WO3 has been identified as one of the promising visible light responsive materials for photoelectrochemical applications. However, pristine WO3 usually exhibits low photocatalytic properties due to its low absorption coefficient and inefficient charge separation. In this work we have successfully enhanced the incident photon-to-current efficiency (IPCE) of thin film WO3 photoanode by subjecting it to in situ post-reducing treatment. Such treatment resulted in 8 times increase in IPCE measured in visible light region (λ = 425 nm), coinciding with the increase in the charge separation efficiency up to 85%. In comparison to the pristine samples, the reduced WO3 photoanodes exhibited increase in charge carrier concentration, with corresponding increase in photocurrent density by approximately 100%. Further in situ post-reducing treatment of photoanodes resulted in decrease in the photocurrents, which can be attributed to a mismatch between depletion width and reduction depth.

Enhanced charge separation and visible light photon-to-current efficiency in high-performance WO3 thin-film photoanodes

253rd National Meeting (2017)

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