Embedding CsPbBr3 perovskite quantum dots into mesoporous TiO2 beads as an S-scheme heterojunction for CO2 photoreduction

Heterojunction engineering, especially S-scheme heterojunction, has been recognized as a promising way to explore photocatalysts with boosted charge separation and CO2 photoreduction. Herein, we develop a CsPbBr3@mesoporous TiO2 beads (MTB) S-scheme heterojunction by embedding CsPbBr3 perovskite quantum dots (QDs) into the pores of MTB. The intimate interfacial interaction and staggered band structures promised the S-scheme charge transfer route, as confirmed by X-ray photoelectron spectra (XPS), electron spin resonance (ESR), etc. The 0.15CsPbBr3@MTB (15 wt% of CsPbBr3) hybrid exhibited a remarkable yield of 145.28 μmol g−1h−1 for CO2 photoreduction under simulated sunlight irradiation, which was 4.64 and 3.49-fold enhancement than the pristine MTB and CsPbBr3, respectively. This study provides useful guide towards the design of perovskite-based heterojunctions for photocatalytic applications.