The electrochemical water splitting in alkaline media is troubled by the lack of efficient electrocatalysts for hydrogen evolution reaction (HER). Herein, a crystalline/amorphous CoP/MnO_x heterostructure is converted from a single-phase bimetallic Co–Mn oxide by phase separation strategy. The CoP/MnO_x heterostructure only requires an overpotential of 135 mV to reach 10 mA cm⁻² in 1 M KOH, which is lower than that of CoP (184 mV). The interface effect between CoP and MnO_x is beneficial to the improvement of HER activity, which is confirmed by means of selective etching of MnO_x and infrared spectroscopy. Moreover, the crystal size of CoP phase in the heterostructure is lower than that of the mono-component CoP. Furthermore, the decrease of precursor crystal size will give rise to a decrease in the CoP crystal size of heterostructure. The decline of crystal size results in higher active surface area and greater number of interfaces.

碱性介质中的电化学水分解因缺乏用于析氢反应 (HER) 的高效电催化剂而受到困扰。在此，通过相分离策略从单相双金属 Co-Mn 氧化物转化为结晶/非晶 CoP/MnO _{x异质结构。}CoP/MnO _x异质结构仅需要 135 mV 的过电位即可在 1 M KOH 中达到 10 mA cm ^-2，低于 CoP (184 mV)。CoP和MnO _x之间的界面效应有利于HER活性的提高，这一点通过MnO _{x的选择性刻蚀得到证实}和红外光谱。此外，异质结构中 CoP 相的晶体尺寸低于单组分 CoP。此外，前体晶体尺寸的减小将导致异质结构的CoP晶体尺寸减小。晶体尺寸的下降导致更高的活性表面积和更多的界面。