Co(II) dissolved in acetate buffer at pH 7 is found to be a good water oxidation catalyst (WOC) showing electrocatalytic water oxidation current significantly greater than Co(II) in phosphate buffer under the same conditions owing to the higher solubility of the former. When electrodeposited on ITO/FTO electrodes it forms acetate bound cobalt(II)oxide based material (Co-Ac-WOC) showing catalytic water oxidation current density of 0.1 mA/cm$^{2}$ at 830 mV and 1 mA/cm$^{2}$ at 1 V in a pH 7 buffer solution. The morphology of Co-Ac-OEC is investigated with AFM, HR-TEM and SEM (at different times and electrodeposition potentials). The chemical composition of Co-Ac-OEC is investigated using XPS, EDX, combustion analysis and ATR-FTIR which indicates that this material has a CoO core with chloride and acetate anions bound to the Co center. Sodium is found to be integrated in the Co-Ac-WOC. The presence of the sodium ions and the chloride ions lowers the onset potential for oxygen evolution reaction (OER) by 240 mV relative to the classic Co-Pi at pH 7. The lower onset potential and higher OER current lowers the exchange current density to 10$^{-6.7}$ in Co-Ac-WOC relative to 10$^{-8}$-10$^{-10}$ in Co-Pi and its derivatives.
翻译:在pH 7 PH 7 的乙酸缓冲中溶解的碳(II)溶解于乙酸缓冲中,被认为是一种良好的水氧化催化剂(WOC),在PH 7缓冲溶性较高的情况下,磷酸盐缓冲中的电催化水氧化值明显高于Co(II),在ITO/FTO电极中,当电沉降在ITO/FTO电极中时,它形成乙酸结合钴(II)基料(Co-Ac-WOC)的化学成分时,使用XPS、EDX、燃烧分析以及ATR-TFIR,这表明该物质在碳核心中含氯化物,浓度高于1 mA/cm2美元,在pH 7 缓冲溶液溶液溶液溶液溶液溶液中,CO-Ac-TEM和SEM(在不同时间和电降解潜能值不同)的形态学研究。