Ag/Ag_xH_3–xPMo₁₂O₄₀ Nanowires with Enhanced Visible-Light-Driven Photocatalytic Performance

Photocatalysis, a promising technology platform to address the environmental problems, has been attracting considerable attention. In this paper, Ag / Ag x H 3– x PMo 12 O 40 (simplified as Ag / AgHPMo 12 ) nanowires have been synthesized by a facile solid reaction route and in situ photodeposited method. The results of SEM and TEM indicate that the diameters of AgHPMo 12 nanowires are about 45 ± 10 nm, and Ag nanoparticles with diameters in the range of 5–15 nm are uniformly anchored on the surface of AgHPMo 12 nanowires. The Ag content in the Ag/AgHPMo 12 composite was manipulated by the light irradiation time (Ag/AgHPMo 12 - x; x stands for the irradiation time; x = 2, 4, 6, 8 h, respectively). With increasing irradiation time, the light absorption of as-synthesized samples in the visible region was gradually enhanced. The Ag/AgHPMo 12 -4 exhibits the best photocatalytic performance for the degradation of methyl orange and reduction of Cr 2 O 7 2– under visible-light (λ > 420 nm) irradiation. The study of the photocatalytic mechanism reveals that both Ag and AgHPMo 12 can be excited by visible light. The photoinduced electrons were transferred from AgHPMo 12 to metallic Ag, and combined with the Ag plasmonic holes. The Ag plasmonic electrons were trapped by O 2 to form ·O 2 –, or directly reduced Cr 2 O 7 2– to Cr 3+ . Meanwhile, the ·O 2 – species and the photogenerated holes of AgHPMo 12 were used to oxidize MO or i -PrOH; thus, they showed highly efficient and recyclable photocatalytic performance for removing the organic and inorganic pollutants.