Lead-Free Cs₂TeX₆ (X = Cl, Br, and I) Perovskite Microcrystals with High Stability for Efficient Photocatalytic CO₂ Reduction

In response to calling for a sustainable and carbon-neutral economy, the conversion of CO2 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 Cs2TeX6 (X = Cl, Cl0.5Br0.5, Br, Br0.5I0.5, and I) perovskite microcrystals with strong stability were prepared and used to realize the CO2 photocatalytic reduction efficiently. The prepared Cs2TeBr6 microcrystals delivered stronger photocatalytic ability than many previously reported photocatalysts, with the CO and CH4 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 CO2 reduction photocatalysts based on nonleaded and high-stability halide perovskites

Boosting CO₂ Conversion by Synergy of Lead-Free Perovskite Cs₂SnCl₆ and Plasma with H₂O

Although dielectric barrier discharge (DBD) plasma is a promising technique for CO2 conversion, realizing CO2-to-alcohol is still challenging via the use of H2O. Herein, for the first time, efficient CO2 conversion was achieved via the synergism between the Cs2SnCl6 photocatalyst and DBD plasma assisted by H2O. The CO2 conversion ratio of plasma photocatalysis was 6.5% higher than that of only the plasma and photocatalysis, implying that the synergism of plasma catalysis and photocatalysis was achieved. Furthermore, the DBD plasma assisted by the Cs2SnCl6 photocatalyst could convert CO2 and H2O to CO and a small amount of methanol and ethanol. The CO2 conversion ratio was enhanced by 50.6% in the presence of H2O, which was attributed to the improvement of charge transfer due to the increased electrical conductivity of the photocatalyst surface during plasma discharge. This work provides a new idea for developing an efficient system for CO2 utilization