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 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
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.
文摘研究了Mn-W/TiO2用于NH3选择性催化还原NOx体系的催化反应性能,探索了不同温度条件下该催化剂对抗不同SO2浓度的抗毒性能。结果显示WO3能够增加活性酸中心的数量和酸性,是MnOx/TiO2非常有效的助催化剂。在气体体积空速(gaseous hourly space velocity,GHSV)为18900h-1时100～350℃范围内,Mn-W/TiO2催化剂还原NOx的转化率高达80.3%～99.6%,N2选择性达100%～98.7%。当反应气中有0.01%SO2和6%H2O时,120℃NOx转化率可维持在98.5%,当SO2浓度超过0.01%时,则需将反应温度升高到250℃以上才可消除其干扰,而当SO2浓度高达0.07%时,300℃下转化率可长期维持在99%,达到了商用V-W/TiO2催化剂的水平。对于NH3选择性还原NOx体系Mn-W/TiO2显示了极好的催化性能,是目前抗SO2毒性最强的催化剂之一。试验发现,低温条件下,SO2对Mn-W/TiO2催化剂的影响是可逆的,随着反应温度的提高,活性将自然恢复。
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.
