of 387 degrees C. PIAs also demonstrate exceptional flame retardancy in imitation flame retardant experiments and exhibit outstanding thermal insulation performance when heated on a 150 degrees C heating plate for 10 minutes (the radial surface temperature of PIA-5 was only 49.9 degrees C). These anisotropic PIAs materials exhibit outstanding flexible resilience, and thermal protection performance, holding significant importance for their widespread adoption as thermal insulation materials in aerospace, high-precision electronic components, and other domains. Anisotropic polyimide aerogels for thermal protection with outstanding flexible resilience.
关键词:
Industrial wastewater;Fluoride;Monolayer Ca-Y LRH;Adsorption;Rapid and efficient removal
摘要:
Strategies for the rapid and efficient removal of fluoridated industrial wastewater are currently lacking. Herein, monolayer calcium-doped layered yttrium hydroxide (Ca-Y LRH) was synthesized through formamide exfoliation, and its removal of fluoride reached equilibrium within 4 min. The adsorption kinetics fit the pseudo-secondorder kinetic model with a faster adsorption rate (KF = 0.22 mg g- 1 min- 1), and the adsorption isotherm followed the Langmuir model with a maximum adsorption capacity of 483.33 mg g-1. The interlayer chloride ions in the monolayer Ca-Y LRH were the main ligands for substituting fluoride, which inhibited the increase in pH and maintained the continuation of the fluoride removal process. Furthermore, the optimum fluoride removal performance of monolayer Ca-Y LRH was predicted by software-based multiparameter methods and was found to be useful for treating fluoridated industrial wastewater samples (858.17 or 8.72 mg L-1). These findings provide novel insights into the treatment of fluoridated industrial wastewater.
期刊:
Chemical Engineering Journal,2024年481:148501 ISSN:1385-8947
通讯作者:
Bo Chai
作者机构:
[Huang, Junxin; Chai, Bo; Xiao, Jiangrong; Fan, Guozhi; Song, Guangsen] School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, P. R. China;[Zhang, Xiaohu] College of Chemistry, Huazhong Agricultural University, Wuhan 430070, P. R. China
通讯机构:
[Bo Chai] S;School of Chemical and Environmental Engineering, Wuhan Polytechnic University, Wuhan 430023, P. R. China
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 μmol⋅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.
摘要:
Excess phosphorus (P) in surface water poses a serious threat to ecological safety. However, current methods for effectively removing low concentrations of phosphorus are complicated and expensive. Herein, we used one-step mechanical activation to enhance the release of alkalinity from carbonates and to stimulate ferrous activity in situ, thus achieving efficient and stable removal of phosphorus at low concentrations. The resultant activated FeCO 3 was demonstrated to be a high-performance material, which can remove more than 92 % of the actual low concentration of phosphorus pollution within 30 min, and the concentration of the effluent steadily met the requirements of Chinese Class I environmental quality standards for surface water (0.02 mg/L). In addition, mechanistic investigation showed that mechanical activation significantly enhanced the reactivity and phosphorus removal performance of MgCO 3 . Moreover, one-step mechanical activation simultaneously stimulates the release of alkaline and ferrous ionic groups from iron -rich FeCO 3 , which can produce highly active trivalent iron oxides in situ, leading to efficient and stable phosphorus removal at low concentrations. The present work provides a new insight and direction for developing high-performance materials to remediate low concentration phosphorus polluted waters.
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.
摘要:
Photocatalytic CO2 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 CO2 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 CO2 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 CO2 reduction performance was analyzed. The CdS/Co-BDC composites showed better adsorption for CO2. 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.
摘要:
The recovery of Au(III) has become a focal point of interest due to its significance in resource utilization and addressing environmental contamination. In this study, [C(3)NH(2)Mim]Cl-CMPS and PPh3-CMPS were successfully developed by immobilizing [C(3)NH(2)Mim]Cl and triphenylphosphine (PPh3) onto chloromethylated polystyrene beads (CMPS). The adsorbents demonstrated consistently high adsorption efficiency (>95 %) at a wide pH range. The [C(3)NH(2)Mim]Cl-CMPS and PPh3-CMPS exhibited exceptional selective adsorption ability for Au(III), and the adsorption process adhered to the PSO and Langmuir model. The adsorption efficiency of Au(III) remained constant after five consecutive cycles, highlighting outstanding reusability performance. Furthermore, as the existence of multiple coexisting metal ions, [C(3)NH(2)Mim]Cl-CMPS and PPh3-CMPS could efficiently and selectively capture Au(III) from the gold slag and PCBs lixivium, which is promising for Au recovery in practice.
摘要:
The increasingly severe antibiotic pollution has become one of the most critical issues. In this study, a zinc peroxide/peroxymonosulfate (ZnO(2)/PMS) double-oxidation system was developed for tetracycline (TC) degradation. A small amount of ZnO(2) (10 mg) and PMS (30 mg) could effectively degrade 82.8% of TC (100 mL, 50 mg/L), and the degradation process could be well described by the pseudo-second-order kinetic model. Meanwhile, the ZnO(2)/PMS double-oxidation system showed high adaptability in terms of reaction temperature (2-40 °C), initial pH value (4-12), common inorganic anions (Cl(-), NO(3)(-), SO(4)(2-) and HCO(3)(-)), natural water source and organic pollutant type. The quenching experiment and electron paramagnetic resonance (EPR) characterization results confirmed that the main reactive oxygen species (ROS) was singlet oxygen ((1)O(2)). Moreover, three possible pathways of TC degradation were deduced according to the analyses of intermediates. On the basis of comparative characterization and experiment results, a synergistic activation mechanism was further proposed for the ZnO(2)/PMS double-oxidation system, accounting for the superior degradation performance. The released OH(-) and H(2)O(2) from ZnO(2) could activate PMS to produce major (1)O(2) and minor superoxide radicals (•O(2)(-)), respectively.
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:
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:
A new direct immersion dual-drop microextraction (DIDDME) procedure is described for Fe(III) and Fe(II) speciation followed by detection with graphite furnace atomic absorption spectrometry. This method is based upon the selective reaction of 1-(2-pyridylazo)-2-naphthol (PAN) and N-benzoyl-N-phenylhydroxylamine (BPHA) with Fe(II) and Fe(III) to form complexes at pH 1.5. Two solvent drops that contain PAN and BPHA were concurrently immersed in a sample solution for simultaneous separation of Fe(III) and Fe(II), respectively. This method eliminated time-consuming and labor-intensive oxidation of Fe(II) or reduction of Fe(III), which may provide incomplete conversion and contamination. Using the optimal conditions, the detection limits were 0.067 ng mL−1 and 0.054 ng mL−1 for Fe(II) and Fe(III) with relative standard deviations of 6.0% and 5.1%, respectively. Enrichment factors of 300-fold were obtained. The procedure was successfully utilized for the determination of Fe(II) and Fe(III) in Chinese yellow wine. To evaluate accuracy of this method, a rice certified reference material was analyzed and the result was in good agreement with the certified value.
摘要:
<jats:title>Abstract</jats:title><jats:p>In the last few decades, nanoparticles have been a prominent topic in various fields, particularly in agriculture, due to their unique physicochemical properties. Herein, molybdenum copper lindgrenite Cu<jats:sub>3</jats:sub>(MoO<jats:sub>4</jats:sub>)<jats:sub>2</jats:sub>(OH)<jats:sub>2</jats:sub> (CM) nanoflakes (NFs) are synthesized by a one-step reaction involving <jats:italic>α</jats:italic>-MoO<jats:sub>3</jats:sub> and CuCO<jats:sub>3</jats:sub>⋅Cu(OH)<jats:sub>2</jats:sub>⋅<jats:italic>x</jats:italic>H<jats:sub>2</jats:sub>O solution at low temperature for large scale industrial production and developed as an effective antifungal agent for the oilseed rape. This synthetic method demonstrates great potential for industrial applications. Infrared spectroscopy and X-ray diffraction (XRD) results reveal that CM samples exhibit a pure monoclinic structure. TG and DSC results show the thermal stable properties. It can undergo a phase transition form copper molybdate (Cu<jats:sub>3</jats:sub>Mo<jats:sub>2</jats:sub>O<jats:sub>9</jats:sub>) at about 300°C. Then Cu<jats:sub>3</jats:sub>Mo<jats:sub>2</jats:sub>O<jats:sub>9</jats:sub> nanoparticlesdecompose into at CuO and MoO<jats:sub>3</jats:sub> at 791°C. The morphology of CM powder is mainly composed of uniformly distributed parallelogram-shaped nanoflakes with an average thickness of about 30nm. Moreover, the binding energy of CM NFs is measured to be 2.8eV. To assess the antifungal properties of these materials, both laboratory and outdoor experiments are conducted. In the pour plate test, the minimum inhibitory concentration (MIC) of CM NFs against <jats:italic>Sclerotinia sclerotiorum (S. sclerotiorum)</jats:italic> is determined to be 100ppm, and the zone of inhibiting <jats:italic>S. sclerotiorum</jats:italic> is 14mm. When the concentration is above 100nm, the change rate of the hyphae circle slows down a little and begins to decrease until to 200ppm. According to the aforementioned findings, the antifungal effects of a nano CM NFs solution are assessed at different concentrations (0ppm (clear water), 40ppm, and 80ppm) on the growth of oilseed rape in an outdoor setting. The results indicate that the application of CM NFs led to significant inhibition of <jats:italic>S. sclerotiorum</jats:italic>. Specifically, when the nano CM solution was sprayed once at the initial flowering stage at a concentration of 80ppm, <jats:italic>S. sclerotiorum</jats:italic> growth was inhibited by approximately 34%. Similarly, when the solution was sprayed once at the initial flowering stage and once at the rape pod stage, using a concentration of 40ppm, a similar level of inhibition was achieved. These outcomes show that CM NFs possess the ability to bind with more metal ions due to their larger specific surface area. Additionally, their semiconductor physical properties enable the generation of reactive oxygen species (ROS). Therefore, CM NFs hold great potential for widespread application in antifungal products.</jats:p>
摘要:
In this study, thermal and calcium oxide (CaO) pretreatment were used as a strategy to improve the performance of the anaerobic digestion of food waste. Meanwhile, the carbon emissions among the two strategies were evaluated. The results showed that both the two strategies could effectively promote the solubilization of organic matter in food waste and improve the hydrolysis rate of anaerobic digestion, which resulted in an increase of the methane yield. The highest methane yield (284.4 mL/g VS) was obtained in the group pretreated with 1.0 g/L CaO, which was increased by 23.8% compared with the control group. After the pretreatment, the anaerobic digestion pathway changed from acetotrophic methanogenesis to the co-dominated methanogenesis process by hydrogentrophic and acetotrophic. Meanwhile, CaO pretreatment had a better performance on the carbon emission which was increased by 23.75% compared with the control group.
通讯机构:
[Wei, BM ] W;[Wang, HB ] H;Wuhan Polytech Univ, Sch Chem & Environm Engn, Wuhan, Hubei, Peoples R China.;Hubei Engn Univ, Coll Life Sci & Technol, Hubei Key Lab Qual Control Characterist Fruits & V, Xiaogan, Hubei, Peoples R China.
摘要:
A significant focus of carbon dot research is on enhancing the fluorescence emission performance of biomimetic carbon dots to improve their application value in practical analysis. In this study, fish scales were used as a precursor, and citric acid was introduced to improve the quantum yield of carbon dots. The results showed that under 350 nm excitation, citric acid-modified carbon dots (CDs-FS/CA) exhibited a maximum fluorescence emission of 411 nm, and the emission behavior was independent of the excitation wavelength, with a quantum yield of 35.5%. This high quantum yield could be attributed to the presence of citric acid and the participation of hydroxyapatite in fish scales. The CDs-FS/CA had a moderate degree of graphitization, smaller and more concentrated particle size distribution, and a high proportion of pyrrole N. They showed good fluorescence performance through the synergistic effect of surface state sp2 C and different N-doped surface states. A good linear relationship in the range of 0-50 mu mol L-1 was obtained using CDs-FS/CA for trace detection of quercetin, with a limit of detection of 3.8 nmol L-1, and good recovery in actual sample detection. These results offer a reference for enhancing the quantum yield of CDs obtained from alternative biomass sources and indicate the encouraging commercial feasibility of CDs derived from waste biomass for detecting trace amounts of quercetin. Through modification, this work significantly enhances the quantum yield of carbon dots derived from fish scales and applies them for trace detection of quercetin.