Crystal OH boosting piezocatalytic H2O2 synthesis by Bi3O(PO4)2OH from pure water for atrazine degradation

Abstract

Water oxidation reaction (WOR) is the key to achieving highly efficient H₂O₂ production but remains challenging, due to its poor selectivity, low activity, and unfavorable thermodynamics. Herein, a novel Bi₃O(PO₄)₂OH (BOHP) microcrystal was successfully synthesized for the first time using deep eutectic solvents and employed as a piezocatalyst for H₂O₂ production. Interestingly, under ultrasonication (80 W, 40 kHz), the BOHP can split pure H₂O into H₂O₂ with an exceptionally high generation rate of 639.11 μmol·g⁻¹·h⁻¹ without additional sacrificial agents. Mechanism studies demonstrate that the hydroxyl (–OH) groups in BOHP facilitate hydrophilicity, promoting water molecule activation and transformation while enhancing the piezoelectric response, thereby accelerating charge carrier separation. Additionally, the BOHP also exhibits efficient piezocatalytic degradation of atrazine (ATZ) by decomposing H₂O₂ in situ into active ·OH radicals, achieving remarkable decrease of the toxicity under ultrasonic vibration. This work provides deeper insights into photocatalytic materials in piezoelectric catalysis and advances the development of efficient piezoelectric catalysts for environmental applications.