Efficient Photocatalytic Nitrogen Fixation over Cuδ+‐Modified Defective ZnAl‐Layered Double Hydroxide Nanosheets

Abstract The photocatalytic reduction of nitrogen (N 2 ) with water (H 2 O) as the reducing agent holds great promise as a sustainable future technology for the synthesis of ammonia (NH 3 ). Herein, the effect of oxygen vacancies and electron‐rich Cu δ + on the performance of zinc‐aluminium layered double hydroxide (ZnAl‐LDH) nanosheet photocatalysts for N 2 reduction to NH 3 under UV–vis excitation is systematically explored. Results show that a 0.5%‐ZnAl‐LDH nanosheet photocatalyst (containing 0.5 mol% Cu by metal basis) affords a remarkable NH 3 production rate of 110 µmol g −1 h −1 and excellent stability in pure water. The X‐ray absorption spectroscopy, electron paramagnetic resonance, and density functional theory calculations reveal that Cu addition imparts oxygen vacancies and coordinatively unsaturated Cu δ + (δ < 2) with electron‐rich property in the ZnAl‐LDH nanosheets, both of which readily contribute to efficient separation and transfer of photogenerated electrons and holes and promote N 2 adsorption, thereby both activating N 2 and facilitating its multielectrons reduction to NH 3 .