Plasmonic titanium nitride based ammonia synthesis by Photo-electrocatalytic reduction of nitrogen

Efficient and environmentally friendly production of ammonia (NH₃) remains a challenging objective. This study introduces graphitic carbon nitride (g-C₃N₄) supported by titanium nitride (TiN) nanojunction photo-electrocatalyst. In this research, TiN serves as a plasmonic-based broad-band light absorber, generating charge carriers that are harnessed for the nitrogen reduction reaction (NRR) in a highly efficient TiN/g-C₃N₄ nanohybrid. To enhance the NRR, the synthesized TiN/g-C₃N₄ is further modified with platinum (Pt) nanoparticles (NPs), forming a composite referred to as PTCN. The PTCN composite demonstrates outstanding performance in NH₃ production, exhibiting an impressive NH₃ production rate of 105 µg h⁻¹.mg^-1_cat. and a high faradaic efficiency of 36.4% in N₂-saturated aqueous electrolyte. To gain insights into the catalytic activity, density functional theory (DFT) calculations were employed to elucidate the underlying mechanism. The superior performance of the PTCN nanohybrid is attributed to the synergistic effects among the Pt NPs, TiN NPs, and g-C₃N₄ nanosheets. This research presents a promising avenue for ammonia production under ambient conditions, harnessing both solar and electric energy. The rational design of the TiN/g-C₃N₄ nanostructure, combined with the incorporation of Pt NPs, enables high catalytic performance, and offers a potential solution for environmentally friendly and efficient NH₃ production.