Preparation, characterization and enhancement of the visible-light photocatalytic activity of In2O3/Na-bentonite composite

Abstract

To overcome the drawback of low photocatalytic efficiency brought by electron–hole recombination and low adsorbability of In2O3, we successfully synthesized In2O3/Na-bentonite composites using a sol-gel method by intercalating In2O3 nanoparticles into Na-bentonite matrices. The as-prepared samples were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), nitrogen adsorption/desorption measurements and UV–vis diffuse reflectance spectra (UV–vis DRS). The In2O3/Na-bentonite composite possesses a wide photoabsorption until 700nm, which occupies nearly the whole range of the visible light. Compared with bare In2O3, the In2O3/Na-bentonite composite exhibits significantly enhanced photocatalytic activity for phenol degradation under visible light irradiation. On the basis of the the experimental results, the mechanism of enhanced photocatalytic activity was can be attributed to the effective separation of electron–holes pairs and high adsorbability. The present study provides a new strategy to design composite materials with enhanced photocatalytic performance of In2O3.