LAUSR

Promising mesoporous Bi24O31Br10/SrTiO3 (BOB/STO) nanocomposites were successfully designed and fabricated via a three-step approach. The morphology, structure, optical performance, surface area and pore-size distribution of the products were characterized by x-ray powder diffraction, x-ray photoelectron spectroscopy, field-emission scanning electron microscopy, transmission electron microscopy, energy-dispersive x-ray spectroscopy, diffuse reflectance spectroscopy and Brunner–Emmett–Teller analysis. The results indicate that BOB/STO nanocomposites are composed of perovskite STO nanoparticles and monoclinic BOB nanosheets. Compared with pure STO nanoparticles or BOB nanosheets, the mesoporous BOB/STO nanocomposites show a much better photocatalytic activity for the removal of methyl orange solution under simulated sunlight irradiation. In particular, the 10% BOB/STO composite is found to be the optimal composite, over which the dye decomposition reaches 95.3% for 100 min. The photocatalytic decomposition rate of the 10% BOB/STO nanocomposite is found to be 3.4 and 4.09 times higher than that of bare BOB and STO, respectively. The enhanced photocatalytic performance of the BOB/STO nanocomposites is attributed to the efficient charge separation and reduced recombination probability of photogenerated electron–hole (e−–h+) pairs. Furthermore, the BOB/STO nanocomposites show the considerable stability and recycling capacity in the reaction process. In addition, the photocatalytic mechanism of the BOB/STO nanocomposites is explained by a plausible Z-scheme heterojunction.