Rational Design of TiO 2 /CuS Heterojunction Nanocoatings for Dual-Functional Self-Cleaning Textiles with Photocatalytic-Photothermal Performance

Abstract

Although titanium dioxide nanoparticles (TiO2 NPs) are superb UV photocatalysts, their practical use is limited by the low (~5%) solar UV content. Herein, TiO2/CuS heterojunction nanoparticles were constructed via in-situ synthesis, which exhibits a significantly reduced bandgap of 2.64 eV and consequently achieves broad absorption from the UV to the visible light region. The optimized heterojunction (3:1) demonstrated a photocatalytic efficiency 9.8 times that of pristine TiO2, achieving 80% degradation of RhB under visible light, compared to merely 17% by TiO2 alone. Moreover, the heterojunction exhibited superior photothermal response speed, reaching 105 °C within 14 seconds under 980 nm NIR irradiation, which far surpassed the heating capability of pure CuS (67.2 °C) and TiO2 (36.8 °C). The heterojunction-functionalized cotton and polypropylene nonwoven fabrics retained visible-light photocatalytic activity (60% RhB degradation), and maintained ~53% nanoparticle loading after 5 washing cycles, demonstrating practical durability. This work establishes a scalable platform for solar-driven functional textiles by precisely designing heterostructures that concurrently enable efficient photocatalytic decontamination and rapid photothermal response with robust durability suitable for practical applications.