In this report, a Cr regulated ternary CoFeCr hydroxide microsphere composite for enhanced water oxidation was fabricated using a facile electrodeposition method. The incorporation of Cr affects the oxidation state of Co and compared to the binary cobalt-iron hydroxide composite, the ternary composite shows excellent electrocatalytic performance for oxygen evolution reaction (OER) in alkaline media, whose onset potential is only around 1.43 V vs reversible hydrogen electrode (RHE) and the overpotential is merely of 270 mV to achieve a current density of 100 mA cm⁻² in 1 M KOH. This enhanced oxygen evolution activity is attributed to the “regulation effect” of chromium. In other words, during water oxidation, chromium in the composite is partially oxidized into high valence 6 + and the electrons generated by this oxidation reaction can be transferred to the cobalt cites to maintain cobalt at a relatively lower oxidation valence state (but OER active), which accelerates the third electron-transfer process (M-O + OH⁻ → M-OOH + e⁻).

在此报告中，使用简便的电沉积方法制备了用于增强水氧化作用的Cr调节的三元CoFeCr氢氧化物微球复合材料。Cr的掺入会影响Co的氧化态，与二元钴铁氢氧化物复合物相比，三元复合物在碱性介质中对氧放出反应（OER）表现出优异的电催化性能，其起始电势相对于可逆氢仅为1.43 V左右电极（RHE）且过电势仅为270 mV，以实现100 mA cm ^-2的电流密度在1 M KOH中。增强的析氧活性归因于铬的“调节作用”。换句话说，在水氧化过程中，复合材料中的铬被部分氧化成高价6 +，并且该氧化反应产生的电子可以转移到钴中，从而使钴保持在相对较低的氧化价状态（但OER具有活性） ，这加速了第三电子转移过程（MO + OH ^- →M-OOH + E ^- ）。