By using the surface photovoltage (SPV) technique based on a lock-in amplifier, surface states located 3.1 eV below the conduction band of TiO_(2) have been detected in TiO_(2) nanotube arrays prepared by anodization ...By using the surface photovoltage (SPV) technique based on a lock-in amplifier, surface states located 3.1 eV below the conduction band of TiO_(2) have been detected in TiO_(2) nanotube arrays prepared by anodization of titanium foil in fluoride-based ethylene glycol solution. The photo-induced charge transportation behavior of TiO_(2) nanotube arrays was also studied by quali- tatively analyzing their SPV phase spectra measured under different external bias. When a negative bias was applied, carriers excited from surface states have the same transportation properties as those excited from the valence band; in contrast, when a positive bias was applied, these two kinds of photo-excited carriers exhibit different transportation behavior..展开更多
Ti-Fe2O3 photoanode has received widespread attention in photoelectrochemical(PEC)water spilling because of its optimized oxidative and reductive capability of composites catalyst.However,its low efficiency could limi...Ti-Fe2O3 photoanode has received widespread attention in photoelectrochemical(PEC)water spilling because of its optimized oxidative and reductive capability of composites catalyst.However,its low efficiency could limit its development.Herein,in order to improve the efficiency of PEC water spilling,the all-solid-state direct Z-scheme Ti-ZnFe2O4/Ti-Fe2O3(TZFO/Ti-Fe2O3)nanorod arrays composited with the ideal energy band structure are synthesized by modulating the Fermi level of TZFO for PEC water splitting.The photophysical methods in this work,including the Kelvin probe measurement and transient photovoltage spectroscopy(TPV)measurement,are applied to explore the migration behavior of electric charges at the enhanced interface electric field.Finally,the Z-scheme charge transfer mechanism of TZFO/Ti-Fe2O3 photoanode is proved successfully.Benefiting from the desirable charge transfer at interface electric field,the TZFO/Ti-Fe2O3 exhibits the outstanding photocatalytic oxygen evolution reaction(OER)performance,and the photocurrent of 60TZFO/Ti-Fe2O3 photoanode reaches 2.16 mA/cm^2 at 1.23 V vs.reversible hydrogen electrode(RHE),which is three times higher than that of pure Ti-Fe2O3 photoanode.This work provides a facile approach of modulating interface electric field to optimize the Z-scheme charge-transfer process.展开更多
基金supported by the National Basic Research Program of China (973 Program,2007CB613303)the National Natural Science Foundation of China (20873053)
文摘By using the surface photovoltage (SPV) technique based on a lock-in amplifier, surface states located 3.1 eV below the conduction band of TiO_(2) have been detected in TiO_(2) nanotube arrays prepared by anodization of titanium foil in fluoride-based ethylene glycol solution. The photo-induced charge transportation behavior of TiO_(2) nanotube arrays was also studied by quali- tatively analyzing their SPV phase spectra measured under different external bias. When a negative bias was applied, carriers excited from surface states have the same transportation properties as those excited from the valence band; in contrast, when a positive bias was applied, these two kinds of photo-excited carriers exhibit different transportation behavior..
基金Supported by the National Natural Science Foundation of China(Nos.51572106,21773086,21872063).
文摘Ti-Fe2O3 photoanode has received widespread attention in photoelectrochemical(PEC)water spilling because of its optimized oxidative and reductive capability of composites catalyst.However,its low efficiency could limit its development.Herein,in order to improve the efficiency of PEC water spilling,the all-solid-state direct Z-scheme Ti-ZnFe2O4/Ti-Fe2O3(TZFO/Ti-Fe2O3)nanorod arrays composited with the ideal energy band structure are synthesized by modulating the Fermi level of TZFO for PEC water splitting.The photophysical methods in this work,including the Kelvin probe measurement and transient photovoltage spectroscopy(TPV)measurement,are applied to explore the migration behavior of electric charges at the enhanced interface electric field.Finally,the Z-scheme charge transfer mechanism of TZFO/Ti-Fe2O3 photoanode is proved successfully.Benefiting from the desirable charge transfer at interface electric field,the TZFO/Ti-Fe2O3 exhibits the outstanding photocatalytic oxygen evolution reaction(OER)performance,and the photocurrent of 60TZFO/Ti-Fe2O3 photoanode reaches 2.16 mA/cm^2 at 1.23 V vs.reversible hydrogen electrode(RHE),which is three times higher than that of pure Ti-Fe2O3 photoanode.This work provides a facile approach of modulating interface electric field to optimize the Z-scheme charge-transfer process.
