Transition metal phosphides are perceived to be excellent electrocatalysts and have gradually become the primary candidates for highly efficient energy conversion devices. Coral-like Ni₂P-Ni₅P₄ polymorphs with observable heterointerfaces were synthesized via hydrothermal method followed by low-temperature phosphidation. The phase structures and the electronic interaction of the heterointerfaces have been identified by X-ray diffraction and X-ray photoelectron spectroscopy. The resulting Ni₂P-Ni₅P₄ catalyst exhibited a reasonable overpotential of 107 mV and a superior low overpotential of 238 mV at 10 mA cm⁻² for hydrogen evolution reaction and oxygen evolution reaction in 1 M KOH, respectively. In addition, excellent water-splitting performance of 10 mA cm⁻² at a low overpotential of 348 mV was obtained by combining the Ni₂P-Ni₅P₄/NF as both cathode and anode, which is lower than that of the Pt/C and RuO₂ catalyst couple. Such impressive performance might be ascribed to effective heterointerfaces of Ni₂P-Ni₅P₄ polymorphs.

过渡金属磷化物被认为是优良的电催化剂，并逐渐成为高效能量转换装置的主要候选者。珊瑚状Ni ₂ P-Ni ₅ P ₄多晶型具有可观察的异质界面是通过水热法和低温磷化合成的。异质界面的相结构和电子相互作用已通过 X 射线衍射和 X 射线光电子能谱确定。所得 Ni ₂ P-Ni ₅ P ₄催化剂在 10 mA cm ^-2下表现出 107 mV 的合理过电位和 238 mV 的超低过电位分别用于 1 M KOH 中的析氢反应和析氧反应。此外，通过将 Ni ₂ P-Ni ₅ P ₄ /NF 作为阴极和阳极组合，在 348 mV 的低过电位下获得了10 mA cm ^{-2 的}优异水分解性能，低于 Pt /C和RuO ₂催化剂对。这种令人印象深刻的性能可能归因于 Ni ₂ P-Ni ₅ P ₄多晶型物的有效异质界面。