The electrode/electrlyte interface is of great signifance to photoelectrochemical(PEC)water oxidation as the reaction mainly occur here.Herein,we focus on the effect of supercapactance of the electrode/electrlyte inte...The electrode/electrlyte interface is of great signifance to photoelectrochemical(PEC)water oxidation as the reaction mainly occur here.Herein,we focus on the effect of supercapactance of the electrode/electrlyte interface on the performance of PEC.It is discovered that the supercapacitor on the interface is crucial because it links the charge transport and solution ion adsorption on its two sides.In this study,we demonstrate an approach to promote the performance of TiO_(2)nanowire array(TiO_(2)NWs)photoanode in photoelectrochemical cells(PECs)by increasing its supercapacitance.A 2−5 nm carbon layer was coated and the interface supercapacitance increases by about 150 times.This enhances the separation rate of electron-hole pairs by collecting more holes.Meanwhile,it also promotes the water oxidation rate by adsorbing more OH−on its surface.As a result,the photocurrent density of C-TiO_(2)NWs was about 8 times higher than that of its carbon-free counterpart.This approach of increasing the supercapacitance of photoanodes would be attractive for enhancement of the efficiency of PECs and this work demonstrate the importance of supercapacitance of the interface for PECs.展开更多
Photoelectrochemical(PEC)water splitting is a promising technology to use solar energy.However,current metal oxides photoanode face the problem of sluggish water oxidation kinetic.In this study,we propose that the slu...Photoelectrochemical(PEC)water splitting is a promising technology to use solar energy.However,current metal oxides photoanode face the problem of sluggish water oxidation kinetic.In this study,we propose that the sluggish water oxidation process will cause slow mass transfer efficiency,which are rarely considered previously,especially at large bias and strong illumination.Mass transfer refers to the migration of reactants(like H_(2)O and OH^(-))to the photoanode surface,reaction with holes and diffusion of products(like radical and O^(2))to the bulk of the electrode.If the migration and diffusion are not fast enough,the mass transfer will inhibit the increase of PEC activity.This problem will be more apparent for nanorod arrays(NRAs),where the space among the NRAs is related narrow.Herein,we solve this problem by decorating the surface of the photoanode by NiO clusters with Ni3+state as water oxidation cocatalysts.This work studies the PEC process from the viewpoint of mass transfer and firstly demonstrates that mass transfer in NRAs structure can be promoted by using Ni-based water oxidation cocatalyst.展开更多
基金supported by the National Natural Science Foundation of China(No.51902357)the Natural Science Foundation of Guangdong Province,China(No.2019A1515012143)+1 种基金the Start-up Funds for High-Level Talents of Sun Yat-sen University(No.38000-18841209)the Fundamental Research Funds for the Central Universities(No.191gpy153).
文摘The electrode/electrlyte interface is of great signifance to photoelectrochemical(PEC)water oxidation as the reaction mainly occur here.Herein,we focus on the effect of supercapactance of the electrode/electrlyte interface on the performance of PEC.It is discovered that the supercapacitor on the interface is crucial because it links the charge transport and solution ion adsorption on its two sides.In this study,we demonstrate an approach to promote the performance of TiO_(2)nanowire array(TiO_(2)NWs)photoanode in photoelectrochemical cells(PECs)by increasing its supercapacitance.A 2−5 nm carbon layer was coated and the interface supercapacitance increases by about 150 times.This enhances the separation rate of electron-hole pairs by collecting more holes.Meanwhile,it also promotes the water oxidation rate by adsorbing more OH−on its surface.As a result,the photocurrent density of C-TiO_(2)NWs was about 8 times higher than that of its carbon-free counterpart.This approach of increasing the supercapacitance of photoanodes would be attractive for enhancement of the efficiency of PECs and this work demonstrate the importance of supercapacitance of the interface for PECs.
基金supported by the Guangdong Basic and Applied Basic Research Foundation(No.2019B1515120058)the National Natural Science Foundation of China(No.51902357)+2 种基金the Natural Science Foundation of Guangdong Province,China(No.2019A1515012143)the Start-up Funds for High-Level Talents of Sun Yat-sen University(No.38000-18841209)the Fundamental Research Funds for the Central Universities(No.19lgpy153)。
文摘Photoelectrochemical(PEC)water splitting is a promising technology to use solar energy.However,current metal oxides photoanode face the problem of sluggish water oxidation kinetic.In this study,we propose that the sluggish water oxidation process will cause slow mass transfer efficiency,which are rarely considered previously,especially at large bias and strong illumination.Mass transfer refers to the migration of reactants(like H_(2)O and OH^(-))to the photoanode surface,reaction with holes and diffusion of products(like radical and O^(2))to the bulk of the electrode.If the migration and diffusion are not fast enough,the mass transfer will inhibit the increase of PEC activity.This problem will be more apparent for nanorod arrays(NRAs),where the space among the NRAs is related narrow.Herein,we solve this problem by decorating the surface of the photoanode by NiO clusters with Ni3+state as water oxidation cocatalysts.This work studies the PEC process from the viewpoint of mass transfer and firstly demonstrates that mass transfer in NRAs structure can be promoted by using Ni-based water oxidation cocatalyst.
