Recent Advances in Solar Photo(electro)catalytic Nitrogen Fixation

Ammonia (NH₃) is an essential chemical in modern society. It is currently produced in industry by the Haber-Bosch process using H₂ and N₂ as reactants in the presence of iron-based catalysts at high-temperature (400e600 °C) and extremely highpressure (20e40 MPa) conditions. However, its efficiency is limited to 10%e15%. At the same time, a large amount of energy is consumed, and CO₂ emission is inevitably. The development of a sustainable, clean, and environmentally friendly energy system represents a key strategy to address energy crisis and environmental pollution, ultimately aiming to achieve carbon neutrality. Within this framework, semiconductor photocatalytic nitrogen fixation leverages green and pollution-free solar energy to produce NH₃ d an essential chemical raw material. This innovative process offers a sustainable alternative to the conventional chemical NH₃ production method that involves tremendous energy consumption and environmental pollution. Herein, this review provides a comprehensive overview of the photo(electroc)catalytic nitrogen fixation reaction, covering influencing factor, experimental equipment of photocatalysis, electrocatalysis and photoelectrocatalysis, characteristics, and reaction mechanism. Particularly, recent advances in semiconductor photocatalyst, photo(electro)catalytic nitrogen fixation system, and photo(electro)catalytic nitrogen fixation mechanism are discussed. Future research directions in solar photo(electro) catalytic nitrogen fixation technology are also outlined.