Synthesis of CaMn_2O_4-related electrocatalyst for oxygen evolution electrode of water-splitting

摘要

Water-splitting by using electric power produced by solar cells is promising system to produce hydrogen without fossil fuels. Oxygen evolving catalyst is, however, major problem to prevent using this system widely because precious materials are used in the catalyst. Considering from the photosynthesis II of plants, the compound of Ca-Mn-O is one of the candidates for the oxygen evolving catalyst. In this study, the synthesis condition and the oxygen evolving electrocatalytic activity of CaMn_2O_4·xH_2O are investigated. The overpotential at 0.1 mA/cm~2 was 0.28 V when using the electrode of carbon paste and CaMn_2O_4·H_2O with the weight ratio of 3:1.