Novel ZnO/Ag6Si2O7 nanocomposites for activation of persulfate ions in photocatalytic removal of organic contaminants under visible light

In this study, ZnO/Ag6Si2O7 photocatalysts were prepared by refluxing method and used as visible-light responsive photocatalysts for the elimination of various organic contaminants in the existence of persulfate anions. The characteristic of as-prepared samples were investigated by XRD, UV-vis DRS, PL, EDX, FESEM, TEM, HRTEM, XPS, BET, EIS, photocurrent density, TGA, and Ft-IR instruments. Among the synthesized samples, the nanocomposite with 30% Ag6Si2O7 loading exhibited the greatest photocatalytic ability. Moreover, the removal rate constant of RhB by this nanocomposite in the presence of 0.74 EnM of persulfate ions was 214 x 10(-4)min(-1), which is almost 30.6, 6.11, 6.29, and 3.96-times premier than the pure ZnO, persulfate ions, ZnO/persulfate, and ZnO/Ag6Si2O7 (30%) nanocomposite, respectively. Lastly, the band alignments and the electrochemical behavior of the semiconductors were achieved and a mechanism for the boosted photocatalytic performances in the existence of persulfate ions was proposed using reactive species scavenging experiments. Also, the photocatalyst had high photostability after five repeated utilization.