In this study, we developed methods for the one pot environmentally benign synthesis of benzimidazoles by cobalt ascorbic acid complex coated on TiO2 nanoparticles via aerobic photooxidative cyclization reactions. Easy work-up procedure, reusability of the catalyst and scalable to the multi-mole scale, which is valuable for an industrial process make these catalytic systems highly attractive. Also, the combination of photocatalytic and catalytic reactions presented here may help to develop a new strategy towards the development of photocatalysis-based organic synthesis.