In Situ Formation Of Anode Oxygen Evolving Catalysts And Their Properties

Hydrogen production by the electrochemical water splitting is an efficient method for storing non-grid-connected solar energy, wind energy and tidal energy. Extremely alkaline and high temperature conditions of traditional electrolytic cell will increase the corrosion speed and maintenance costs of the electrolytic cell. Near-neutral conditions will slow down the corrosion of the electrolysis device and make the electrolytic process more secure. An oxygen evolution catalyst is a promising anode material, which can be in situ formed and self-healing in mild near-neutral conditions.In this study, we developed novel Co-P, Ni-B and Ag-B oxygen evolution catalysts. The physical properties of obtained catalyst were characterized by SEM, EDS, XRD and XPS. The oxygen-evolving properties and stability of these catalysts were examined by variety of electrochemical methods. The main contents and results are listed as follows:Firstly, a Co-P oxygen evolution catalyst was electrodeposited in situ on the ITO electrode in a 0.1 mol/L KH2PO4+K2HPO4 (KPi) solution containing 1 mmol/L of Co(NO3)2 at pH 7.0 under 1 atm and room temperature. The catalyst was an verrucose material, it exhibits good catalytic activity and low oxygen evolution overpotential for electrolysis of water under mild conditions, an oxygen evolving overpotential of 385 mV at a current density of 1 mA/cm,Secondly, a Ni-B oxygen evolution catalyst was electrodeposited in situ on the ITO electrode in a 0.1 mol/L K2B4O7 solution containing 1 mmol/L of Ni(NO3)2 at pH 9.2 under 1 atm and room temperature. The catalyst was an amorphous material, it exhibits good catalytic activity and low oxygen evolution overpotential for electrolysis of water under mild conditions, an oxygen evolving overpotential of 310 mV at a current density of 1 mA/cm2.Finally, an Ag-B oxygen evolution catalyst was electrodeposited in situ on the ITO electrode in a 0.1 mol/L K2B4O7 solution containing 1 mmol/L of AgNO3 at pH 9.2 under 1 atm and room temperature. The catalyst was an elliptical flakes material, it exhibits good catalytic activity and low oxygen evolution overpotential for electrolysis of water under mild conditions, an oxygen evolving overpotential of 318 mV at a current density of 1 mA/cm2...