ZnGaNO Photocatalyst Particles Prepared from Methane-Based Nitridation Using Zn/Ga/CO₃ LDH as Precursor

Methane-based nitridation was employed to produce wurtzite zinc-gallium oxynitride (ZnGaNO) photocatalyst particles using Zn/Ga/CO₃ layered double hydroxides (LDHs) as precursor. Introduction of methane to nitridation would promote the formation of Zn–O bonding and suppress shallow acceptor complexes such as V_(Zn)-Ga_(Zn) and Ga-O_i in ZnGaNO particles. On the other hand, high flow rate of methane would induce breaking of Ga–N bonding and enhance surface deposition of metallic Ga atoms. After loading with Rh and RuO₂, ZnGaNO particles had free electron density in an order of S50 > S20 > S90 > S0, which correlated well with their photocatalytic performance upon visible-light irradiation. The best performance of the loaded S50 was ascribed to the relatively flat surface band bending of the particle. Methane-based nitridation of Zn/Ga/CO₃ LDHs would provide a new route to tune the surface chemistry of ZnGaNO and enhance the photocatalytic performance to its full potential.