Lead-Free Cs 2 TeX 6 (X = Cl, Br, and I) Perovskite Microcrystals with High Stability for Efficient Photocatalytic CO 2 Reduction.

In response to calling for a sustainable and carbon-neutral economy, the conversion of CO 2 to useful chemicals using the solar energy is a potential tactic to relieve the global energy dilemma and environmental issues, which has been a hot topic so far. Recently, the lead halide perovskites as novel photocatalysts have attracted researchers' interests. However, they generally encounter poor stability and lead toxicity, restricting their large-scale practical applications. Here, the lead-free Cs 2 TeX 6 (X = Cl, Cl 0.5 Br 0.5 , Br, Br 0.5 I 0.5 , and I) perovskite microcrystals with strong stability were prepared and used to realize the CO 2 photocatalytic reduction efficiently. The prepared Cs 2 TeBr 6 microcrystals delivered stronger photocatalytic ability than many previously reported photocatalysts, with the CO and CH 4 yields of 308.63 and 60.42 μmolg -1 , respectively, under 3 h of illumination. The presented strategy in our work provides new ideas of designing and preparing efficient and practical CO 2 reduction photocatalysts based on nonleaded and high-stability halide perovskites.