Cr-doped barium stannate perovskite as an advanced photocatalyst for degrading carcinogenic rhodamine B

Abstract

Carcinogenic dyes such as Rhodamine B (RhB) pose severe environmental and public health concerns due to their toxic nature and resistance to conventional treatment processes. In this work, we have synthesized a series of chromium-doped barium stannate (BaSn<inf>1-x</inf>Cr<inf>x</inf>O<inf>3</inf>, x = 0.025–0.10) photocatalysts through a facile hydrothermal approach to effectively address this problem. Structural characterization revealed that increasing chromium doping above a critical level (2.5 %) results in the formation of SnO<inf>2</inf> and BaCrO<inf>4</inf> secondary phases, transforming the initial oxide into a BaSnO<inf>3</inf>/SnO<inf>2</inf>/BaCrO<inf>4</inf> ternary heterostructure. Photocatalytic studies under visible light demonstrated that the catalyst with 7.5 % Cr doping (7.5CBSO) achieved approximately 99 % degradation of RhB within 30 min, exhibiting an impressive pseudo-first order rate constant of 0.172 min−1. This superior activity arises from the synergistic interaction within the BaSnO<inf>3</inf>/SnO<inf>2</inf>/BaCrO<inf>4</inf> heterojunction, in which BaCrO<inf>4</inf> acts as an efficient visible-light sensitizer, and the favorable staggered band alignment significantly reduces electron-hole recombination. Our findings clearly indicate that controlled phase transformation offers an effective strategy for designing multi-component heterostructured photocatalysts with enhanced visible-light driven performance, highlighting potential applications in industrial wastewater treatment and environmental remediation. © 2025 Elsevier Ltd and Techna Group S.r.l. All rights are reserved, including those for text and data mining, AI training, and similar technologies.