One-Step Construction of Novel PbBiO2Br/ZnO Heterojunction Composites with Enhanced Photocatalytic Activity

PbBiO2Br/ZnO heterojunction composites are synthesized using a one-step method. The as-synthesized samples are characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), field-emission scanning electron microscopy (FE-SEM), energy-disperse X-ray spectroscopy (EDX), transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), Brunauer-Emmett-Teller (BET), ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), and photoluminescence (PL) spectroscopy. The photocatalytic activity of the PbBiO2Br/ZnO heterojunction composites is assessed by measuring the removal of methyl orange (MO) from wastewater under simulated sunlight irradiation. The results demonstrate that the PbBiO2Br/ZnO heterojunction composites are composed of ZnO nanorods and PbBiO2Br cubic nanosheets. The PbBiO2Br/ZnO heterojunction composites exhibit enhanced photocatalytic performances for the degradation of MO under irradiation by simulated sunlight. Among the composites, the 10% PbBiO2Br/ZnO composite exhibits optimal activity, and the removal percentage of the dye reaches 92.1% after 60 min of reaction. This is mainly attributed to the efficient separation of photo-generated e(-)-h(+) pairs and the formation of heterojunctions. According to the active species trapping experiments, photo-generated h(+) is confirmed to be the main active species, whereas center dot O2- and center dot OH play a secondary role in the reaction process. Additionally, the recycling experiments suggest that the PbBiO2Br/ZnO composites have good stability in the reaction process.