One-step hydrothermal synthesis of MIL-88A/BiOCl0.1Br0.9(M88/BCB) solid solution Z-scheme heterojunction photocatalysts

In this paper, M88/BCB Z-scheme heterojunction photocatalysts were synthesized by a one-step hydrothermal method. A series of characterization analyses showed that the introduction of iron-based MOF material M88 with mixed valence (Fe2+/Fe3+) increased not only the specific surface area of BCB, which was 2.2 times higher than that of BiOCl0.1Br0.9 solid solution, but also the existence of Fe2+/Fe3+ redox centers promoting the in situ photoFenton-like reaction, which could generate more O-center dot(2)- and (OH)-O-center dot. In addition, the introduction of M88 further enhances the visible light response capability of BCB and the separation efficiency of photogenerated carriers. Under visible light for 120 min, 10% M88/BCB can degrade 89.74% of TC, which is 2.1 times and 1.6 times higher than that of M88 and BCB, respectively. A possible photocatalytic degradation mechanism of Z-scheme heterojunctions was proposed based on the study of the band structure and the capture experiment of active species.