Enhancing the Visible Light Photoelectrochemical Water Splitting of TiO2 Photoanode via a p-n Heterojunction and the Plasmonic Effect

Developing visible light-responding photoelectrocatalysts with higher efficiency is highly demanded and broadly concerned in terms of photoelectrochemical (PEC) water splitting. Here, we report that by constructing a TiO2/CuInS(2 )p-n junction and further decorating it with plasmonic Cu nanoparticles, the synthesized TiO2/CuInS2/Cu photoanodes show significantly enhanced visible light absorption and higher photoelectrocatalysis efficiency, benefiting from the joint influence of the built-in electric field and surface plasmonic resonance (SPR). Under > 420 nm light irradiation, the photocurrent density is 2.36 mA/ cm2 at 1.23 V vs reversible hydrogen electrode (RHE), enhanced by about 10 times than that of pure TiO2. Furthermore, the hydrogen production rate was enhanced from an undetectable level to 4.552 mu mol/cm(2)/h. Our results exhibit that the strategy of a double-layer co-catalyst has promising applications in water splitting and other solar energy-conversion areas.

Automated summary

By constructing a TiO2/CuInS2/Cu photoanode with a p-n junction and plasmonic Cu nanoparticles, visible light absorption and photoelectrocatalysis efficiency have been significantly enhanced. The double-layer co-catalyst strategy shows promising applications in water splitting and solar energy-conversion areas.