There have been reports about Fe ions boosting oxygen evolution reaction(OER)activity of Ni-based catalysts in alkaline conditions,while the origin and reason for the enhancement remains elusive.Herein,we attempt to i...There have been reports about Fe ions boosting oxygen evolution reaction(OER)activity of Ni-based catalysts in alkaline conditions,while the origin and reason for the enhancement remains elusive.Herein,we attempt to identify the activity improvement and discover that Ni sites act as a host to attract Fe(Ⅲ)to form Fe(Ni)(Ⅲ)binary centres,which serve as the dynamic sites to promote OER activity and stability by cyclical formation of intermediates(Fe(Ⅲ)→Fe(Ni)(Ⅲ)→Fe(Ni)-OH→Fe(Ni)-O→Fe(Ni)OOH→Fe(Ⅲ))at the electrode/electrolyte interface to emit O_(2).Additionally,some ions(Co(Ⅱ),Ni(Ⅱ),and Cr(Ⅲ))can also be the active sites to catalyze the OER process on a variety of electrodes.The Fe(Ⅲ)-catalyzed overall water-splitting electrolyzer comprising bare Ni foam as the anode and Pt/Ni-Mo as the cathode demonstrates robust stability for 1600 h at 1000 mA cm^(-2)@~1.75 V.The results provide insights into the ioncatalyzed effects boosting OER performance.展开更多
Bi VO_(4)is a promising semiconducting photoanode for photoelectrochemical(PEC)water splitting due to its suitable bandgap.However,the dissolution of V^(5+)and sluggish reaction kinetics at the surface in the oxygen e...Bi VO_(4)is a promising semiconducting photoanode for photoelectrochemical(PEC)water splitting due to its suitable bandgap.However,the dissolution of V^(5+)and sluggish reaction kinetics at the surface in the oxygen evolution reaction(OER)limit its applications.Herein,we report a convenient strategy to change the microenvironment by adding Fe(Ⅲ)into the electrolyte.During the PEC process,Fe(Ⅲ)ions not only improve the current density,but also show excellent stability toward Bi VO_(4).Consequently,the current increases by more than 1.7 times compared to that without Fe(Ⅲ).Photoelectrochemical,morphological,and structural characterizations reveal that the FeOOH co-catalyst produced in situ on the Bi VO_(4)photoanode by cyclical formation of the intermediates at the electrode/electrolyte interface during OER accelerates the OER kinetics and prevents photo-corrosion by suppressing the dissolution of V^(5+).The results reveal a new strategy for the multifunctional modification of photoanodes for efficient solar conversion.展开更多
基金financially supported by the 2022 Special Fund Project for Science and Technology Innovation Strategy of Guangdong Province(STKJ202209077 and STKJ202209083)the Guangdong Province Universities and Colleges Pearl River Scholar Funded Scheme 2019(GDUPS2019)the City University of Hong Kong Strategic Research Grant(SRG)(7005505)。
文摘There have been reports about Fe ions boosting oxygen evolution reaction(OER)activity of Ni-based catalysts in alkaline conditions,while the origin and reason for the enhancement remains elusive.Herein,we attempt to identify the activity improvement and discover that Ni sites act as a host to attract Fe(Ⅲ)to form Fe(Ni)(Ⅲ)binary centres,which serve as the dynamic sites to promote OER activity and stability by cyclical formation of intermediates(Fe(Ⅲ)→Fe(Ni)(Ⅲ)→Fe(Ni)-OH→Fe(Ni)-O→Fe(Ni)OOH→Fe(Ⅲ))at the electrode/electrolyte interface to emit O_(2).Additionally,some ions(Co(Ⅱ),Ni(Ⅱ),and Cr(Ⅲ))can also be the active sites to catalyze the OER process on a variety of electrodes.The Fe(Ⅲ)-catalyzed overall water-splitting electrolyzer comprising bare Ni foam as the anode and Pt/Ni-Mo as the cathode demonstrates robust stability for 1600 h at 1000 mA cm^(-2)@~1.75 V.The results provide insights into the ioncatalyzed effects boosting OER performance.
基金financially supported by the Guangdong Basic and Applied Basic Research Foundation(No.2022A1515110212)the Special Fund Project for Science and Technology Innovation Strategy of Guangdong Province(Nos.STKJ202209077,STKJ202209083,and STKJ202209021)+1 种基金Scientific Research Foundation of Shantou University(No.NTF21022)City University of Hong Kong Strategic Research Grant(SRG)(No.7005505)。
文摘Bi VO_(4)is a promising semiconducting photoanode for photoelectrochemical(PEC)water splitting due to its suitable bandgap.However,the dissolution of V^(5+)and sluggish reaction kinetics at the surface in the oxygen evolution reaction(OER)limit its applications.Herein,we report a convenient strategy to change the microenvironment by adding Fe(Ⅲ)into the electrolyte.During the PEC process,Fe(Ⅲ)ions not only improve the current density,but also show excellent stability toward Bi VO_(4).Consequently,the current increases by more than 1.7 times compared to that without Fe(Ⅲ).Photoelectrochemical,morphological,and structural characterizations reveal that the FeOOH co-catalyst produced in situ on the Bi VO_(4)photoanode by cyclical formation of the intermediates at the electrode/electrolyte interface during OER accelerates the OER kinetics and prevents photo-corrosion by suppressing the dissolution of V^(5+).The results reveal a new strategy for the multifunctional modification of photoanodes for efficient solar conversion.
