CuO@C exhibits a particle size of 36-123 nm . It can be used as an antifungal agent against Alternaria alternata, Fusarium oxysporum, Penicillium digitatum, and Rhizopus oryzae with inhibition zones of 36, 20.2, 16, and 10.2 mm, respectively . CuO@C was also used as a photocatalyst for pharmaceuticals e.g. paracetamol degradation . It offered an efficiency of 95% within 60 min . It can also be used for the reduction of 4-nitrophenol into 4-aminophenol . In the presence of NaBH4, CuO@C undergoes catalytic degradation of organic dyes .