Ag-Doped g-C3N4 film electrode: fabrication, characterization and photoelectrocatalysis property

Ag-Doped graphitic carbon nitride films (Ag/g-C3N4) were synthesized easily onto ITO substrates by a liquid-based reaction process. Ag/g-C3N4 films were comprehensively characterized by SEM, HRTEM, XRD, UV/vis DRS, and XPS. The results indicated that Ag and Ag2O disperse homogeneously in the matrix of the g-C3N4 film. The photocurrent response of the Ag/g-C3N4 films increased remarkably with increasing Ag content and the best performance was observed with the sample of Ag/g-C3N4 (1 : 10). The Ag/g-C3N4 films exhibited a high photoelectrocatalytic activity for the degradation of methylene blue. The enhancement of photoelectrocatalysis owing to more visible light could be harvested and photogenerated electron and interfacial electron could transfer more easily after modifying Ag in the g-C3N4 film. Thus, a possible photoelectrocatalysis mechanism was proposed. Beside g-C3N4, electron-hole pairs could be generated by Ag under visible light irradiation, and the photogenerated electron was captured by O2 or &z.rad; O2- and then forms &z.rad; OH radicals.