Tailored fabrication of interface-rich hierarchical Bi24O31Br10 with enhanced photocatalytic performance

Constructing Bi-rich photocatalysts has been regarded as a promising strategy for promoting the photocatalytic performance of bismuth oxyhalides, however, tailored fabrication of Bi-rich bismuth oxyhalides with hierarchical structure still remains unexplored. Hereof, Bi24O31Br10 hierarchical hexagonal nanoplates (HPs) are fabricated via facile co-precipitation with subsequent hydrothermal (solvothermal) treatment. The ethylene glycol coordination induced dissolving-recrystallization of one-dimensional Bi24O31Br10 nanobelts (NBs) gives rise to the construction of such unique hierarchical structure. Attributed to the compact intersecting and stacking of nanosheets in this hierarchical structure, Bi24O31Br10 HPs are rich in interfaces relative to Bi24O31Br10 hierarchical flowers (HFs) constructed by sparsely assembled nanosheets. The abundant interfaces endow hierarchical structure with enhanced charge storage ability for suppressing rapid electron-hole recombination, leading to facilitated separation of photogenerated charge carriers. Thanks to this advantage, Bi24O31Br10 HPs display standout catalytic properties in comparison with Bi24O31Br10 HFs with fewer interfaces and Bi24O31Br10 NBs without hierarchical structure, which only need 20 min and 30 min to reduce 94% of Cr(VI) and degradation of 90% OTC under visible light illumination, respectively. This work not only presents the first report about the fabrication of Bi24O31Br10 hierarchical hexagonal nanoplates, but also discloses the pivotal role of interfaces in boosting the photocatalytic performance of hierarchical photocatalysts.