Developing a Hybrid Photocatalyst by Laser Embedding in Liquid: Case Study on Ag-Doped TiO₂ Nanocrystal

In catalytic fields, purposely optimizing the crystalline structure of semiconductor photocatalysts to enhance photogenerated carrier activity is a key strategy for advanced oxidation processes (AOP). Constructing hybrid nanospheres with synergistic effects is effective, as noble metal nanospheres benefit from localized surface plasmon resonance (LSPR) and large specific surface area for visible-light harvesting. However, the neat, facile and efficient embedding of noble metal spheres into semiconductors remains challenging. In this work, a novel approach of laser embedding in liquid (LEL) is designed to combine Ag and TiO₂ spherical nanocrystals. Under the powerful photothermal effect between laser heating and colloidal particles quenching in liquid, the Ag components can be successfully embedded in the TiO₂ surface area to produce the spherical Ag/TiO₂ nanocomposites (NCs). After this modification, an excellent photocatalytic performance was achieved. Compared with the raw TiO₂, 2.73- and 2.93-fold enhancements were achieved in Ag/TiO₂ NCs at Ag: TiO₂ mass ratios of 1:4 and 2:3, respectively. The possible enhancement mechanism was proposed by determination of the different reactive radicals in the Ag/TiO₂ NCs. This work proposes an in-depth understanding of the spherical nanocrystal structural mechanism design by laser-induced manufacturing and offers a reference for the performance optimization of metal-based AOP photocatalysts.