Dual-cocatalyst-promoted photocatalytic treatment of persistent waterborne pollutants via in situ MXene-derived TiO₂/Ti₃C₂ hybrids with plasmonic Ag nanoparticles

The integration of photocatalysts with MXenes and plasmonic metals has emerged as a promising strategy for enhancing wastewater treatment efficiency, leveraging the superior light-absorption and charge separation capabilities of these materials. In this study, we introduce an effective approach that significantly enhances the photocatalytic degradation of persistent organic pollutants by utilizing the synergistic benefits of dual cocatalysts: Ti₃C₂ (MXene) and Ag nanoparticles. We initially synthesized a series of TiO₂/Ti₃C₂ hybrids by annealing Ti₃C₂ at various temperatures, aiming to optimize the size, distribution, and integration of TiO₂ nanoparticles on a Ti₃C₂ substrate. These TiO₂/Ti₃C₂ hybrids were then decorated with Ag nanoparticles to induce the surface plasmonic resonance effect, known to amplify photocatalytic efficiency. Notably, the optimized hybrid Ag/TiO₂/Ti₃C₂ catalyst demonstrated significantly improved photocatalytic performance in degrading and mineralizing the persistent antibiotic sulfamethazine in water, outperforming TiO₂/Ti₃C₂ hybrids, anatase TiO₂, and other previously reported cutting-edge photocatalysts. This exceptional performance is primarily attributed to the synergistic effects of Ti₃C₂ and plasmonic Ag dual cocatalysts, which enhance optical absorption and specific surface area, as well as promote photoinduced charge transfer and separation. Additionally, the developed hybrids showed exceptional versatility in degrading various aqueous dye pollutants and maintained high efficacy across multiple cycles, underscoring their potential for recyclable and durable water-treatment applications. This work paves the way for the development of advanced MXene-based, plasmonically enhanced photocatalysts for the effective and sustainable treatment of waterborne pollutants.