Preparation of perovskites PbBiO2I/PbO exhibiting visible-light photocatalytic activity

Abstract

The first synthetic study on PbBiO2I/PbO nanocomposite preparation using a controlled hydrothermal method is reported. The morphologies and composition of the samples are controlled by adjusting some parameters, including reaction pH, Pb/Bi molar ratio, and temperature. All the samples are characterized by XRD, TEM, XPS, SEM-EDS, PL, BET, EPR, and UV–vis-DRS. The photodegradation activities are evaluated against the de-colorization of crystal violet (CV) and 2-hydroxybenzoic acid (2-HBA) in aqueous solution under visible light illumination. In particular, the catalytic performance illustrates the best reaction rate constant 1.159 × 10−1 h−1 once PbBiO2I/PbO is used as the photocatalyst for the degradation of CV; which is 3 and 20 times higher than the reaction rate constants of PbBiO2I and PbO being the photocatalysts, respectively. This study reveals that PbBiO2I/PbO can be used for repressing the recombination of photo-generated electron-hole pairs and contribute to the enhanced photocatalytic activity of semiconductors in the visible-light-driven catalysis. The possible photocatalytic degradation mechanism is studied by using different active species through EPR and adding suitable scavengers. When being irradiated, two major active species, O2− and 1O2, and a minor active species, h+, can be produced for the CV degradation.