In this study,a step-scheme photocatalytic system comprising one-dimensional In_(2)O_(3)nanorods and two-dimensional ZnIn_(2)S_(4)nanosheets was developed for the catalytic photofixation of nitrogen.The effects of the...In this study,a step-scheme photocatalytic system comprising one-dimensional In_(2)O_(3)nanorods and two-dimensional ZnIn_(2)S_(4)nanosheets was developed for the catalytic photofixation of nitrogen.The effects of the combination of In_(2)O_(3)with ZnIn_(2)S_(4)on the crystallinity,microstructure,optical absorption,and charge transfer behavior of the In_(2)O_(3)/ZnIn_(2)S_(4)hybrid photocatalysts were investigated.Benefiting from the synergistic effects of the photogenerated vacancies and a step-scheme charge separation mechanism,the In_(2)O_(3)/ZnIn_(2)S_(4)hybrid photocatalyst exhibited significantly enhanced catalytic activity compared to those of bare In_(2)O_(3)and pure ZnIn_(2)S_(4),and an optimized 50 wt%In_(2)O_(3)/ZnIn_(2)S_(4)hybrid sample was found to exhibit superior catalytic activity for the photofixation of N2,fixing 18.1±0.77 mg·L-1 of ammonia after exposure to simulated sunlight for 2 h.Crucially,the results of trapping experiments and electron paramagnetic resonance investigation to identify the active species confirmed that the catalytic nitrogen photofixation performance was highly correlated with the presence of·CO_(2)-radicals rather than photogenerated electrons,especially when methanol was used as a hole scavenger.In summary,the reported In_(2)O_(3)/ZnIn_(2)S_(4)hybrid photocatalysts exhibit both stability and high activity for the photofixation of N_(2),making them promising catalysts for sunlight-driven artificial N_(2)fixation.展开更多
The reactive adsorption desulfurization of model gasoline was carried out on Ni/ZnO-HY adsorbent.The Ni/ZnO-HY adsorbent was characterized by N2adsorption-desorption test(BET),X-ray diffractometry(XRD),and temperature...The reactive adsorption desulfurization of model gasoline was carried out on Ni/ZnO-HY adsorbent.The Ni/ZnO-HY adsorbent was characterized by N2adsorption-desorption test(BET),X-ray diffractometry(XRD),and temperature-programmed reduction(TPR)analysis.The test results have demonstrated that HY-zeolite is a feasible support for Ni/ZnO components used in reactive adsorption desulfurization.The results of XRD and TPR analyses showed that most of nickel element was present as Ni2+species with only a small part existing as Ni3+species,and the Ni2+species had interactions with HY-zeolite.Under the conditions of this study,which specified a 50% ratio of HY-zeolite in the adsorbent,a Zn/Ni molar ratio of 10,and a reduction temperature of 400℃,the Ni/ZnO-HY adsorbent showed the best desulfurization performance.The sulfur capacity of Ni/ZnO-HY adsorbent could be recovered to 92.19% of the fresh one after being subjected to regeneration at 500℃,and could be maintained at 82.17% of the fresh one after 5 regeneration cycles.展开更多
ZnS:Mn2+ nanocrystals(NCs) with particle size from 1.9 nm to 3.2 nm are synthesized via chemical precipitation method with different [S2-]/[Zn2+] ratios.The size-dependent decay for Mn emission exhibits a double expon...ZnS:Mn2+ nanocrystals(NCs) with particle size from 1.9 nm to 3.2 nm are synthesized via chemical precipitation method with different [S2-]/[Zn2+] ratios.The size-dependent decay for Mn emission exhibits a double exponential behavior.And two lifetime values,in millisecond time domain,can both be shortened with size increasing,which is attributed to enhanced interaction between host and Mn2+ impurity.A molecular structure model is proposed to interpret the tendency of two lifetime components,which is correlated to the number of S vacancy(Vs) defects around Mn2+.展开更多
文摘In this study,a step-scheme photocatalytic system comprising one-dimensional In_(2)O_(3)nanorods and two-dimensional ZnIn_(2)S_(4)nanosheets was developed for the catalytic photofixation of nitrogen.The effects of the combination of In_(2)O_(3)with ZnIn_(2)S_(4)on the crystallinity,microstructure,optical absorption,and charge transfer behavior of the In_(2)O_(3)/ZnIn_(2)S_(4)hybrid photocatalysts were investigated.Benefiting from the synergistic effects of the photogenerated vacancies and a step-scheme charge separation mechanism,the In_(2)O_(3)/ZnIn_(2)S_(4)hybrid photocatalyst exhibited significantly enhanced catalytic activity compared to those of bare In_(2)O_(3)and pure ZnIn_(2)S_(4),and an optimized 50 wt%In_(2)O_(3)/ZnIn_(2)S_(4)hybrid sample was found to exhibit superior catalytic activity for the photofixation of N2,fixing 18.1±0.77 mg·L-1 of ammonia after exposure to simulated sunlight for 2 h.Crucially,the results of trapping experiments and electron paramagnetic resonance investigation to identify the active species confirmed that the catalytic nitrogen photofixation performance was highly correlated with the presence of·CO_(2)-radicals rather than photogenerated electrons,especially when methanol was used as a hole scavenger.In summary,the reported In_(2)O_(3)/ZnIn_(2)S_(4)hybrid photocatalysts exhibit both stability and high activity for the photofixation of N_(2),making them promising catalysts for sunlight-driven artificial N_(2)fixation.
基金financially supported by the National Natural Science Foundation of China(No.21276086)the Opening Project of State Key Laboratory of Chemical Engineering of East China University of Science and Technology(No.SKL-ChE-11C04)
文摘The reactive adsorption desulfurization of model gasoline was carried out on Ni/ZnO-HY adsorbent.The Ni/ZnO-HY adsorbent was characterized by N2adsorption-desorption test(BET),X-ray diffractometry(XRD),and temperature-programmed reduction(TPR)analysis.The test results have demonstrated that HY-zeolite is a feasible support for Ni/ZnO components used in reactive adsorption desulfurization.The results of XRD and TPR analyses showed that most of nickel element was present as Ni2+species with only a small part existing as Ni3+species,and the Ni2+species had interactions with HY-zeolite.Under the conditions of this study,which specified a 50% ratio of HY-zeolite in the adsorbent,a Zn/Ni molar ratio of 10,and a reduction temperature of 400℃,the Ni/ZnO-HY adsorbent showed the best desulfurization performance.The sulfur capacity of Ni/ZnO-HY adsorbent could be recovered to 92.19% of the fresh one after being subjected to regeneration at 500℃,and could be maintained at 82.17% of the fresh one after 5 regeneration cycles.
基金supported by the National Natural Science Foundation of China(Nos.60877029,10904109,60977035 and 60907021)the Natural Science Foundation of Tianjin(No.09JCYBJC01400)the Tianjin Key Subject for Materials Physics and Chemistry
文摘ZnS:Mn2+ nanocrystals(NCs) with particle size from 1.9 nm to 3.2 nm are synthesized via chemical precipitation method with different [S2-]/[Zn2+] ratios.The size-dependent decay for Mn emission exhibits a double exponential behavior.And two lifetime values,in millisecond time domain,can both be shortened with size increasing,which is attributed to enhanced interaction between host and Mn2+ impurity.A molecular structure model is proposed to interpret the tendency of two lifetime components,which is correlated to the number of S vacancy(Vs) defects around Mn2+.
