3D cross-linked lamellar bismuth silicate with lamellar porous and double heterostructure and its photocatalytic performance under visible light

Abstract

The improvement of photocatalytic performance is limited by the reduction of carrier redox capacity. Effective design of micromorphology and heterostructure is expected to overcome this obstacle. 3D cross-linked Bi2O2SiO3-BiOM-Si2Bi24O40 (BSO-BOM, M∈Cl, Br, I) with lamellar porous and double heterostructure are prepared in situ by an environmentally friendly hydrothermal deposition method. The process parameters are continuously optimized by exploring the modification effect of the pore-forming agent SiO2 and different halides in the composite preparation. The introduction of SiO2 changes the morphology of BSO, and a more effective heterogeneous interface interaction can be obtained in BSO-BOM. The construction of 3D cross-linked BSO-BOM with lamellar porous structure makes BSO-BOB better for nanocrystallization, which reduces material agglomeration, shortens the physical distance of carrier migration to the surface, and has a more suitable band gap position. Thereby accelerating the migration and diffusion of h+ so that it directly reacts with rhodamine B (Rh B) to form CO2 and H2O. After adjustment, these photocatalysts can reach 81.98% (BSO-BOI, 150 min), 98% (BSO-BOC, 90 min) and 100% (BSO-BOB, 60 min) of Rh B degradation, respectively. This work provides a feasible strategy for morphology control and free radical modification of heterogeneous photocatalysts.