Partial Ion Exchange Derived 2D Cu–Zn–In–S Nanosheets as Sensitizers of 1D TiO2 Nanorods for Boosting Solar Water Splitting

A facile route for the fabrication of a novel ZnS shell/Cu–Zn–In–S nanosheets/TiO 2 nanorods heterojunction was reported in this work. Especially, the quaternary Cu–Zn–In–S nanosheets were synthesized creatively from the ternary ZnIn 2 S 4 nanosheets by partial exchange reaction, leading to substantial enhancement on the light absorbance. Such heterojunction could increase the surface area and accelerate the charge transfer resulting from its hierarchical 2D/1D structure and favorable energy bands. Moreover, the ZnS coating acted as a passivation layer as well as a potential barrier, significantly suppressing the interface recombination. The above synergistic effects resulted in the largely increased photocurrent density from 0.34 mA cm –2 for the pristine TiO 2 to 0.81 mA cm –2 for the heterojunction at 0.8 V vs RHE.