Solar water splitting has received increasing attentions in recent years as a very promising strategy to produce clean hydrogen fuels. This paper presents a novel design consisting of a sandwich structure of Fe2O3/Au/Fe2O3 as the photoanode for photoelectrochemical (PEC) water splitting. The tandem layers are constructed by spin-coating of pre-synthesized Fe2O3 nanoparticles and sputtering of the gold intermediate layer. PEC testing shows that the sandwich structure exhibits much higher photocurrent density as compared to the Fe2O3 double-layer anode. Further studies indicate that the Au intermediate layer can contribute in electron transfer as well as light harvesting due to its plasmonic excitation. The mechanism of the photocurrent enhancement is proposed and such sandwich structure may be applied to other semiconductors to improve PEC performance.

NRF (Natl Research Foundation, S’pore)

MOE (Min. of Education, S’pore)