The cobalt phosphate-/cobalt borate-based oxygen-evolving catalysts （OECs） are the important class of earth-abundant electrocatalysts that can operate with high activity for water splitting under benign conditions. ...The cobalt phosphate-/cobalt borate-based oxygen-evolving catalysts （OECs） are the important class of earth-abundant electrocatalysts that can operate with high activity for water splitting under benign conditions. This article reports the integration of cobalt phosphate （Co- Pi） and cobalt borate （Co-Bi） OECs with three-dimensional （3D） graphene foam （GF） for the electrocatalytic water oxidation reaction. The GF showed a unique advantage to serve as a highly conductive 3D support with large capacity for anchoring and loading Co-OECs, thereby facilitating mass and charge transfer due to the large amount of active sites provided by the 3D graphene scaffold. As a result, this integrated system of GF and Co-OECs exhibits synergistically enhanced catalytic activity. The overpotential （η） of Co-Pi and Co-Bi/graphene catalysts is about 0.390 and 0.315 V in neutral solutions, respectively. Besides, the integrated Co-OECs/graphene catalysts have also exhibited improved and stable oxygen evolution catalytic ability in alkaline solution.展开更多
基金supported by the National Natural Science Foundation of China(21322304,11290161)the National Basic Research Program of China(2012CB933003,2013CB932603)
文摘The cobalt phosphate-/cobalt borate-based oxygen-evolving catalysts （OECs） are the important class of earth-abundant electrocatalysts that can operate with high activity for water splitting under benign conditions. This article reports the integration of cobalt phosphate （Co- Pi） and cobalt borate （Co-Bi） OECs with three-dimensional （3D） graphene foam （GF） for the electrocatalytic water oxidation reaction. The GF showed a unique advantage to serve as a highly conductive 3D support with large capacity for anchoring and loading Co-OECs, thereby facilitating mass and charge transfer due to the large amount of active sites provided by the 3D graphene scaffold. As a result, this integrated system of GF and Co-OECs exhibits synergistically enhanced catalytic activity. The overpotential （η） of Co-Pi and Co-Bi/graphene catalysts is about 0.390 and 0.315 V in neutral solutions, respectively. Besides, the integrated Co-OECs/graphene catalysts have also exhibited improved and stable oxygen evolution catalytic ability in alkaline solution.
