Charge separation and transport of the photo-generated electrons and holes form the basis to determine the kinetics of photocatalytic reactions. In the present work, the photo-generated electron is readily pulled from the photoactive catalyst by an electron sink (graphene) and transported to a site where the oxygen reduction reactions take place at a higher rate owing to better adsorption of other co-catalyst (gamma-alumina). In this dual electron-cocatalyst modified TiO2-Al2O3-rGO photocatalyst, rGO works as the electron mediator, and Al2O3 surface acts as the electron reduction site. The synergistic effect of rGO, and Al2O3 as bi-cocatalysts showed higher photocatalytic performance than bare TiO2, TiO2-Al2O3 and TiO2-rGO. This emphasizes the importance of both cocatalysts in electron separation and transfers where a single cocatalyst finds it difficult to carry out the crucial functions simultaneously. The modified TiO2-Al2O3-rGO photocatalyst under solar light reported 76% degradation of phenol in 5 h for 100 mg/L initial concentration. Results suggest that the presence of defects promote theoxygen reduction reactions (ORR) activity on the catalyst (TiO2-Al2O3-rGO) surface. The work also provides some insights to design high-efficiency solar propelled photo-catalysts based on work function theory.