LAUSR

Abstract Halide perovskites have shown great potential in photocatalytic applications. In order to enhance the charge transportation efficiency, the chemical stability, and the light absorption ability, we anchored a lead-free halide perovskite (Cs3Bi2I9) on UV100–TiO2 nanoparticles to build a visible-light active photocatalysts. The as-prepared material exhibited excellent stability and a remarkable yield for photocatalytic oxidation of methanol to formaldehyde under visible light irradiation. The photocatalyst was characterized using X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Transmission electron microscopy, X-ray photoelectron spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, Brunauer–Emmett–Teller surface area measurement, and photoelectrochemical properties. The analyses confirmed a remarkable improvement of visible-light absorption, a favorable decrease in the recombination of photoinduced charge carriers, and a suitable bandgap for visible-light photocatalytic applications. Recycle experiments showed that the composites still presented significant photocatalytic activity after three successive cycles. A possible underlying mechanism of the composite accounting for the enhanced photocatalytic activity under visible light irradiation was proposed. Our study aims to open new possibilities of using lead-free halide perovskites for photocatalytic applications.