Synergistic introduction of LSPR effect and Schottky junction: Cu@TiO2 charge regulation achieved efficient, stable photocatalytic removal

Abstract

Localized surface plasmon resonance (LSPR) and Schottky junction can effectively enhance the generation and separation efficiency of photogenerated carriers, but their synergistic effect has rarely been studied. Cu nanoparticles (Cu NPs) were utilized as a co-catalyst for forming Schottky junctions and induce plasma excitation. A simple molten-salt method was employed to prepare dispersed Cu NPs and stable oxygen vacancies (O_V). We achieved dual regulation of photogenerated carrier separation kinetics and catalytic sites. The synergistic effect of LSPR and Schottky junction enhanced the thermodynamics and kinetics of photocatalytic reactions, facilitating the generation of photogenerated carriers and driving the directional migration of these carriers. The dual-channel regulation mechanism significantly enhanced the photocatalytic efficiency of the catalysts. We revealed a significant enhancement in the photocatalytic efficiency of Cu₁₀@TiO₂, with a TC removal rate of 99.4% achieved within 25 min. The reaction rate was 3.12-times higher than that of pure TiO₂, and the enhanced performance remained stable even after multiple cycles. At the same time, the photocatalytic performances of catalysts were investigated in different water environments under various light sources. The as-prepared material maintained favorable photocatalytic activities in tap water, seawater, lake water, and pharmaceutical wastewater, which offers a promising opportunity to address real-life issues in sewage management. A facile and cost-effective method for preparing non-precious metal catalysts with the synergistic effects of LSPR and Schottky junction are presented in this work. This research boost the potential applications of TiO₂-based semiconductor materials in the removal of antibiotics from various water environments.