Nanostructured Bi2O3@TiO2 photocatalyst for enhanced hydrogen production

Here we report on Bi2O3 clusters immobilized on anatase TiO2 nanostructures for an enhanced rate of photocatalytic H2 evolution. Structural, morphological, and optical properties of the Bi2O3@TiO2 nanocomposite (BT) were characterized by a series of techniques including X-ray diffraction, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy, diffuse reflectance spectroscopy and electrochemical impedance spectroscopy. The catalytic H2 evolution experiments were carried out under different light sources: natural solar light, LED UV (365 ± 5 nm) and LED visible (420 ± 5 nm) light source. Under the solar light a pristine anatase TiO2 nanostructured (TNS) catalyst generated 4.20 mmol h−1 g−1, whereas in the presence of Bi2O3@TNS showed much higher H2 production 26.02 mmol h−1 g−1. The photocatalytic activity of the BT and its reproducible performance for five recycles is ascribed to an efficient separation of photogenerated charge carriers. A plausible reaction mechanism for the H2 generation is proposed.