High‐Performance Nitrate Photoreduction to Ammonia on Organic Photovoltaic Heterojunction Nanoparticles

Photocatalytic nitrate reduction to ammonia (NO 3 RR) could alleviate the energy/environmental burdens associated with Haber‐Bosch process, however, still suffers from insufficient visible‐light utilization and low ammonia production rate. Herein, we present the first case of photocatalytic NO 3 RR using a platinum‐loaded organic photovoltaic heterojunction nanoparticle (OPV‐NP) as photocatalysts. The donor/acceptor interpenetrating network inner OPV‐NPs overcomes the limitation of intrinsically short exciton diffusion length of organic photosensitizers. By delicately tuning the chemical/topological structure of near‐infrared acceptors, the intermolecular packing strength and crystalline ordering are improved greatly, thus driving the more efficient generation/transport of charge carriers and ammonia production. As a result, the optimized OPV‐NPs achieves a first‐class photocatalytic ammonia production rate of 6.79 mmol g −1 h −1 and excellent operational stability during 40 h continuous photocatalysis under AM 1.5G simulated sunlight. This work not only highlights the considerable potential of OPV‐NPs in photocatalytic NO 3 RR but also provides valuable insights for rational material design in such a promising photocatalytic system.