Promoting nitrogen photofixation over a periodic WS2@TiO2 nanoporous film

Atmospheric nitrogen fixation using a photocatalytic system is a promising approach to produce ammonia. However, most of the recently explored photocatalysts for N2 fixation are in the powder form, suffering from agglomeration and difficulty in the collection and leading to unsatisfactory conversion efficiency. Developing efficient film catalysts for N2 photofixation under ambient conditions remains challenging. Herein, we report the efficient photofixation of N2 over a periodic WS2@TiO2 nanoporous film, which is fabricated through a facile method that combines anodization, E-beam evaporation, and chemical vapor deposition (CVD). Oxygen vacancies are introduced into TiO2 nanoporous films through Ar annealing treatment, which plays a vital role in N2 adsorption and activation. The periodic WS2@TiO2 nanoporous film with an optimized WS2 content shows highly efficient photocatalytic performance for N2 fixation with an NH3 evolution rate of 1.39 mmol g−1 h−1, representing one of the state-of-the-art catalysts.