Dispersion of MoO3, NiO, ZnO on rutile TiO2 with low specific surface area wasstudied with Mercury Porosimeter, SEM, XPS and Ammonia Extraction method. The dispersionthresholds of MoO3, NiO, ZnO on three rutile TiO2 c...Dispersion of MoO3, NiO, ZnO on rutile TiO2 with low specific surface area wasstudied with Mercury Porosimeter, SEM, XPS and Ammonia Extraction method. The dispersionthresholds of MoO3, NiO, ZnO on three rutile TiO2 carriers were obtained with XPS, and com-pared with those on anatase TiO2 with high specific surf are area. Ammonia Extraction methodwas used to identify the surface oxide species interarting with support surface in different strengthand it was found that the proportions of oxides that can not be extrarted by ammonia extractionare different for MoO3, NiO and ZnO which are supported on rutile TiO2.展开更多
ZnO,NiO and ZnO@NiO nanocrystals were successfully synthesized and characterized by FTIR,XRD and SEM methods.The average particles sizes of ZnO,NiO and ZnO@NiO were32,50and48nm,respectively.The nanocrystals were exami...ZnO,NiO and ZnO@NiO nanocrystals were successfully synthesized and characterized by FTIR,XRD and SEM methods.The average particles sizes of ZnO,NiO and ZnO@NiO were32,50and48nm,respectively.The nanocrystals were examined assensors for cyanide removal.The cyanide sensing test revealed that,compared with the pure ZnO,NiO,the ZnO@NiO nanocrystalsexhibited highly improved sensing performances.The ZnO@NiO nano crystals were found to have better capacity for iron cyanidethan sodium cyanide.The effects of significant parameters such as contact time,pH(2-12),nanocrystal dose(0.02-0.4g)andcyanide concentration(5-50mg/L)on the removal of cyanide by nanocrystals were explored.At an optimum pH<5,over90%removal of20mg/L cyanide was obtained for nanocrystal dose of0.2g after30min contact time for iron cyanide by ZnO@NiOnano crystals.Cyanide removal was followed by pseudo second order kinetic model for ZnO@NiO nano crystals(k2=4.66×10-2andR2=0.999).The values of standard entralpy change of7.87kJ/mol and standard free energy change of-18.62kJ/mol at298K suggestthe adsorption of cyanide on nanocrystals is an endothermic and spontaneous process.ZnO@NiO nanocrystal is an efficient sensorfor removal of cyanide from water and wastewater.展开更多
ZnO/Fe_(2)O_(3) nanorod arrays(NRs)and ZnO/NiO nanotube arrays(NTs)are synthesized on Si substrates by using a facile two-step growth method.The absorption spectrum of the ZnO/Fe_(2)O_(3) NRs shows significant absorpt...ZnO/Fe_(2)O_(3) nanorod arrays(NRs)and ZnO/NiO nanotube arrays(NTs)are synthesized on Si substrates by using a facile two-step growth method.The absorption spectrum of the ZnO/Fe_(2)O_(3) NRs shows significant absorption in the visible light region.Their photocatalytic properties are evaluated by the degradation of methylene blue(MB).It is found that the ZnO/Fe_(2)O_(3) NRs display higher photocatalytic activity than the ZnO/NiO nanotube arrays under UV-vis light irradiation.This is most likely attributed to an effective separation of photoelectrons and holes.展开更多
文摘Dispersion of MoO3, NiO, ZnO on rutile TiO2 with low specific surface area wasstudied with Mercury Porosimeter, SEM, XPS and Ammonia Extraction method. The dispersionthresholds of MoO3, NiO, ZnO on three rutile TiO2 carriers were obtained with XPS, and com-pared with those on anatase TiO2 with high specific surf are area. Ammonia Extraction methodwas used to identify the surface oxide species interarting with support surface in different strengthand it was found that the proportions of oxides that can not be extrarted by ammonia extractionare different for MoO3, NiO and ZnO which are supported on rutile TiO2.
基金financial support from the Research Council of Islamic Azad University of Yazd
文摘ZnO,NiO and ZnO@NiO nanocrystals were successfully synthesized and characterized by FTIR,XRD and SEM methods.The average particles sizes of ZnO,NiO and ZnO@NiO were32,50and48nm,respectively.The nanocrystals were examined assensors for cyanide removal.The cyanide sensing test revealed that,compared with the pure ZnO,NiO,the ZnO@NiO nanocrystalsexhibited highly improved sensing performances.The ZnO@NiO nano crystals were found to have better capacity for iron cyanidethan sodium cyanide.The effects of significant parameters such as contact time,pH(2-12),nanocrystal dose(0.02-0.4g)andcyanide concentration(5-50mg/L)on the removal of cyanide by nanocrystals were explored.At an optimum pH<5,over90%removal of20mg/L cyanide was obtained for nanocrystal dose of0.2g after30min contact time for iron cyanide by ZnO@NiOnano crystals.Cyanide removal was followed by pseudo second order kinetic model for ZnO@NiO nano crystals(k2=4.66×10-2andR2=0.999).The values of standard entralpy change of7.87kJ/mol and standard free energy change of-18.62kJ/mol at298K suggestthe adsorption of cyanide on nanocrystals is an endothermic and spontaneous process.ZnO@NiO nanocrystal is an efficient sensorfor removal of cyanide from water and wastewater.
基金Supported by the National Basic Research Program of China under Grant No 2007CB613302the National Natural Science Foundation of China under Grant No 50972002.
文摘ZnO/Fe_(2)O_(3) nanorod arrays(NRs)and ZnO/NiO nanotube arrays(NTs)are synthesized on Si substrates by using a facile two-step growth method.The absorption spectrum of the ZnO/Fe_(2)O_(3) NRs shows significant absorption in the visible light region.Their photocatalytic properties are evaluated by the degradation of methylene blue(MB).It is found that the ZnO/Fe_(2)O_(3) NRs display higher photocatalytic activity than the ZnO/NiO nanotube arrays under UV-vis light irradiation.This is most likely attributed to an effective separation of photoelectrons and holes.
