Femtosecond Laser Induced Phase Transformation of TiO₂with Exposed Reactive Facets for Improved Photoelectrochemistry Performance

Titanium dioxide (TiO2) is one of the most promising candidates for photoelectrochemistry applications. For a high photoelectrochemistry performance, the control of crystal structure and crystal facet is essential. The phase transformation of TiO2 is conventionally achieved by thermal annealing. Here, we report an approach for selective phase transformation of TiO2 containing exposed reactive facets with improved photoelectrochemistry performance. After femtosecond laser processing, TiO2 nanotubes with exposed reactive anatase {010} facets are prepared, and they have a maximum photocurrent density more than 5 times that of pure anatase. Additionally, this strategy can induce phase transformation in a selective area, which shows the advantages of patterning processing. Our method constructs a promising strategy for preparing functional nanomaterials with high performances and functionality.