The steel industry produces many byproducts, requiring extensive land for storage and causing significant environmental contamination. Industrial effluents discharged into water bodies negatively impact both aquatic e...The steel industry produces many byproducts, requiring extensive land for storage and causing significant environmental contamination. Industrial effluents discharged into water bodies negatively impact both aquatic ecosystems and human health. To solve this problem, this study synthesized a composite of titanium dioxide (TiO2) and steel slag nanocomposites (SSNC) at a 1:2 mass ratio to create a robust photocatalyst for the treatment of synthetic wastewater. The efficacy of this catalyst in degrading various dye pollutants, including methylene blue (MB), was tested under simulated solar light conditions. Comprehensive analyses were conducted to assess the physical and chemical characteristics, crystalline structure, energy gap, and point of zero charge of the composite. The TiO2-SSNC composite catalyst exhibited excellent stability, with a point of zero charge at 8.342 and an energy gap of 2.4 eV. The degradation process conformed to pseudo-first-order kinetics. Optimization of operational parameters was achieved through the response surface methodology. Reusability tests demonstrated that the TiO2-SSNC composite catalyst effectively degraded up to 93.41% of MB in the suspended mode and 92.03% in the coated mode after five cycles. Additionally, the degradation efficiencies for various dyes were significant, highlighting the potential of the composite for broad applications in industrial wastewater treatment. This study also explored the degradation mechanisms and identified byproducts, establishing a pathway for contaminant breakdown. The cost-benefit analysis revealed a total cost of 0.842 8 USD per cubic meter for each treatment activity, indicating low operational and production costs. These findings underscore the promise of the TiO2-SSNC composite as a cost-effective and efficient alternative for wastewater purification.展开更多
Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolu...Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolution reaction(HER)by enhancing Volmer kinetics from rapid water dissociation and improving Tafel kinetics from efficient H*desorption.Atomic layer deposition of Ru with 50 process cycles results in a mixture of Ru SAs and 2.8-0.4 nm NPs present on TNT layers,and it emerges with the highest HER activity among all the electrodes synthesized.A detailed study of the Ti and Ru species using different high-resolution techniques confirmed the presence of Ti^(3+)states and the coexistence of Ru SAs and NPs.With insights from literature,the role of Ti^(3+),appropriate work functions of TNT layers and Ru,and the synergistic effect of Ru SAs and Ru NPs in improving the performance of alkaline HER were elaborated and justified.The aforementioned characteristics led to a remarkable performance by having 9mV onset potentials and 33 mV dec^(-1) of Tafel slopes and a higher turnover frequency of 1.72 H2 s^(-1) at 30 mV.Besides,a notable stability from 28 h staircase chronopotentiometric measurements for TNT@Ru surpasses TNT@Pt in comparison.展开更多
The selective cleavage of C-O and C-C is facing a challenge in the field of catalysis.In the present work,we studied the influence of doped Ni on the structure and electronic properties,as well as the selective C-O/C-...The selective cleavage of C-O and C-C is facing a challenge in the field of catalysis.In the present work,we studied the influence of doped Ni on the structure and electronic properties,as well as the selective C-O/C-C bond cleavages in the hydrodeoxygenation of palmitic acid over Ni-Mo_(2)C catalyst.The catalytic activity on Ni doped Mo_(2)C with TOF of 6.9×10^(3)h^(-1)is much superior to intrinsic Mo_(2)C catalyst,which is also higher than most noble metal catalysts.Structurally,the doped Ni raises the active particle dispersion and the coordination numbers of Mo species(Mo-C and Mo-O),improves the graphitization degree to promote the electron transfer,and increases the amount of Lewis and Br?nsted acid,which are responsible for the excellent hydrodeoxygenation performance.The Ni promotes simultaneously C-O and C-C bonds cleavage to produce pentadecane and hexadecane owing to the increase of electron-rich Mo sites after Ni doping.These findings contribute to the understanding of the nature of Ni-doped Mo_(2)C on the roles as catalytic active sites for C-O and C-C bonds cleavage.展开更多
The problem of water depollution is gaining importance, especially as regulatory standards concerning drinking water are increasingly strict. The different industries (textile industries) generate chemically stable po...The problem of water depollution is gaining importance, especially as regulatory standards concerning drinking water are increasingly strict. The different industries (textile industries) generate chemically stable pollutants such as methyl orange which make their degradation difficult. It is therefore necessary to find new, more effective techniques for the treatment of these discharges. Among the different solutions proposed to deal with this problem, we find advanced oxidation processes (POAs) which are clean and promising technologies in the field of wastewater depollution. In this regard, heterogeneous photocatalysis was used in an aqueous suspension of titanium oxide (TiO2) using a ultraviolet (UV) lamp as artificial radiation. The objective of this work is to study the influence of some operating parameters such as: the catalyst mass, the initial pollutant concentration, the volume of the solution and the pH of the solution, were examined. The results obtained showed that this photocatalyst made it possible to degrade 99.85% of the initial concentration of methyl orange (10 ppm), after 240 min of irradiation with an optimal mass of 0.50 g of TiO2 for a volume of 200 mL of methyl orange solution at pH = 3.0.展开更多
The low efficiency of photogenerated carrier separation,and the poor adsorption and activation ability of CO_(2)on the surface of photocatalyst were the key problems to limit the efficiency of photocatalytic CO_(2)red...The low efficiency of photogenerated carrier separation,and the poor adsorption and activation ability of CO_(2)on the surface of photocatalyst were the key problems to limit the efficiency of photocatalytic CO_(2)reduction.Hence,maximally accelerating the immigration of photogenerated charges d increasing the number of active sites are critical points to boost the overall performance of photocatalytic CO_(2)reduction.However,it is still huge challenge.In this work,the Ni-doped ultrathin Bi_(4)O_(5)Br_(2)nanosheets,which was successfully prepared by hydrothermal and ultrasonic chemical stripping methods,exhibited efficient photocatalytic conversion of CO_(2)to CO.The results of experiments and theoretical calculations indicated that the doped Ni^(2+)significantly increased the crystal dipole moment of Bi_(4)O_(5)Br_(2)in y direction(from 0 to 0.096 e?),which enhanced the polarized electric field strength inside Bi_(4)O_(5)Br_(2),and further promoted the immigration of photogenerated carriers.Meanwhile,the ultrathin structure and doped Ni^(2+)synergistically increased the number of active sites,thereby promoting the adsorption and activation of CO_(2)molecules,as evidenced by experimental and theoretical results collectively.As result,The CO yield was as high as 26.57μmol g–1 h–1 for the prepared Ni-doped ultrathin Bi_(4)O_(5)Br_(2)nanosheets under full spectrum light irradiation,which was 9.48 times that of Bi_(4)O_(5)Br_(2).Therefore,it is of great scientific significance in this study to explore strategies to promote the separation of photogenerated carriers and enhance the adsorption and activation ability of CO_(2)on the surface.展开更多
基金supported by the Department of Chemical and Petrochemical Engineering,Egypt-Japan University of Science and Technology.
文摘The steel industry produces many byproducts, requiring extensive land for storage and causing significant environmental contamination. Industrial effluents discharged into water bodies negatively impact both aquatic ecosystems and human health. To solve this problem, this study synthesized a composite of titanium dioxide (TiO2) and steel slag nanocomposites (SSNC) at a 1:2 mass ratio to create a robust photocatalyst for the treatment of synthetic wastewater. The efficacy of this catalyst in degrading various dye pollutants, including methylene blue (MB), was tested under simulated solar light conditions. Comprehensive analyses were conducted to assess the physical and chemical characteristics, crystalline structure, energy gap, and point of zero charge of the composite. The TiO2-SSNC composite catalyst exhibited excellent stability, with a point of zero charge at 8.342 and an energy gap of 2.4 eV. The degradation process conformed to pseudo-first-order kinetics. Optimization of operational parameters was achieved through the response surface methodology. Reusability tests demonstrated that the TiO2-SSNC composite catalyst effectively degraded up to 93.41% of MB in the suspended mode and 92.03% in the coated mode after five cycles. Additionally, the degradation efficiencies for various dyes were significant, highlighting the potential of the composite for broad applications in industrial wastewater treatment. This study also explored the degradation mechanisms and identified byproducts, establishing a pathway for contaminant breakdown. The cost-benefit analysis revealed a total cost of 0.842 8 USD per cubic meter for each treatment activity, indicating low operational and production costs. These findings underscore the promise of the TiO2-SSNC composite as a cost-effective and efficient alternative for wastewater purification.
基金support from the European Union Horizon 2020 program(project HERMES,nr.952184)the Ministry of Education,Youth and Sports of the Czech Republic for supporting CEMNAT(LM2023037)+1 种基金Czech-NanoLab(LM2023051)infrastructures for providing ALD,SEM,EDX,XPS,TEM,and XRDCzech Science Foundation(project 23-08019X,EXPRO).
文摘Synergistic interplays involving multiple active centers originating from TiO2 nanotube layers(TNT)and ruthenium(Ru)species comprising of both single atoms(SAs)and nanoparticles(NPs)augment the alkaline hydrogen evolution reaction(HER)by enhancing Volmer kinetics from rapid water dissociation and improving Tafel kinetics from efficient H*desorption.Atomic layer deposition of Ru with 50 process cycles results in a mixture of Ru SAs and 2.8-0.4 nm NPs present on TNT layers,and it emerges with the highest HER activity among all the electrodes synthesized.A detailed study of the Ti and Ru species using different high-resolution techniques confirmed the presence of Ti^(3+)states and the coexistence of Ru SAs and NPs.With insights from literature,the role of Ti^(3+),appropriate work functions of TNT layers and Ru,and the synergistic effect of Ru SAs and Ru NPs in improving the performance of alkaline HER were elaborated and justified.The aforementioned characteristics led to a remarkable performance by having 9mV onset potentials and 33 mV dec^(-1) of Tafel slopes and a higher turnover frequency of 1.72 H2 s^(-1) at 30 mV.Besides,a notable stability from 28 h staircase chronopotentiometric measurements for TNT@Ru surpasses TNT@Pt in comparison.
基金financially supported by the National Natural Science Foundation of China(21972099)the Application Foundation Program of Sichuan Province(2021YJ0305)+1 种基金the 111 project(B17030).Shanghai Synchrotron Radiation Facility(SSRF)for XAS experiments and the support by the project from NPL of CAEP(2019BB08)。
文摘The selective cleavage of C-O and C-C is facing a challenge in the field of catalysis.In the present work,we studied the influence of doped Ni on the structure and electronic properties,as well as the selective C-O/C-C bond cleavages in the hydrodeoxygenation of palmitic acid over Ni-Mo_(2)C catalyst.The catalytic activity on Ni doped Mo_(2)C with TOF of 6.9×10^(3)h^(-1)is much superior to intrinsic Mo_(2)C catalyst,which is also higher than most noble metal catalysts.Structurally,the doped Ni raises the active particle dispersion and the coordination numbers of Mo species(Mo-C and Mo-O),improves the graphitization degree to promote the electron transfer,and increases the amount of Lewis and Br?nsted acid,which are responsible for the excellent hydrodeoxygenation performance.The Ni promotes simultaneously C-O and C-C bonds cleavage to produce pentadecane and hexadecane owing to the increase of electron-rich Mo sites after Ni doping.These findings contribute to the understanding of the nature of Ni-doped Mo_(2)C on the roles as catalytic active sites for C-O and C-C bonds cleavage.
文摘The problem of water depollution is gaining importance, especially as regulatory standards concerning drinking water are increasingly strict. The different industries (textile industries) generate chemically stable pollutants such as methyl orange which make their degradation difficult. It is therefore necessary to find new, more effective techniques for the treatment of these discharges. Among the different solutions proposed to deal with this problem, we find advanced oxidation processes (POAs) which are clean and promising technologies in the field of wastewater depollution. In this regard, heterogeneous photocatalysis was used in an aqueous suspension of titanium oxide (TiO2) using a ultraviolet (UV) lamp as artificial radiation. The objective of this work is to study the influence of some operating parameters such as: the catalyst mass, the initial pollutant concentration, the volume of the solution and the pH of the solution, were examined. The results obtained showed that this photocatalyst made it possible to degrade 99.85% of the initial concentration of methyl orange (10 ppm), after 240 min of irradiation with an optimal mass of 0.50 g of TiO2 for a volume of 200 mL of methyl orange solution at pH = 3.0.
文摘The low efficiency of photogenerated carrier separation,and the poor adsorption and activation ability of CO_(2)on the surface of photocatalyst were the key problems to limit the efficiency of photocatalytic CO_(2)reduction.Hence,maximally accelerating the immigration of photogenerated charges d increasing the number of active sites are critical points to boost the overall performance of photocatalytic CO_(2)reduction.However,it is still huge challenge.In this work,the Ni-doped ultrathin Bi_(4)O_(5)Br_(2)nanosheets,which was successfully prepared by hydrothermal and ultrasonic chemical stripping methods,exhibited efficient photocatalytic conversion of CO_(2)to CO.The results of experiments and theoretical calculations indicated that the doped Ni^(2+)significantly increased the crystal dipole moment of Bi_(4)O_(5)Br_(2)in y direction(from 0 to 0.096 e?),which enhanced the polarized electric field strength inside Bi_(4)O_(5)Br_(2),and further promoted the immigration of photogenerated carriers.Meanwhile,the ultrathin structure and doped Ni^(2+)synergistically increased the number of active sites,thereby promoting the adsorption and activation of CO_(2)molecules,as evidenced by experimental and theoretical results collectively.As result,The CO yield was as high as 26.57μmol g–1 h–1 for the prepared Ni-doped ultrathin Bi_(4)O_(5)Br_(2)nanosheets under full spectrum light irradiation,which was 9.48 times that of Bi_(4)O_(5)Br_(2).Therefore,it is of great scientific significance in this study to explore strategies to promote the separation of photogenerated carriers and enhance the adsorption and activation ability of CO_(2)on the surface.
