Electronic and Interface Regulation of Wurtzite Surfaces Promotes Photocatalytic Ammonia Synthesis under Visible Light Irradiation

Achieving efficient photocatalytic ammonia synthesis under mild conditions provides a sustainable approach for producing nitrogen-containing resources. The current challenge is to find ideal photocatalysts with strong N2 activation capacity and superior interfacial charge transfer. Herein, we report that efficient photocatalytic ammonia synthesis can be achieved across the entire visible light region over Ti-doped defective ZnO1–x with Ru cocatalyst loading. Due to the presence of local electrostatic fields and unique surface structures, the Ti atoms doped on the nonpolar (100) facets of ZnO1–x trigger the most strong activation of N2 with excellent electron back-donation power, resulting in an unprecedented elongation of N≡N bonds, from the original 1.117 to 1.328 Å, as well as one-electron reduction of N2 to N2–. The supported Ru cocatalyst enables the upward band bending of ZnO and the formation of interfacial Schottky contacts, simultaneously enhancing the reduction potential of photogenerated electrons and minimizing electron–hole recombination, which further promotes the efficiency of ammonia synthesis.