Fundamentals and Recent Progress of Photocatalytic Nitrogen‐Fixation Reaction over Semiconductors

As a green energy carrier, a potential fuel and an essential chemical for the manufacturing of fertilizers, plastics, and explosives, ammonia (NH 3 ) is currently produced by Haber−Bosch process. However, the process converting nitrogen (N 2 ) into NH 3 under strict conditions consumes substantial energy and releases enormous greenhouse gases. In the context of the global energy crisis and increasing greenhouse effect, it is urgent to explore mild, green, sustainable, and economic nitrogen‐fixation strategies. Very recently, photocatalytic nitrogen‐fixation reactions, including nitrogen reduction reaction (NRR) and nitrogen oxidation reaction (NOR), have aroused widespread attention due to its environmental friendliness and cost‐effectiveness. To achieve high photocatalytic performance and selectivity, it is necessary to design photocatalyst and its photoreaction system reasonably to optimize the light absorption, charge separation, mass transport, adsorption, and activation of N 2 as well as proton/electron transfer. This review gives an overview of fundamentals, performance evaluation, and recent progress of the photocatalytic nitrogen‐fixation reactions. The photocatalysts and their design strategies are classified, and several suggestions are given for the analysis of the existing photocatalytic nitrogen‐fixation systems. Finally, a short perspective on the existing challenges and future opportunities are outlined for providing insights into the development of high‐efficiency photocatalytic systems for artificial N 2 fixation.