Water splitting is promising to realize a hydrogenbased society.The key to improve the efficiency of water splitting is the catalyst.The practical use of molecular water-splitting catalysts relies on their integration onto electrode materials.We describe herein the immobilization of cobalt corroles on carbon nanomaterials with short conjugated linkers or with long alkane chains,or via π-π interactions or via simple adsorption.Carbon nanomaterials,particularly graphene and CNTs,are chosen as electrode materials because of their large surface areas,high electrical conductivities and chemical stabilities.The performance of the resulting hybrids for water splitting were detailedly compared in pH 0–14 aqueous solutions.All these hybrids are active for OER and HER.Blank carbon nanomaterials gave little currents under identical conditions.An activity trend is obtained for H2 and O2 evolution,showing the critical role of the axial ligand and electron transfer ability on electrocatalysis.Therefore,this work is significant to show potential uses of electrode materials with well-designed molecular catalysts in electrocatalysis.