AbstractThe nanocomposites of metalloporphyrins and graphene oxide (GO) have been prepared and used for photodegradation of methylene blue (MB). The prepared nanocomposites have been characterized by SEM, IR, and UV-Vis. The results have shown that the binding mode of metalloporphyrins and GO is non-covalent bond. In order to study the photodegradation performance of nanocomposites, MB has been selected as the model organic pollutant to study the catalytic degradation efficiency of the composite under different light sources, and the photodegradation efficiency of metalloporphyrins and nanocomposites have been compared. The results have shown that the photocatalytic activity of metalloporphyrin/GO composites is better than that of the metalloporphyrin catalysts.