N Doped Carbon Dot Modified WO3 Nanoflakes for Efficient Photoelectrochemical Water Oxidation.

It is a serious challenge to develop photoanodes with fast charge separation efficiency and surface reaction kinetics. Herein, the N doped carbon dot modified WO3 nanoflake (NCDs/WO3) is constructed by impregnation method. The resulting NCDs/WO3 exhibits an excellent photocurrent density of 1.42 mA cm−2 (1.0 V vs saturated calomel electrode, SCE) in 1 m H2SO4 solution under AM 1.5 G irradiation, which is 2.25 times higher than that of the pristine WO3. In addition, the onset potential of NCDs/WO3 photoanode represents a cathodic shift of 70 mV, indicating the charge separation and transfer process are both promoted. These results demonstrate N doped CD modified WO3 can further enhance the conductivity and electrochemical activity surface area, which contributes to the higher photoelectrochemical (PEC) performance. This work provides an efficient strategy for the development of doping carbon material with heteroatoms to increase the charge transfer and charge separation efficiency in PEC water oxidation. Nitrogen doped carbon dots modified WO3 nanoflakes are studied to strengthen the light absorption and to accelerate the charge separation and transfer efficiency of WO3 nanoflakes. Nitrogen doping improves the electrical conductivity and electrochemical activity surface area of carbon dots, which is beneficial for promoting the photoelectrochemical performance of WO3. [ABSTRACT FROM AUTHOR]