Solar Energy Materials and Solar Cells, Vol.185, 415-424, 2018
Turnip-inspired BiVO4/CuSCN nanostructure with close to 100% suppression of surface recombination for solar water splitting
Inspired by the morphologies and function of the root and the stalk of a turnip, which has evolved with the unique pattern of growth for enhancing transport phenomenon, a novel architecture of BiVO4/CuSCN architecture is fabricated on fluorine-doped tin oxide coated glass by initially fabricating bulky BiVO4 film (the root) and subsequently depositing p-type CuSCN nanorods (the stalk). With the creation of BiVO4/CuSCN nanorod heterojunction photoanodes, the photocurrent density increases to 1.78 mA cm(-2) compared to 1.22 mA cm(-2) of bare BiVO4 at 1.23 V vs. reversible hydrogen electrode. More importantly, the onset potential for oxygen evolution reaction exhibits a dramatic cathodic shift (similar to 230 mV). The heterojunction also possesses internal quantum efficiency of approximately 50% in the range from 350 to 450 nm with relatively high solar energy conversion efficiency (0.5%) and much higher oxidation efficiency (similar to 90%). The unique electrode architecture design favoring the simple water splitting process over conventionally fabricated electrode by providing more active sites and facilitates transportation and consumption of photoinduced holes could open up a new route for the high-efficiency photoanodes.