Hematite(α-Fe_(2)O_(3))is a promising photoanode for photoelectrochemical(PEC)water splitting.However,the severe charge recombination and sluggish water oxidation kinetics extremely limit its use in photohydrogen con...Hematite(α-Fe_(2)O_(3))is a promising photoanode for photoelectrochemical(PEC)water splitting.However,the severe charge recombination and sluggish water oxidation kinetics extremely limit its use in photohydrogen conversion.Herein,a co-activation strategy is proposed,namely through phosphorus(P)doping and the loading of CoAl-layered double hydroxides(CoAl-LDHs)cocatalysts.Unexpectedly,the integrated system,CoAl-LDHs/P-Fe_(2)O_(3) photoanode,exhibits an outstanding photocurrent density of 1.56 mA/cm^(2) at 1.23 V(vs.reversible hydrogen electrode,RHE),under AM 1.5 G,which is 2.6 times of pureα-Fe_(2)O_(3).Systematic studies reveal that the remarkable PEC performance is attributed to accelerated surface OER kinetics and enhanced carrier separation efficiency.This work provides a feasible strategy to enhance the PEC performance of hematite photoanodes.展开更多
The coupling of photoanode(Pho)and oxygen evolution catalyst(OEC)is an ideal approach to enhance the photoelectrochemical(PEC)activity.Nevertheless,the anticipated photocurrent density has not been reached due to slow...The coupling of photoanode(Pho)and oxygen evolution catalyst(OEC)is an ideal approach to enhance the photoelectrochemical(PEC)activity.Nevertheless,the anticipated photocurrent density has not been reached due to slow charge transfer dynamics and severe charge recombination at the interface.Herein,a novel“killing two birds with one stone”approach was discovered by employing CoPi as an interface mediator,which shifts its charge transfer behavior from conventional hole storage or passivation to hole transporter.The optimized BiVO_(4)/CoPi/FeOOH photoanode achieves a noteworthy photocurrent density of 5.4 mA/cm^(2) and exhibits long term stability(13 h).The dynamic analysis and electrochemical characterization reveal that CoPi can rapidly and directly transfer more photogenerated holes to the surface of OEC in comparison to traditional slow holes transfer behavior,resulting in highly efficient interface charge separation.Interestingly,the strong interfacial interactions can also be extended to OEC/electrolyte interface,specifically by promoting the surface reaction dynamics.Moreover,this innovative approach of altering behavior of CoPi can also be utilized to design other photoanodes,like BiVO_(4)/CoPi/NiOOH,aimed at efficient PEC water splitting.This finding affords a smart strategy to develop highly efficient and stable photoelectrodes for water splitting.展开更多
基金supported by the National Natural Science Foundation of China(No.21575115)the Program for Chang Jiang Scholars and Innovative Research Team,Ministry of Education,China(No.IRT-16R61)。
文摘Hematite(α-Fe_(2)O_(3))is a promising photoanode for photoelectrochemical(PEC)water splitting.However,the severe charge recombination and sluggish water oxidation kinetics extremely limit its use in photohydrogen conversion.Herein,a co-activation strategy is proposed,namely through phosphorus(P)doping and the loading of CoAl-layered double hydroxides(CoAl-LDHs)cocatalysts.Unexpectedly,the integrated system,CoAl-LDHs/P-Fe_(2)O_(3) photoanode,exhibits an outstanding photocurrent density of 1.56 mA/cm^(2) at 1.23 V(vs.reversible hydrogen electrode,RHE),under AM 1.5 G,which is 2.6 times of pureα-Fe_(2)O_(3).Systematic studies reveal that the remarkable PEC performance is attributed to accelerated surface OER kinetics and enhanced carrier separation efficiency.This work provides a feasible strategy to enhance the PEC performance of hematite photoanodes.
基金the National Natural Science Foundation of China(Nos.22202126,52273186,51873100,and 62105194)San Qin Scholars Innovation Teams in Shaanxi Province,China,International Joint Research Center of Shaanxi Province for Photoelectric Materials Science,and International Science and Technology Cooperation Project of Shaanxi Province,China(No.2021KW-20).
文摘The coupling of photoanode(Pho)and oxygen evolution catalyst(OEC)is an ideal approach to enhance the photoelectrochemical(PEC)activity.Nevertheless,the anticipated photocurrent density has not been reached due to slow charge transfer dynamics and severe charge recombination at the interface.Herein,a novel“killing two birds with one stone”approach was discovered by employing CoPi as an interface mediator,which shifts its charge transfer behavior from conventional hole storage or passivation to hole transporter.The optimized BiVO_(4)/CoPi/FeOOH photoanode achieves a noteworthy photocurrent density of 5.4 mA/cm^(2) and exhibits long term stability(13 h).The dynamic analysis and electrochemical characterization reveal that CoPi can rapidly and directly transfer more photogenerated holes to the surface of OEC in comparison to traditional slow holes transfer behavior,resulting in highly efficient interface charge separation.Interestingly,the strong interfacial interactions can also be extended to OEC/electrolyte interface,specifically by promoting the surface reaction dynamics.Moreover,this innovative approach of altering behavior of CoPi can also be utilized to design other photoanodes,like BiVO_(4)/CoPi/NiOOH,aimed at efficient PEC water splitting.This finding affords a smart strategy to develop highly efficient and stable photoelectrodes for water splitting.
