Facile construction of a Mo-W18O49/CuO nanowire/nanoflower heterojunction for boosting photocatalytic nitrogen fixation

Photocatalytic nitrogen fixation is recognized as an environmentally friendly alternative to the traditional Haber-Bosch process for ammonia synthesis . In this paper, we synthesize W 18 O 49 /CuO nanowire/nanoflower type-II heterojunction using Cu mesh as substrate and Cu source by in situ etching and solvothermal method . The high-aspect-ratio W 18 O 49 nanowires self-assemble into a nanomesh , increasing the composite’s specific surface area and light refraction efficiency. Mo doping increases the oxygen vacancy concentration in the composite catalyst, enhancing its visible light absorption ability, promoting N 2 adsorption and activation at Mo-W active sites, and suppressing the recombination of photogenerated electrons and holes. Unlike conventional powder catalysts employed in suspension reaction system, we utilize substrate-supported catalysts in a more suitable liquid membrane reaction system. The 3 %Mo-W 18 O 49 /CuO/CM exhibits a significantly enhanced NH 4 + production rate of 9.071 × 10 −2 µmol/cm 2 /h, while retaining 81.2 % of its initial activity after 10 cycles experiments, demonstrating exceptional stability and recyclability.