Promoted Fixation of Molecular Nitrogen with Surface Oxygen Vacancies on Plasmon-Enhanced TiO2 Photoelectrodes.

A hundred years on, the energy-intensive Haber-Bosch process continues to turn the N2 in air into fertilizer, nourishing billions of people while causing pollution and greenhouse gas emissions. The urgency of mitigating climate change motivates society to progress toward a more sustainable method for fixing N2 that is based on clean energy. Surface oxygen vacancies (surface Ovac ) hold great potential for N2 adsorption and activation, but introducing Ovac on the very surface without affecting bulk properties remains a great challenge. Fine tuning of the surface Ovac by atomic layer deposition is described, forming a thin amorphous TiO2 layer on plasmon-enhanced rutile TiO2 /Au nanorods. Surface Ovac in the outer amorphous TiO2 thin layer promote the adsorption and activation of N2 , which facilitates N2 reduction to ammonia by excited electrons from ultraviolet-light-driven TiO2 and visible-light-driven Au surface plasmons. The findings offer a new approach to N2 photofixation under ambient conditions (that is, room temperature and atmospheric pressure).