NaBr-Assisted Aqueous Synthesis of Perovskite-Embedded PbBr(OH) Hierarchical Nanostructures for Dye Photodegradation

Halide perovskite nanomaterials have demonstrated promising potential in various fields, including photocatalysis for environmental remediation. However, perovskites' poor stability toward water makes it difficult to use them for the photocatalytic degradation of organic pollutants in wastewater. Herein, we develop a facile and scalable NaBr-assisted room-temperature aqueous phase procedure for the synthesis of all-inorganic CsPbBr3-embedded PbBr(OH) with controlled hierarchical structures, excellent ambient stability, and strong activity for photocatalytic degradation of dyes (e.g., methyl orange and methylene blue) in simulated organic wastewater. It is exceptional that the added NaBr can complex PbBr2 to form a transparent aqueous solution, enabling the subsequent reaction with the aqueous Cs2CO3 precursor to produce CsPbBr3-embedded PbBr(OH) microflowers and microspheres. The photocatalysis shows that the CsPbBr3-embedded PbBr(OH) photocatalysts exhibit excellent photocatalytic activity for dye degradation under visible-light irradiation, which is significantly stronger than that of commercial TiO2 and some other perovskite-based materials produced using a previously reported method. The excellent stability of the CsPbBr3-embedded PbBr(OH) as a photocatalyst is verified by nine consecutive photocatalytic cycles without a noticeable drop in photodegradation efficiency. This work will shed light on the green synthesis of ultra-stable perovskite-based nanomaterials for photocatalytic degradation of organic pollutants as well as other promising water treatment technology prospects.