Efficient Solar-Driven Nitrogen Fixation over Carbon-Tungstic-Acid Hybrids.

Ammonia synthesis under mild conditions is of supreme interest. Photocatalytic nitrogen fixation with water at room temperature and atmospheric pressure is an intriguing strategy. However, the efficiency of this method has been far from satisfied for industrialization, mainly due to the sluggish cleavage of the N≡N bond. Herein, we report a carbon-tungstic-acid (WO3 ⋅H2 O) hybrid for the co-optimization of N2 activation as well as subsequent photoinduced protonation. Efficient ammonia evolution reached 205 μmol g-1  h-1 over this hybrid under simulated sunlight. Nitrogen temperature-programmed desorption revealed the decisive role of carbon in N2 adsorption. Photoactive WO3 ⋅H2 O guaranteed the supply of electrons and protons for subsequent protonation. The universality of carbon modification for enhancing the N2 reduction was further verified over various photocatalysts, shedding light on future materials design for ideal solar energy utilization.