A TaON nano-photocatalyst with low surface reduction defects for effective mineralization of chlorophenols under visible light irradiation

Abstract

TaON nanoparticles with low surface reduction defect sites were successfully constructed by a simple nitridation approach using Ta₂O₅·nH₂O as a precursor. Large amounts of crystal water in Ta₂O₅·nH₂O are considered as a parclose to prohibit Ta⁵⁺ from being reduced in the nitridation process with NH₃ gas. Urea was also used in the synthesis, acting as a co-nitridation agent together with NH₃ but also as a porogen for creating nanopores in TaON frameworks. The as-prepared TaON catalyst was evaluated by environmental purification of organic pollutants in water, as exemplified here by mineralization of phenol and its chloroderivatives in aqueous phase under visible light irradiation. Results revealed that a lower defect density of TaON, as well as its nanopore structure and smaller particle size, contribute to the promotion in both electron–hole separation and interfacial charge-transfer in materials surface/interface, being the main reasons for the enhanced photocatalytic performance.