Piezoelectric-driven hydrogen peroxide production and in-situ utilization for organic wastewater decontamination and synchronous disinfection: Efficacy, mechanisms and comprehensive assessments.

Hydrogen peroxide (H2O2) is a green oxidant with broad potential in organic wastewater treatment applications. However, conventional research typically examines either H2O2 generation or its specific utilization independently, lacking a comprehensive exploration of integrated mechanisms from production to practical application. To bridge this gap, this study introduced scalable and eco-friendly bismuth oxyhalide piezocatalysts to construct an integrated system for simultaneous H2O2 production and efficient in-situ utilization. Such a cleverly designed system exhibited exceptional piezocatalytic H2O2 production exceeding 710 μmol·g-1·h-1 via dual pathways, including water oxidation reaction (WOR) and oxygen reduction reaction (ORR). Life-cycle assessments and energy consumption analyses further validated the superior sustainability and efficiency of the proposed system compared to traditional piezoelectric catalysts. For direct applications of H2O2, the integrated system could achieve excellent performance in wastewater disinfection, demonstrating a 70.7 % antibacterial efficiency, and simultaneous decontamination with 94.7 % removal of sulfamethoxazole alongside a 10-fold kinetic enhancement compared to systems with externally added H2O2 systems. Moreover, in synergistic scenarios, combining H2O2 and periodate (PI) could effectively generate hydroxyl radicals (•OH) and singlet oxygen (1O2), achieving over 90 % removal efficiency for diverse refractory pollutants under complex water conditions (e.g., wide pH range 2.0-10.0, presence of coexisting anions and natural organic matter). The environmental safety of the constructed reaction system was further confirmed by a comprehensive toxicity assessment combining computational modeling with microbial and plant assays. This study bridges the existing gap between H2O2 generation and application, providing significant insights and advancing integrated water treatment strategies.