In-liquid femtosecond laser-engineered dual-type cation and anion vacancies boost photocatalysis

This is the authors' abstract. We don't add key points for this paper.

Surface vacancy engineering is crucial for enhancing charge separation in catalytic reactions. Traditional approaches have largely focused on single-type vacancies that trap either electrons or holes, limiting the effectiveness of overall redox reactions. Constructing dual-type metal-oxygen vacancies (V M -V O ) facilitates trapping electrons and holes simultaneously and selectively. However, it poses significant challenges under equilibrium conditions due to the incompatible vacancy-formed conditions. Here, we utilize the non-equilibrium effect of the femtosecond-laser-processing technique to construct surface V M -V O . Taking TiO 2 as a model, we confirm the surface engineering of dual-type titanium and oxygen vacancies (V Ti -V O ), synergistically boosting charge lifetime from 281.4 ps to 1507.6 ps, by 5.4 times. Remarkably, a dramatic enhancement of the apparent quantum efficiency in photocatalytic hydrogen evolution from 12.4% to 80.7% under 365 nm illumination is achieved. This work demonstrates a non-equilibrium femtosecond laser processing strategy for accurately carving V M -V O on metal oxides and highlights the significantly enhanced photocatalysis empowered by V M -V O -induced charge separation.