Lead-free halide perovskites have emerged as promising alternatives to Pb-based materials for optoelectronic and photocatalytic applications. Among them, the A3B2X9 (A = Cs+, B = Sb3+, X = halide) is particularly attractive due to its structural versatility, chemical stability, and environmentally benign composition. This work aims to investigate the effect of halide mixing (Cl/Br) on the structural, optical, and potential photocatalytic properties of Cs3Sb2X9 compounds, with a focus on bandgap tunability and phase evolution. A series of mixed-halide Cs3Sb2X9 (X = Cl, Br) compounds were synthesized using a solvent-free ball-milling approach, enabling rapid and scalable preparation. Structural characterization reveals that Cs3Sb2Br9, Cs3Sb2Cl6Br3, and Cs3Sb2Cl3Br6 crystallize in a trigonal P-3m1 structure, whereas the chloride end member Cs3Sb2Cl9 adopts an orthorhombic Pnma phase. Optical analysis shows a systematic bandgap tuning from 2.85 eV (Cs3Sb2Cl9) to 2.51 eV (Cs3Sb2Br9), consistent with halide-dependent band gap tuning. Beyond structural and optical properties, Sb-based halide perovskites show potential in photocatalytic applications, including dye degradation, owing to their suitable band alignment and improved environmental compatibility compared to Pb-based systems. In this context, the present compositional series provides a platform to systematically investigate the role of halide mixing on photocatalytic activity. Ongoing work focuses on evaluating photocatalysis to establish composition–property–activity relationships. These results demonstrate that the change in the octahedral is effective approach for tuning the optoelectronic properties of Cs3Sb2X9 compounds. The use of leadfree compounds is important for sustainable photocatalytic applications.
Comissão Organizadora
Pedro Alves da Silva Autreto
Comissão Científica
Ferramenta completa de submissão, avaliação e publicação de anais para eventos científicos.
