Strong metal-carrier interactions via modulation of Pt oxidation states on defective BiOBr with greatly improved photocatalytic activity

Abstract

Herein, we fabricated Strong metal-carrier interactions in Pt-BiOBr via an in situ photodeposition method. It was found that the surface defects on BiOBr provided an electron-rich environment around the adjacent Bi species. With the introduction of Pt, Pt tended to substitute Bi into this electron-rich environment as an electron trap, causing electron transfer from the defective BiOBr to Pt. Therefore, an electron metal-support interaction (EMSI) was formed between Pt and the defective BiOBr, which further diminished the combination rate of photogenerated carriers. Furthermore, chemical state of Pt species was regulated by modulating the photodeposition atmosphere. When Pt0 coexisted with Ptδ+, Pt/BiOBr-OVs exhibited the highest photocatalytic activity. The EMSI formed by Ptδ+ and defective BiOBr as the primary factor, assisted by the LSPR effect of Pt0, the two synergistically achieved the most efficient electron transfer and the photocatalytic activity. Notably, the phenol degradation rate reached 82.40% and the COD removal rate reached 82.13% when illuminated for just 10 min. This work not only achieved the stabilization of Pt species through the strong chemical bond between Pt and BiOBr, but also gave the Pt species the best electronic structure.