Promoting nitrogen photofixation over a periodic WS2@TiO2 nanoporous film

Abstract

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.