Controlled hydrothermal synthesis of PbBiO2Br/BiOBr heterojunction with enhanced visible-driven-light photocatalytic activities

• This is the first report that PbBiO2Br/BiOBr is synthesized by hydrothermal method.
• PbBiO2Br/BiOBr exhibit enhanced photocatalytic activities on the CV degradation.
• The catalytic performance illustrates the best reaction rate constant 6.01 × 10−2 h−1.
• The results demonstrate that the reactive O2
• − plays the major and OH the minor roles.

This is the first report that PbBiO2Br/BiOBr is synthesized by a template-free hydrothermal method. The composition and morphologies of the samples could be controlled by adjusting some growth parameters, including reaction pH, Pb/Bi molar ratio, and temperature. All the samples are characterized by XRD, TEM, XPS, SEM-EDS, FT-IR, BET, EPR, and UV-vis-DRS. The PbBiO2Br/BiOBr photocatalysts exhibit enhanced photocatalytic activities on the degradation of crystal violet (CV) under visible-light irradiation. In particular, the catalytic performance illustrates the best reaction rate constant 1.257 × 10−1 h−1 once PbBiO2Br/BiOBr is used as the photocatalyst; which is 3 and 2 times higher than the reaction rate constant of PbBiO2Br and BiOBr being the photocatalysts, respectively. This study reveals that PbBiO2Br/BiOBr can be used to suppress the recombination of photoinduced electron-hole pairs and contribute to the enhanced photocatalytic efficiency of semiconductors in the visible-light-driven catalysis. The possible photodegradation mechanism is studied by examining different active species through EPR and adding appropriate scavengers. The results demonstrate that the reactive O2− plays the major and OH the minor roles in the CV degradation.

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