Construction of fiber-shaped silver oxide/tantalum nitride p-n heterojunctions as highly efficient visible-light-driven photocatalysts.

Constructing novel and efficient p-n heterojunction photocatalysts has stimulated great interest. Herein, we report the design and synthesis of fiber-shaped Ag2O/Ta3N5p-n heterojunctions as a kind of efficient photocatalysts. Ta3N5 nanofibers were prepared by an electrospinning-calcination-nitridation method, and then the in-situ anchoring of Ag2O on their surfaces was realized by a facile deposition method. The resulting Ag2O/Ta3N5 heterojunctions were comprised of porous Ta3N5 nanofibers (diameter: ∼150nm) and Ag2O nanoparticles (size: ∼12nm). The photocatalytic activity of these heterojunctions were studied by decomposing rhodamine B (RhB) dye and tetracycline (TC) antibiotic under visible light (λ>400nm). In all the samples, the heterojunction with Ag2O/Ta3N5 molar ratio of 0.2/1 displays the best activity. It is found that a synergistic effect contributes to the effective suppression of charges recombination between Ta3N5 and Ag2O, leading to an enhanced photocatalytic activity with good stability. The photogenerated holes (h+) and superoxide radicals (O2-) play dominant roles in the photocatalytic process. These p-n heterojunctions will have great potential for environmental remediation because of the facile preparation process and exceptional photocatalytic activity.