Nano-titania (TiO₂) has drawn considerable attention for decades for its excellent photocatalytic activity. The use of photocatalyst TiO₂ in the form of surface coating is usually desired for long-term recyclable photocatalytic performances. Yet deposition of the coatings with appropriate nanostructures persists challenging. Thermal spray processing usually triggered loss of photocatalytic anatase in the coatings. To retain anatase structure from starting TiO₂ powder, in this study, cold spray was employed to deposit TiO₂ nanostructured coatings using TiO₂ nanoparticles as the starting feedstock. The mechanically blended Al-7.5 wt.% TiO₂ powder was used as the feedstock for the coating fabrication, and Al was used as the binder for the nano-TiO₂ particles. The coatings containing anatase phase were successfully fabricated and showed good long-term recyclable performance and service life. After methylene blue degradation testing for three times, the photocatalytic efficiency of the coatings still remained over 90% of the initial photocatalytic efficiency. After high-pressure gas purge and flame sweep processing, the coatings retained the initial nanostructures at their surfaces. The cold spray technical route might open a new window for making the coatings of temperature-sensitive nanosized particles for functional applications.

数十年来，纳米二氧化钛（TiO ₂）以其出色的光催化活性备受关注。为了长期可回收的光催化性能，通常期望使用表面涂层形式的光催化剂TiO ₂。然而，具有合适的纳米结构的涂层的沉积仍然具有挑战性。热喷涂工艺通常会导致涂层中光催化锐钛矿的损失。为了保留起始TiO ₂粉末的锐钛矿结构，在这项研究中，采用TiO ₂纳米颗粒作为起始原料，采用冷喷涂法沉积了TiO ₂纳米结构涂层。机械混合的Al-7.5 wt。％TiO ₂粉末用作涂料制造的原料，Al用作纳米TiO ₂颗粒的粘合剂。包含锐钛矿相的涂料已成功制备，并显示出良好的长期可回收性能和使用寿命。在进行三次亚甲蓝降解测试后，涂层的光催化效率仍保持在初始光催化效率的90％以上。经过高压气体吹扫和火焰吹扫处理后，涂层在其表面保留了初始纳米结构。冷喷涂技术路线可能会开辟一个新窗口，为功能性应用生产对温度敏感的纳米颗粒涂层。