Catalysis Today, Vol.314, 28-41, 2018
Preparation of perovskites PbBiO2I/PbO exhibiting visible-light photocatalytic activity
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 1.159x10(-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, O-2(-) and O-1(2), and a minor active species, h(+), can be produced for the CV degradation.