Lead-Free Cs<sub>2</sub>AgBiBr<sub>6</sub>/TiO<sub>2</sub> S-Scheme Heterojunction for Efficient Photocatalytic Antibiotic Rifampicin Degradation.

Jiang, Yin; Wang, Zhaoyang; Yang, Wen; Yang, Peizhi; Feng, Xiaobo; Qin, Peng; Huang, Fuqiang · Nano Lett · 2024

basic_science · Level V

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Abstract

Exploring efficient and stable halide perovskite-based photocatalysts is a great challenge due to the balance between the photocatalytic performance, toxicity, and intrinsic chemical instability of the materials. Here, the environmentally friendly lead-free perovskite Cs<sub>2</sub>AgBiBr<sub>6</sub> confined in the mesoporous TiO<sub>2</sub> crystal matrix has been designed to enhance the charge carrier extraction and utilization for efficient photocatalytic rifampicin degradation. The as-prepared Cs<sub>2</sub>AgBiBr<sub>6</sub>/TiO<sub>2</sub> catalyst was stable in air for over 500 days. An S-scheme heterojunction was formed between the (004) plane of Cs<sub>2</sub>AgBiBr<sub>6</sub> and the (101) plane of TiO<sub>2</sub> through the Bi-O-Br bonds. The built-in electric field at the interface efficiently promoted the photoinduced charge separation and carrier extraction. The Cs<sub>2</sub>AgBiBr<sub>6</sub>/TiO<sub>2</sub>-200 showed a 92.83% degradation efficiency of rifampicin within 80 min under simulated sunlight illumination (AM 1.5G 100 mW cm<sup>-2</sup>). This work offers an effective way for the construction of halide perovskite-based photocatalysts with high photocatalytic performance, good stability, and low toxicity simultaneously.