Facile fabrication of BiOCl nanoplates with high exposure {001} facets for efficient photocatalytic degradation of nitro explosives

Nitro explosives are harmful to the ecological environment and human health and they are difficult to eliminate. Herein, a simple and environmentally friendly citric acid modulated hydrothermal method was used to prepare regular square-like BiOCl nanoplates with high exposure {001} facets. The results of characterizations showed that reduced-size square-like BiOCl nanoplates were with high exposure {001} facets. Nitro explosives, including p-nitrophenol (PNP), 2,4-dinitrophenol (2,4-DNP), 2,4,6-trinitrophenol (2,4,6-TNP), and 2,4,6-trinitrotoluene (TNT), were selected to inquire into the catalytic properties of prepared samples under simulated irradiation. The catalytic performance of BC-10 was the best. In particular, BC-10 could thoroughly degrade four nitro explosives solutions, namely, PNP, 2,4-DNP, 2,4,6-TNP, and TNT (20 mg L-1) under simulated irradiation in 50, 90, 90, and 90 min, respectively; photocatalytic mechanism was exhaustively discussed. Photoelectrochemical, in additon to electron paramagnetic resonance characterizations, suggested that the intrinsic factor for the superior photocatalytic performance was the enhancement of the transfer and separation efficiency of photogenerated charge carriers derived from the BiOCl {001} active facets. Moreover, the primary active substance in the system was superoxide radicals. This study may provide new insights on the preparation of efficient catalysts for degrading nitro explosives.