Template-free synthesis of Ta3N5 hollow nanospheres as a visible-light-driven photocatalyst

Ultrathin mesoporous Ta3N5 hollow nanospheres were synthesized via a facile and orchestrated template-free solution-based synthesis followed by thermal nitridation. A systematic investigation of structural evolution with annealing revealed a progressive crystallization with concurrent development of mesoporosity and modification of chemical composition with nitridation time. Subsequent performance of as-prepared photocatalysts were evaluated by the degradation of methylene blue under visible light irradiation (lambda > 400 nm). Ta3N5 hollow nanospheres exhibited higher photocatalytic activity than Ta3N5 nanorods or bulk Ta3N5, which can be attributed to their engineered structure as well as the oxygen and nitrogen content.