High-efficient TiO2 NRs/BiOI NSs heterojunction photoanodes for photoelectrochemical water splitting

In this article, we report the preparation of a novel 1D/2D TiO2 NRs/BiOI NSs photoanode via a simple hydrothermal method followed by SILAR method. This facile synthesis route can simultaneously achieve uniform TiO2 NRs/BiOI NSs composite nanostructures and obtain varied thick of BiOI NSs by controlling the SILAR cycles. The TiO2 NRs/BiOI-3 (SILAR cycles of 15 cycles) heterojunction photoanode enhanced highest photocatalytic activity with a photocurrent density of 0·40 mA cm–2 at 1·23 V versus RHE compared to pristine TiO2 NRs photoanode at the same condition. It is demonstrated that the presence of BiOI NSs has played an important role in expanding the spectral response region and reduced photogenerated charges recombination rate. More importantly, the results provide new insights in the 1D/2D NRs/NSs composite structure served as photoanodes for PEC water splitting.