Abstract
In this work, we explored a facile, scalable and effective method for substantially enhancing photocurrent and incident-photon-to-current efficiency of WO3 thin-film photoanodes by a mild reduction treatment under low oxygen pressure. Experimental data from photoelectrochemical and electrochemical impedance spectroscopies have shown that such treatment can increase the charge carrier density on WO3 photoanode surfaces resulting in improvements in hole collection efficiency and reduction in charge recombination. Despite a much thinner layer of WO3 (about 500 nm) compared to those in other published studies, the electrodes exhibited an ultra-high photocurrent density of 1.81 mA cm−2 at 1.23 V vs. RHE. This current density is one of the highest ones among WO3-based photoanodes described in literature. The proposed surface modulation approach offers an effective and scalable method to prepare high-performance thin film photoanodes for photoelectrochemical water splitting.
Highlights
IntroductionPaper it is still a challenge to develop highly efficient visible light absorbing photoanodes with very transparent oxygen evolution catalysts that can offer thermodynamic stability in acidic electrolytes.[18]
Water splitting in photoelectrochemical (PEC) cells is potentially the most promising method for converting solar energy into chemical energy
Experimental data from photoelectrochemical and electrochemical impedance spectroscopies have shown that such treatment can increase the charge carrier density on WO3 photoanode surfaces resulting in improvements in hole collection efficiency and reduction in charge recombination
Summary
Paper it is still a challenge to develop highly efficient visible light absorbing photoanodes with very transparent oxygen evolution catalysts that can offer thermodynamic stability in acidic electrolytes.[18]. Introduction of oxygen vacancies to the surface of semiconductors can be one promising strategy to improve WO3 photocatalytic efficiency while keeping relatively thin thickness.[28] Oxygen vacancies typically act as donor defects for n-type oxides, where they exert a signi cant in uence on space charge region (SCR) and charge recombination.[11,12,13,29] In addition, dual oxygen and tungsten vacancies have proven to signi cantly enhance the hole transfer efficiency at semiconductor electrolyte interface (SEI).[4] modulating the functions of vacancies at the surface of semiconductors using a nely controlled method can be a potentially promising way forward to design high performance thin lm PEC electrodes. We introduce a simple surface reduction method that can signi cantly enhance the performance of bare WO3 thin lm photoanodes, which are only 500 nm thick. The crosssectional SEM image of WO3 thin lm sample prepared by 40k laser pulses (Fig. 1b), which included ITO bottom electrode,
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call