Uranyl ions anchored within the mesopores of MCM-41 silicate host matrix served as highly efficient heterogeneous catalysts for sunlight-assisted room-temperature photooxidation of methane in the presence of air to selectively form carbon dioxide. The extent of conversion depended upon the methane content; lower the concentration, faster was the completion of reaction. It was also confirmed that no thermocatalytic reaction occurred below 200°C in the absence of radiation, other test conditions remaining the same. These results are of relevance from the point of view of abatement of VOCs in the environment.