Ag-nanoparticle-decorated ZnO/ZnSe core-shell heterostructure and its enhanced photoelectrochemical performance

Zinc oxide (ZnO), a semiconductor material, has been widely explored due to its unique photoelectric properties. However, its application in photoelectric chemistry is limited by its fast recombination of excited electron-hole pairs and narrow wavelength range of light absorption. Here, we report a novel Ag-nanoparticle-decorated ZnO/ZnSe core-shell heterostructure, which greatly enhances the photoelectrochemical properties compared with pure ZnO. The nanocomposites, consisting of ZnO nanorods as the core and Ag-nanoparticle-decorated zinc selenide (ZnSe) as the shell, were synthesized via an improved low-temperature hydrothermal method combined with in-situ selenization-chemical vapor deposition and nanoparticle self-assembly techniques. The material presents a much higher photocurrent density than pure ZnO material with sub-millisecond response time and excellent stability. Our synthetic strategy may open up a new way to enhance photoelectrochemical performance of core-shell heterojunctions, which could find plausible applications in photodetectors and optoelectronic devices.