Electric Field Assisted Femtosecond Laser Preparation of Au@TiO(2) Composites with Controlled Morphology and Crystallinity for Photocatalytic Degradation

TiO(2) is popular in photocatalytic degradation dye pollutants due to its abundance and its stability under photochemical conditions. Au loaded TiO(2) can achieve efficient absorption of visible light and deal with the problem of low conversion efficiency for solar energy of TiO(2). This work presents a new strategy to prepare Au nanoparticles-loaded TiO(2) composites through electric−field−assisted temporally−shaped femtosecond laser liquid-phase ablation of Au(3+) and amorphous TiO(2). By adjusting the laser pulse delay and electric field parameters, gold nanoparticles with different structures can be obtained, such as nanospheres, nanoclusters, and nanostars (AuNSs). AuNSs can promote the local crystallization of amorphous TiO(2) in the preparation process and higher free electron density can also be excited to work together with the mixed crystalline phase, hindering the recombination between carriers and holes to achieve efficient photocatalytic degradation. The methylene blue can be effectively degraded by 86% within 30 min, and much higher than the 10% of Au nanoparticles loaded amorphous TiO(2). Moreover, the present study reveals the crystallization process and control methods for preparing nanoparticles by laser liquid ablation, providing a green and effective new method for the preparation of high-efficiency photocatalytic materials.