Photoelectrocatalytic oxidation of methanol over RuO2[sbnd]MnO2[sbnd]Co3O4 supported porous anatase under visible light irradiation.

Abstract Anatase supported heterogeneous photocatalyst consisting of RuO 2 , MnO 2 and Co 3 O 4 (1:13:13 ratio) was synthesized by a precipitation method and tested for photoelectrocatalytic (PEC) oxidation of methanol in 0.1 M KOH under visible light irradiation. The as-prepared photocatalyst was characterized by FTIR, UV–vis, XRD, Raman spectroscopy, FESEM/EDX, TEM, BET, XPS and TPR. The PEC studies by cyclic voltammetry indicated that the oxidation of methanol to CO 2 and H 2 O upon exposure to visible light occurs between 400 and 800 nm. The smaller value of the charge transfer resistance (R ct) of the RuO 2 MnO 2 Co 3 O 4 supported anatase TiO 2 electrode indicates a faster rate of charge transfer at the electrode-electrolyte interface compared to the Pt/C catalyst, which could be promising for direct methanol fuel cell application. Graphical abstract Image 1 Highlights • TiO 2 bandgap reduced and visible light absorption improved by addition of RuO 2 MnO 2 Co 3 O 4. • Formations of composite oxides onto TiO 2 decrease the e−-h+ recombination rates. • RuO 2 MnO 2 Co 3 O 4 are effective for visible light harvesting and charge separation. • RuO 2 MnO 2 Co 3 O 4 supported on TiO 2 oxidizes 4M methanol. • RuO 2 MnO 2 Co 3 O 4 supported on TiO 2 is suggested as an alternate for Pt/C. [ABSTRACT FROM AUTHOR]