Wastewater containing graphene oxide (GO) has become important industrial wastewater due to a sharp increase in graphene oxide production in recent years. In this paper, SnO2 and TiO2 were added into aqueous suspensions of GO to degrade GO particles under UV light irradiation. Dosages of added metal oxides, pH values of the reaction mixture and UV irradiation in photo-degradation procedure were optimized. Photoluminescence and electrochemical impedance spectroscopy spectra were determined to study on separation and transfer of photo-generated electron-hole pairs at the GO/metal-oxide interfaces. Experimental results showed that GO particles were adsorbed on the surface of SnO2 or TiO2 particles via electrostatic attraction. SnO2 (conduction band bottom energy level (EC) = −5.00 eV) and TiO2 (EC = −4.05 eV) were effective photo-catalysts for degrading GO to give CO2 and H2O. Effective photo-catalytic degradation of GO would be contributed to EC values of SnO2 (−5.00 eV) and TiO2 (−4.05 eV) being lower than the lowest unoccupied molecular orbital energy level (ELUMO) value of GO (−3.59 eV). Therefore, metal oxides with low EC values (< −3.59 eV) would be selectable catalysts for degrading GO in wastewater. Similarly, if an EC value of a metal oxide was lower than the ELUMO value of an organic pollutant, the metal oxide would be selectable catalysts for degrading the pollutant in wastewater.