Assembling BiOBr nanoplates on MIL-125(Ti)–NH2 via group linkage towards effective dye-contaminated water purification

BiOBr-based photocatalysts have drawn a lot of interests for their favorable properties. However, the limitations in terms of active site accessibility and electron-hole separation hinder their practical applications. In this work, BiOBr was in situ synthesized in the presence of MIL-125(Ti)–NH2 under room temperature, constructing a series of BiOBr/MIL-125(Ti)–NH2 composites. The MIL-125(Ti)–NH2 which is rich in carboxyl and amino groups, facilitates the nucleation of BiOBr nanoplates to induce the formation of 3D flower-like structure, thus promoting the contact between photocatalysts and pollutants. What's more, heterojunction structures fabricated from BiOBr and MIL-125-NH2 can realize the rapid transfer of charge carriers. In comparison to bare components, the resultant composites presented boosted methyl orange (MO) removal efficiency, in which 91 % degradation rate of MO was achieved over the optimal sample BTN-4 and maintained at 84 % after four cycles. Finally, a reasonable photocatalytic mechanism was put forward to illustrate the superior effectiveness. [Display omitted] •A novel 3D hierarchical flower-like BiOBr/MIL-125(Ti)–NH2 heterostructure was fabricated under room temperature.•The z-scheme heterojunction can be formed in the composite to improve the photocatalytic degradation performance for MO.•Stronger adsorption ability and inhibited electron-hole pair combination enhanced photocatalytic performance.•Reasonable photocatalytic mechanism of MO was proposed.