Ag₃PO₄ Nanoparticles Decorated Carbon Nitride Nanotube to Boost Visible‐Light Photocatalytic Activity for the Degradation of Azo Dyes

Abstract

An efficient and stable photocatalyst consisting of Ag 3 PO 4 nanoparticles coupled with carbon nitride nanotubes (G-C 3 N 4 ) for the degradation of azo dyes was firstly prepared by in-situ deposition method. The Ag 3 PO 4 decoration significantly improved the photocatalytic activity of G-C 3 N 4 , in which Ag 3 PO 4 / G-C 3 N 4 with mass ratio of 15 % could achieve the degradation efficiency of 95 % within 20 min. And the kinetic constant of degradation reaction was up to 0.14 min À 1 , which has around 22.5 times enhancement compared with that of G-C 3 N 4 . The heterojunction between Ag 3 PO 4 and G-C 3 N 4 accelerates the efficient separation and transfer of photogenerated charge carriers, and the Ag nanoparticles verified to be generated by the photoreduction of Ag 3 PO 4 can also act as an internal channel to promote the charge transport. In addition, the effect of the concentration of both catalyst and dye on the photocatalytic activity was further investigated. The proposed Zscheme catalytic mechanism of the composite photocatalyst was also proved.

Preparation of Ag3PO4tetrapods anchored to nitrogen-doped carbon quantum dots for enhanced photocatalytic performance

“…The NCQDs(0.75%)/Ag 3 PO 4 has a lower recombination rate of carriers because of its weaker intensity. 48 As can be seen from Fig. 6(d) and Table S1 (ESI †), the timeresolved transient fluorescence plots demonstrate that the separation efficiency of photo-generated carriers has been strengthened.…”

“…The NCQDs(0.75%)/Ag 3 PO 4 has a lower recombination rate of carriers because of its weaker intensity. 48…”

“…The conduction band (CB) edge (E CB ) can be computed by eqn (5): 51 Paper NJC Thus, the conduction band edge of pure Ag 3 PO 4 tetrapods and NCQDs can be counted at about À0.04 eV and À2.71 eV, respectively. There is no doubt that the conduction band position of pure Ag 3 PO 4 (À0.04 eV) would not be more negative than the standard reduction potential of O 2 / O 2 À (À0.33 eV), 48 thus the e À in the CB of the Ag 3 PO 4 tetrapods is thermodynamically unable to restore the O 2 to O 2 À . Therefore, the NCQDs might provide a suitable CB position for reducing the O 2 to O 2 À .…”