Plasmonic Titanium Nitride/g-C₃N₄ with Inherent Interface Facilitates Photocatalytic CO₂ Reduction

Plasmonic metal nitride is a practical alternative for plasmonic gold nanoparticles owing to its low-cost, tunable plasmonic resonance in the visible-light and near-IR region. However, an efficient charge transfer between plasmonic metal nitride nanoparticles and graphitic carbon nitride g-C3N4 through the formation of chemical bonds remains challenging. Herein, a facile strategy for the fabrication of plasmonic titanium nitride/g-C3N4 with intimate contact toward an enhanced photocatalytic CO2 reduction is proposed. The functionalization of TiN nanoparticles with amino groups enables the copolymerization with g-C3N4 precursors, offering intimate contact between them by the covalent bonds. This intimate contact could facilitate the electron transfer between TiN nanoparticles and g-C3N4. Under optimized conditions, the representative g-C3N4-2.8TiN has the highest CO production rate of ∼820 μmol g–1 h–1 with an apparent quantum yield of 3.5% at 400 nm and even 0.43% at 550 nm, which are some of the highest reported values for g-C3N4-based materials. This work offers promising opportunities to fabricate low-cost plasmonic nanoparticle/semiconductor systems for solar energy applications.