Interface engineered Sb2O3/W18O49 heterostructure for enhanced visible-light-driven photocatalytic N2 reduction

The direct photochemical N 2 reduction reaction boasts the potential for clean and sustainable NH 3 manufacturing, yet achieving this remains a significant challenge. To activate and cleave the nonpolar N≡N bond and accelerate the transport and separation of charge carriers during photocatalysis , the design and facile synthesis of active, robust, cheap, and earth-abundant photocatalysts is crucial. Here, we demonstrate efficient and stable visible light fixation of N 2 to NH 3 by constructing a novel heterostructure consisting of two-dimensional Sb 2 O 3 nanosheets and one-dimensional W 18 O 49 nanowires . A remarkable NH 3 production rate of up to 731 μg NH3  h −1  g cat. −1 is attained in visible light over the nanocomposite without cocatalyst, 5.5-fold and 3.4-fold improvement over that of discrete Sb 2 O 3 and W 18 O 49 respectively, which also significantly exceeds many previous reported photocatalytic systems. The superior photocatalytic performance can be attributed to the unique structure of the composites, which provides ample exposed surface catalytic sites with a high density of oxygen vacancies, promoting the adsorption and activation of N 2 molecules to form *NNH. Equally importantly, the interface between Sb 2 O 3 and W 18 O 49 greatly facilitates charge carrier migration and separation. Further density functional theory calculations manifest that the interfacial metal sites on Sb 2 O 3 /W 18 O 49 serve as the main active centers which possess a strong donating electron ability to the empty N 2 antibonding orbitals to trigger the following NH 3 synthesis. This work provides a simple and effective method to modify metal oxides for enhancing N 2 photofixation.