Shuang Yang,ab   Cheng-Yan Xu,*ab   Li Yang,a   Sheng-Peng Huabc  and  Liang Zhen*ab  

Abstract

Hexagonal indium selenide (γ-In2Se3) nanoparticles were successfully synthesized by a hot-injection method using triethylene glycol as a solvent. The structure and morphology of the obtained nanoparticles were characterized by powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). Phase-pure γ-In2Se3 nanoparticles could be obtained at a relatively low temperature of 220 °C. Further increasing the reaction temperature leads to enhanced crystallinity of the γ-In2Se3 nanoparticles, which favors improving the photocatalytic activity. The γ-In2Se3 nanoparticles synthesized at 250 °C exhibit excellent and stable photocatalytic hydrogen generation under simulated sunlight irradiation, which might be attributed to the strong absorbance both in the UV and visible light regions as well as their nano-sized morphology.

Photocatalytic hydrogen evolution

The photocatalytic hydrogen evolution was performed with a CEL-SPH2N photocatalytic hydrogen generation system (Beijing Au-light, China). A 300W xenon lamp (CEL-HXF300, Beijing Au-light, China, wavelength 200-1100nm;I=20A） was used as simulated sunlight source. The incident light intensity was 364 mW cm²(CEL-NP2000 optical power meter).