Controllable nitridation of Ta2O5 in molten salts for enhanced photocatalysis

Pyrolysis of the Ta 2 O 5 /melamine mixture in molten chlorides is herein demonstrated as a facile and controllable method to nitridize and functionalize Ta 2 O 5 . The influence of the stoichiometry and composition of Ta 2 O 5 /melamine in molten salts on the nitridation process is rationalized to ensure the controllable preparation of Ta 3 N 5 and Ta 3 N 5 /TaON. The characterization results, including scanning electron microscopy, transmission electron microscopy, elemental mapping, X-ray photoelectron spectroscopy, and photoluminescence spectroscopy, all confirm the existence of the Ta 3 N 5 /TaON heterojunction, in which the TaON nanoparticles are closely anchored to the Ta 3 N 5 nanorods. Benefiting from its composition and structure, the Ta 3 N 5 /TaON composites show enhanced photocatalytic activity for the degradation of methylene blue. The present study highlights that the molten salt method using a solid nitrogen source can be a new technique for rationalizing the design of nitrides and oxynitrides.