Mesocrystalline TiO2/sepiolite （TiS） composites with the function of adsorption and degradation of liquid organic pollutants were successfully fabricated via a facile and low-cost solvothermal reaction. The prepared...Mesocrystalline TiO2/sepiolite （TiS） composites with the function of adsorption and degradation of liquid organic pollutants were successfully fabricated via a facile and low-cost solvothermal reaction. The prepared TiS composites were characterized by FESEM, HRTEM, XRD, XPS, N2 adsorption-desorption, UV-vis DRS, and EPR. Results revealed the homogeneous dispersion of highly reactive TiO2 mesocrystals on the sepiolite nanofibers. Thereinto each single-crystal-like TiO2 mesocrystal comprised many [001]-oriented anatase nanoparticles about 10-20 nm in diameter. The photocatalytic activity was further evaluated by the degradation of anionic dye （methyl orange） and cationic dye （methylene blue） under the UV-vis light （350≤λ≤780 nm） irradiation. By selecting appropriate experimental conditions, we can easily manipulate the photocatalytic performance of TiS composites. The optimal TiS catalyst （the sepiolite content of 28.5 wt.%, and the reaction time of 24 h） could efficiently degrade methyl orange to 90.7% after 70 min, or methylene blue to 97.8% after 50 min, under UV-vis light irradiation. These results can be attributed to their synergistic effect of high crystallinity, large specific surface area, abundant hydroxyl radicals, and effective photogenerated charge separation.展开更多
The performance of Mn-TiO2/sepiolite photocatalysts prepared by the solgel method and calcinated at different temperatures was studied in the photocatalytic degradation of direct fast emerald green dye under visible l...The performance of Mn-TiO2/sepiolite photocatalysts prepared by the solgel method and calcinated at different temperatures was studied in the photocatalytic degradation of direct fast emerald green dye under visible light irradiation,and a series of analytical techniques such as XRD,SEM,FTIR,TG-DSC,XPS,UV-vis-DRS and Raman spectroscopy were used to characterize the morphology,structure and optical properties of the photocatalysts.It is found that the anatase TiO2 was formed in all photocatalysts.Mn4+might incorporate into the lattice structure of TiO2 and partially replace Ti4+,thus causing the defects in the crystal structure and the broadening of the spectral response range of TiO2.At the same time,TiO2 particles were dispersed on the surface of the sepiolite,which immobilized TiO2 particles with sepiolite via the bond of Ti-O-Si.Mn-TiO2/sepiolite calcined at 400°C exhibits the highest photocatalytic activity and the degradation rate of direct fast emerald green is up to 98.13%.Meanwhile,it also shows good stability and universality.展开更多
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
A novel ternary sepiolite/Cu_2O/Cu(SCC) nanocomposite was successfully synthesized by a facile one-pot method. The Cu_2O/Cu nanoparticles in the SCC nanocomposite are well dispersed on the sepiolite surface. It exhibi...A novel ternary sepiolite/Cu_2O/Cu(SCC) nanocomposite was successfully synthesized by a facile one-pot method. The Cu_2O/Cu nanoparticles in the SCC nanocomposite are well dispersed on the sepiolite surface. It exhibited enhanced photocatalytic performance in the degradation of congo red(CR), remarkably superior to that of Cu_2O or Cu_2O/Cu nanoparticles. Elemental copper in the SCC serves as a good electron acceptor to promote the transfer of photo-generated electrons in Cu_2O and suppress the recombination of the photo-generated electrons and holes of the composite. The enhanced photocatalytic efficiency is attributed to the synergistic effect of sepiolite and Cu_2O/Cu. This type of SCC nanocomposites is a promising candidate as photocatalytic material for environmental protection.展开更多
文摘Mesocrystalline TiO2/sepiolite （TiS） composites with the function of adsorption and degradation of liquid organic pollutants were successfully fabricated via a facile and low-cost solvothermal reaction. The prepared TiS composites were characterized by FESEM, HRTEM, XRD, XPS, N2 adsorption-desorption, UV-vis DRS, and EPR. Results revealed the homogeneous dispersion of highly reactive TiO2 mesocrystals on the sepiolite nanofibers. Thereinto each single-crystal-like TiO2 mesocrystal comprised many [001]-oriented anatase nanoparticles about 10-20 nm in diameter. The photocatalytic activity was further evaluated by the degradation of anionic dye （methyl orange） and cationic dye （methylene blue） under the UV-vis light （350≤λ≤780 nm） irradiation. By selecting appropriate experimental conditions, we can easily manipulate the photocatalytic performance of TiS composites. The optimal TiS catalyst （the sepiolite content of 28.5 wt.%, and the reaction time of 24 h） could efficiently degrade methyl orange to 90.7% after 70 min, or methylene blue to 97.8% after 50 min, under UV-vis light irradiation. These results can be attributed to their synergistic effect of high crystallinity, large specific surface area, abundant hydroxyl radicals, and effective photogenerated charge separation.
基金We gratefully acknowledge the financial support from the National Natural Science Foundation of China(Grant No.21406184)the Foundation of Youth Science and Technology Innovation Team of Sichuan Province(Grant No.2015TD0007).
文摘The performance of Mn-TiO2/sepiolite photocatalysts prepared by the solgel method and calcinated at different temperatures was studied in the photocatalytic degradation of direct fast emerald green dye under visible light irradiation,and a series of analytical techniques such as XRD,SEM,FTIR,TG-DSC,XPS,UV-vis-DRS and Raman spectroscopy were used to characterize the morphology,structure and optical properties of the photocatalysts.It is found that the anatase TiO2 was formed in all photocatalysts.Mn4+might incorporate into the lattice structure of TiO2 and partially replace Ti4+,thus causing the defects in the crystal structure and the broadening of the spectral response range of TiO2.At the same time,TiO2 particles were dispersed on the surface of the sepiolite,which immobilized TiO2 particles with sepiolite via the bond of Ti-O-Si.Mn-TiO2/sepiolite calcined at 400°C exhibits the highest photocatalytic activity and the degradation rate of direct fast emerald green is up to 98.13%.Meanwhile,it also shows good stability and universality.
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supported by the National Natural Science Foundation of China (Grant No. 51372238)the CNPC-CAS Strategic Cooperation Research Program (2015A-4812)the Provincial Teaching Research Project of Anhui Province (2014jyxm010)
文摘A novel ternary sepiolite/Cu_2O/Cu(SCC) nanocomposite was successfully synthesized by a facile one-pot method. The Cu_2O/Cu nanoparticles in the SCC nanocomposite are well dispersed on the sepiolite surface. It exhibited enhanced photocatalytic performance in the degradation of congo red(CR), remarkably superior to that of Cu_2O or Cu_2O/Cu nanoparticles. Elemental copper in the SCC serves as a good electron acceptor to promote the transfer of photo-generated electrons in Cu_2O and suppress the recombination of the photo-generated electrons and holes of the composite. The enhanced photocatalytic efficiency is attributed to the synergistic effect of sepiolite and Cu_2O/Cu. This type of SCC nanocomposites is a promising candidate as photocatalytic material for environmental protection.
