Heterogeneous "Nanorust" containing cobalt oxide has been developed for the visible light assisted oxidation of thiols to disulfides using molecular oxygen as an oxidant under alkaline free conditions and therefore more environmental 10 freindly. Pyrolysis of heterogenized tetrasulfonated cobalt (II) phthalocyanine (CoPcS) supported on mesoporous ceria (CeO 2 ) transforms it into a novel heterogeneous "Nanorust" containing CoO x -C,N@CeO 2 which exhibited higher catalytic activity than the homogeneous CoPcS as well as ceria 15 immobilized CoPcS catalyst. Importantly, these catalysts could easily be recovered and recycled for several runs, which makes the process greener and cost-effective.