Enhanced plasmonic photocatalytic performance of C doped TiN nanocrystals through ultrathin carbon layers

Carbon-doped TiN nanoparticles on an ultrathin carbon layer, were successfully used for photocatalytic dye degradation synthesised by a simple calcination process. The resulting catalyst exhibited remarkable plasmonic photocatalytic performance under visible light irradiation. In comparison with benchmark rutile TiO₂ and g-C₃N₄/TiO₂ heterostructure catalysts, the first-order reaction rate constant of the developed catalyst improved approximately 34.2 and 6.5 times, respectively. The doping concentration of carbon and the crystal size of TiN nanoparticles, predominantly influenced by the amount of urea and calcination temperature, were identified as crucial factors governing the plasmonic photocatalytic activity. Density functional theory (DFT) calculations indicated that the introduction of carbon-sp bands into the TiN band structure promoted interband excitation of electrons and facilitated the generation of hotter holes, thereby enhancing the degradation of dyes and ultimately contributing to the superior photocatalytic activity observed.