Synthesis of flower-like Ta3N5-Au heterojunction with enhanced visible light photocatalytic activity

Abstract

Ta3N5-Au heterojunction was prepared via a facile solvothermal precipitation-nitridation-wet impregnation method. Ta3N5-Au consisted of Ta3N5 microspheres (diameters: 1–2.5 μm) and Au nanoparticles (size: ∼3.5 nm). Ta3N5 microsphere was composed of nanorods (diameter: 20–30 nm; length: 400–500 nm), and Au nanoparticles were well-dispersed on the surface of Ta3N5 nanorods. Photocatalytic performances of as-prepared catalysts were evaluated by the degradation of MB, RhB or 4-CP under visible light irradiation (λ > 400 nm), flower-like Ta3N5-Au exhibited higher photocatalytic activity than flower-like Ta3N5, bulk Ta3N5 or Ta3N5-Au. The enhanced photocatalytic activity of Ta3N5-Au could be attributed to the synergistic effect of high surface area and efficient separation of photogenerated charge carriers. The photogenerated holes (h+) and superoxide radical anions (O2−) were found to be the leading active species responsible for the degradation of RhB dye. The cycling experiments demonstrated that flower-like Ta3N5-Au had good recyclability.