Exploring the Photocatalytic Potential of Lead-Free Cs2AgxNa1–xBiCl6 Double Perovskites: Influence of Ag/Na Composition and Nanocrystalline Heterojunction Formation Induced by In Situ Water Interaction
Year: 2025
Type: article
Abstract: High Resolution Image Download MS PowerPoint Slide Lead-free halide double perovskites (A 2 B I B III X 6 ) have recently emerged as promising candidates in photocatalysis, demonstrating potential for applications such as CO 2 photoreduction, H 2 evolution, and organic pollutant degradation. However, the influence of monovalent metal cation composition, particularly Ag + and Na +, on their photoactivity performance remains poorly understood, and their behavior in aqueous media has been insufficiently explored. In this study, we synthesized double perovskites, Cs 2 Ag x Na 1– x BiCl 6, with varying Ag/Na ratios and systematically evaluated their photocatalytic activity in both aqueous and ethanolic environments. Density Functional Theory (DFT) simulations were conducted to analyze their electronic structures and charge carrier stability. By correlating experimental characterization, theoretical calculations, and photocatalytic performance, we uncovered critical insights into the role of Ag + and Na + in tuning the photoactivity of these lead-free perovskites. Our results indicate that increasing the Ag + content reduces the intrinsic photocatalytic activity of Bi-based double perovskites in ethanolic media, a trend attributed to changes in charge carrier stability, according to DFT. In contrast, the opposite effect was observed in aqueous media, where higher Ag + concentrations enhanced photocatalytic performance. This behavior was linked to the complete structural conversion of the perovskite in water, leading to the in situ formation of a BiOCl/AgCl heterojunction with superior photocatalytic properties. These findings offer valuable insights into the interplay between composition, water stability, and photocatalytic efficiency, providing a foundation for the rational design of advanced photocatalysts derived from lead-free metal halide double perovskites.
Language: English
Field: Energy
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $4,500
Funders: Fundação de Amparo à Pesquisa do Estado de São Paulo, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, Ministério da Ciência, Tecnologia e Inovação, Conselho Nacional de Desenvolvimento Científico e Tecnológico, Centro Nacional de Processamento de Alto Desempenho em São Paulo, Division of Graduate Education
Awards: G1454137543, G1860102177, G1934264159, G2073493084, G2127543742, G321761023, G3690646728, G5388512481, G5553000992, G5937996916, G5976378774, CO2 as a raw material for hybrid multi-functional materials: improving the sustainability of industrial processes, G6438247056, G6981248826, G6992396269, Antimicrobial nanocomposites of hydroxyurethanes with inorganic acids, G8521211124
OpenAlex ID: W4414154979