The structural and optical characterization of cadmium-doped zinc oxide nanoparticles synthesized by precipitation method was studied.X-ray diffraction study confirmed the substitution of cadmium dopant without distur...The structural and optical characterization of cadmium-doped zinc oxide nanoparticles synthesized by precipitation method was studied.X-ray diffraction study confirmed the substitution of cadmium dopant without disturbing the basic wurtzite structure of zinc oxide.The average crystalline size,lattice constants and unit cell volume also increased up to4%of cadmium doping.Energy gaps of the samples were determined from the ultraviolet?visible absorption spectrum as well as Tauc’s plot which infers that the energy gap decreases with the increase of cadmium content.Fourier transformation infrared spectrum confirms the cadmium dopant through peak shifting from485to563cm?1.Photoluminescence spectrum also defines the cadmium dopant by intensity increase.The broad Raman peak at437cm?1indicates that the wurtzite structure of zinc oxide is weakened by5%cadmium doping.Field emission scanning electron microscope study also confirms the existence of particles in nanometer size and it indentifies the microstructure transformation from nanoparticles to jasmine flower-like structure on5%cadmium doping.展开更多
To achieve efficient photocatalytic H_(2) generation from water using earth-abundant and cost-effective materials,a simple synthesis method for carbon-doped CdS particles wrapped with graphene(C-doped CdS@G)is reporte...To achieve efficient photocatalytic H_(2) generation from water using earth-abundant and cost-effective materials,a simple synthesis method for carbon-doped CdS particles wrapped with graphene(C-doped CdS@G)is reported.The doping effect and the application of graphene as cocatalyst for CdS is studied for photocatalytic H_(2) generation.The most active sample consists of CdS and graphene(CdS-0.15G)exhibits promising photocatalytic activity,producing 3.12 mmol g^-(1) h^-(1) of H_(2) under simulated solar light which is^4.6 times superior than pure CdS nanoparticles giving an apparent quantum efficiency(AQY)of 11.7%.The enhanced photocatalytic activity for H_(2) generation is associated to the narrowing of the bandgap,enhanced light absorption,fast interfacial charge transfer,and higher carrier density(N_(D))in C-doped CdS@G samples.This is achieved by C doping in CdS nanoparticles and the formation of a graphene shell over the C-doped CdS nanoparticles.After stability test,the spent catalysts sample was also characterized to investigate the nanostructure.展开更多
文摘The structural and optical characterization of cadmium-doped zinc oxide nanoparticles synthesized by precipitation method was studied.X-ray diffraction study confirmed the substitution of cadmium dopant without disturbing the basic wurtzite structure of zinc oxide.The average crystalline size,lattice constants and unit cell volume also increased up to4%of cadmium doping.Energy gaps of the samples were determined from the ultraviolet?visible absorption spectrum as well as Tauc’s plot which infers that the energy gap decreases with the increase of cadmium content.Fourier transformation infrared spectrum confirms the cadmium dopant through peak shifting from485to563cm?1.Photoluminescence spectrum also defines the cadmium dopant by intensity increase.The broad Raman peak at437cm?1indicates that the wurtzite structure of zinc oxide is weakened by5%cadmium doping.Field emission scanning electron microscope study also confirms the existence of particles in nanometer size and it indentifies the microstructure transformation from nanoparticles to jasmine flower-like structure on5%cadmium doping.
基金support from the Research Council of Norway provided by the Norwegian Center for Transmission Electron Microscopy,NORTEM(197405/F50)NTNU NanoLab(grant number 245963)which have provided the characterization toolsthe strategic funding support provided by Department of Chemical Engineering,NTNU,Trondheim,Norway.
文摘To achieve efficient photocatalytic H_(2) generation from water using earth-abundant and cost-effective materials,a simple synthesis method for carbon-doped CdS particles wrapped with graphene(C-doped CdS@G)is reported.The doping effect and the application of graphene as cocatalyst for CdS is studied for photocatalytic H_(2) generation.The most active sample consists of CdS and graphene(CdS-0.15G)exhibits promising photocatalytic activity,producing 3.12 mmol g^-(1) h^-(1) of H_(2) under simulated solar light which is^4.6 times superior than pure CdS nanoparticles giving an apparent quantum efficiency(AQY)of 11.7%.The enhanced photocatalytic activity for H_(2) generation is associated to the narrowing of the bandgap,enhanced light absorption,fast interfacial charge transfer,and higher carrier density(N_(D))in C-doped CdS@G samples.This is achieved by C doping in CdS nanoparticles and the formation of a graphene shell over the C-doped CdS nanoparticles.After stability test,the spent catalysts sample was also characterized to investigate the nanostructure.
