Near-infrared driven N 2 fixation on ZnO–MXene (Ti 3 C 2 ) heterostructures through pyroelectric catalysis

Temperature fluctuations caused by sunlight represent a form of low-quality thermal energy that is generally insufficient for driving chemical reactions. Here, we designed a ZnO–MXene (Ti 3 C 2 ) heterostructure catalyst, which can harvest solar near-infrared (NIR) energy to drive the sluggish ammonia production reaction using water and N 2 as the feedstock. Our research confirmed that ammonia was produced through a pyroelectric process, rather than a photocatalytic process. The ZnO–MXene heterostructure with ∼20 wt% of Ti 3 C 2 exhibited a 6.5-fold improvement in activity compared to bare ZnO. The Ti 3 C 2 not only harvests NIR energy to heat up the pyroelectric ZnO, but also traps the pyro electrons from ZnO and co-catalyzes the reduction of N 2 to ammonia. This work offers a novel strategy for ammonia production utilizing the abundant solar NIR energy under ambient conditions.