The activation of Au–Ag plasmonic bimetallic nanocatalyst can make the nanocatalyst exhibit superior visible-light (VL) photocatalytic activity. An efficient activation of Au–Ag nanocatalyst by cold plasma requires the restructuring of Au and Ag species over catalyst surface to form Au–Ag alloy nanoparticles while suppressing agglomeration of the nanoparticles. We here report that the loading sequence of Au and Ag components on titanium dioxide (TiO₂) support during catalyst preparation and discharge atmosphere play important roles in the plasma activation. Preparation of AuAg/TiO₂ nanocatalyst by depositing Ag and Au in sequence could avoid the undesired loss of Ag component, and ensure an effective restructuring of Au and Ag species in O₂ plasma activation. Compared with the reductive (H₂) and inert (Ar and N₂) plasmas, discharge in oxidative O₂ establishes Coulomb field with the negatively charged species over catalyst surface and enable the restructuring and intimate interaction of Au and Ag species. The catalyst characterization and density functional theory calculations suggest that O₂ plasma endows AuAg/TiO₂ nanocatalyst with large numbers of Au–Ag alloy nanoparticles, small size of plasmonic nanoparticles, high density of coordinatively unsaturated sites, and high content of surface oxygen species in the activation, which facilitates the adsorption and activation of O₂, and thus CO oxidation reaction under VL irradiation.

Au-Ag等离子体双金属纳米催化剂的活化可以使纳米催化剂表现出优异的可见光（VL）光催化活性。冷等离子体对 Au-Ag 纳米催化剂的有效活化需要在催化剂表面重组 Au 和 Ag 物质以形成 Au-Ag 合金纳米粒子，同时抑制纳米粒子的团聚。我们在此报道，在催化剂制备和放电气氛期间，Au 和 Ag 组分在二氧化钛 (TiO ₂ ) 载体上的负载顺序在等离子体活化中起重要作用。通过依次沉积Ag和Au制备AuAg/TiO ₂纳米催化剂可以避免Ag组分的不希望损失，并确保Au和Ag物质在O _{2中的有效重组}等离子体活化。与还原性（H ₂）和惰性（Ar 和 N ₂）等离子体相比，氧化性 O ₂中的放电与催化剂表面上的带负电物质建立了库仑场，并使 Au 和 Ag 物质的重组和密切相互作用成为可能。催化剂表征和密度泛函理论计算表明，O ₂等离子体赋予了AuAg/TiO ₂纳米催化剂大量的Au-Ag合金纳米粒子、小尺寸的等离子体纳米粒子、高密度的配位不饱和位点和高含量的表面氧物种。活化，促进O _{2的吸附和活化}，因此在VL照射下发生CO氧化反应。