ABSTRACT The electrocatalytic nitrogen oxidation reaction (eNOR) offers a sustainable route for nitrate (NO 3 ‒ ) synthesis, yet its practical application is limited by sluggish intermediate formation kinetics. Although •OH generated during water oxidation can promote the formation of the key * NOH intermediate, the cooperative mechanism between •OH and catalytic sites remains insufficiently understood. Herein, a spin‐state modulation strategy is proposed to enhance * NOH generation under simulated solar irradiation, thereby markedly improving the NO 3 ‒ yield and Faradaic efficiency (FE) of the eNOR. A heterojunction catalyst consisting of CoMo‐based layered double hydroxide nanosheets grown in situ on Ti 3 C 2 T x MXene (CoMo‐LDH@Ti 3 C 2 T x ) was developed to enable light‐assisted eNOR. The incorporation of Mo into Co‐LDH, together with the built‐in electric field of the heterojunction, enhances Mo–Co orbital hybridization and induces a spin‐state transition of Co 3+ centers from t 2g 6 e g 0 to t 2g 4 e g 2 configuration. This electronic regulation strengthens N 2 activation and accelerates * NOH formation via the cooperative involvement of two •OH radicals under illumination, thereby significantly boosting eNOR kinetics. Consequently, CoMo‐LDH@Ti 3 C 2 T x delivers NO 3 ‒ yield of 198.55 µg h −1 mg cat. −1 and FE of 46.22% under solar light, outperforming dark conditions and state‐of‐the‐art catalysts. These findings underscore the critical roles of spin‐state engineering and radical synergy in advancing sustainable nitrate production.
Zheng et al. (Sat,) studied this question.