Abstract:

Metal halide perovskites have attracted increasing attention in recent years due to their outstanding physico-chemical properties and excellent performance in diverse photocatalytic reactions. However, most studies focus on lead-based perovskites, whose toxicity has driven the search for safer alternatives. In this context, the present work investigates Bi-based halide perovskites as a more sustainable option. Despite their potential, halide perovskites still suffer from intrinsic limitations, most notably their instability under moisture. One of the objectives of this study is therefore to enhance their stability for selective C–H bond activation, employing silica and zeolite Y as a supporting matrix. In addition, the field of Bi-based mixed halide perovskites remains largely unexplored. Here, the effect of incorporating Ru, Ni, and Ce into Cs3Bi2Br9 is examined through XRD, UV–Vis, photoluminescence spectroscopy, and complementary techniques. A key objective of this work is to evaluate these heteroatom-incorporated perovskites in polystyrene depolymerization reaction, for which halide perovskites have not yet been reported in the literature. This represents the main innovation of the study. A proof-of-concept is presented for polystyrene depolymerization over modified perovskites, and the formation of acetophenone, styrene, benzoic acid and benzaldehyde have been detected. These preliminary results demonstrate that halide perovskites can be successfully applied to this type of reaction, potentially opening new opportunities in plastic recycling and in the broader application of halide perovskites.