Boosting photocatalytic H2O2 production and non-biodegradable ofloxacin removal via a novel Ti3C2 MXene nanosheet-supported BiVO4/InVO4 Z-scheme heterojunction: Optimization and mechanism insights

Developing efficient dual-functional photocatalysts capable of simultaneously facilitating photocatalytic O₂ reduction for hydrogen peroxide (H₂O₂) production and organic pollutants degradation remains a significant challenge. Herein, a novel Ti₃C₂ MXene-supported BiVO₄/InVO₄ photocatalyst was synthesized via a facile hydrothermal method and evaluated for its visible-light-driven performance in ofloxacin (OFX) degradation and H₂O₂ generation. A design-of-experiments (DoE) approach was utilized to optimize key operational parameters of OFX degradation. Comprehensive structural, morphological, optical, and elemental characterizations confirmed that the Ti₃C₂ MXene scaffold significantly enhanced charge separation and transfer efficiency, while promoting strong visible-light absorption through the optimized band alignment between BiVO₄ and InVO₄. Under optimal RSM-CCD condition the optimized BIM 30 composite achieved a remarkable 99 % degradation efficiency of OFX (k = 0.08 min −1 ) and an 84.9 % reduction in TOC , demonstrating its superior mineralization capability. Concurrently, H₂O₂ production reached 838 μM within 60 min, which is approximately 15-fold higher than pristine BiVO₄ (56 μM) and 1.47-fold greater than the binary 40-BVO/InVO composite (568 μM), underscoring the enhanced photocatalytic performance of the ternary system . Mechanistic investigations identified that in the photocatalytic process, OH and O₂ − are the main active species. Molecular O₂ is predominantly reduced to H₂O₂ through a two-electron transfer pathway, with superoxide radicals serving as key intermediates. Furthermore, the QSAR analysis indicated a substantial reduction in the OFX toxicity and its degradation intermediates, confirming the environmental safety of the treated effluent. The BIM 30 composite depicted robust structural stability and reusability across multiple cycles, indicating its potential for long-term, sustainable applications. This study highlights the promising potential of MXene-supported heterojunctions as advanced multifunctional photocatalysts for dual green H₂O₂ generation and environmental remediation. • A novel Ti₃C₂ MXene-supported BiVO₄/InVO₄ Z-scheme heterojunction was synthesized. • BIM 30 achieved 99 % OFX degradation and 84.9 % TOC reduction under visible light. • H₂O₂ yield reached 838 μM, 15-fold higher than pristine BiVO₄, with excellent stability. • Reactive species ( OH, O₂ − ) dominated via a Z-scheme mechanism enhancing charge separation. • The catalyst showed broad-spectrum pollutant degradation and environmental safety.