Titanium nitride nanoparticles for the efficient photocatalysis of bicarbonate into formate

Metallic nanoparticles can act as efficient photocatalysts thanks to the surface plasmons that they support, which are capable of harvesting light and generating hot carriers. Recently, titanium nitride (TiN) nanostructures have emerged as promising candidates for this application due to their much lower cost, and therefore greater sustainability, than structures made of noble metals, as well as their expected long-term thermal stability. In this work, we demonstrate that, under solar illumination, TiN nanoparticles, in combination with titanium dioxide (TiO2) nanostructures, can significantly increase the photocatalytic production of formate through the simultaneous photoreduction of bicarbonate and oxidation of glycerol. Importantly, we also show that TiN nanoparticles alone can provide an enhancement of the photocatalytic efficiently when compared to TiO2 nanocatalysts. Furthermore, by characterizing the morphology and material properties of the TiN nanoparticles after the reaction, we confirm that they remain stable under reaction conditions for extended periods of solar light exposure (8 hours). The results of this work advance our understanding of TiN nanoparticles as efficient photocatalysts and their use for the production of valuable chemicals.