TiO2 nanoparticles–reduced graphene oxide hybrid: an efficient and durable electrocatalyst toward artificial N2 fixation to NH3 under ambient conditions†
The Haber–Bosch process enables the industrial production of NH3 from N2 and H2, but it has problems with high energy consumption and CO2 emissions. Electrochemical reduction offers an environmentally-benign and sustainable alternative for NH3 synthesis. In this communication, we describe a TiO2 nanoparticles–reduced graphene oxide hybrid (TiO2–rGO) which behaves as an efficient non-noble-metal N2 reduction reaction (NRR) electrocatalyst for N2-to-NH3 conversion with excellent selectivity. When tested in 0.1 M Na2SO4, the TiO2–rGO achieves a high faradaic efficiency of 3.3% and a large NH3 yield of 15.13 μg h−1 mgcat.−1 at −0.90 V vs. a reversible hydrogen electrode. Notably, this catalyst also shows high electrochemical stability during electrolysis and recycling tests.