Facet-Dependent Activity of Bismuth Bromide Nanosheets in Nonradical Fenton-like Catalysis

Two-dimensional metal oxide nanomaterials with abundant surface active sites are attractive for Fenton-like catalysis, but the performance improvement has been restricted by insufficient knowledge of the material structure–activity relationships. One remaining knowledge gap is how the crystal facet determines the catalytic activity in the nonradical Fenton-like oxidation of pollutants. Here, by using bismuth bromide (BiOBr) nanosheets as an example, we explored the different catalytic behaviors of its (010) over its (001) facets through both experimental and theoretical analyses. The (010) facet with abundant open channels allows much stronger binding and electronic interaction of PMS than the (001) facet to favor singlet oxygen (1O2) generation. Consequently, BiOBr-(010) exhibited one-order-of-magnitude higher bisphenol A degradation kinetics than BiOBr-(010), with a 4-fold enhancement in intrinsic activity. Its superior environmental robustness for selective pollutant degradation in a complicated water matrix, good stability during cyclic reactions, and feasibility for treating real water/wastewaters were also demonstrated. Overall, we demonstrate facet-dependent catalytic activity of BiOBr in nonradical Fenton-like catalysis and elucidate the catalytic mechanisms, which may guide the optimization of metal oxide catalysts to favor more efficient and selective decontamination applications.