Electrocatalysts with low overpotential and high stability are highly demanded in water-splitting system. The efficiency of water-splitting is largely restricted by the oxygen evolution reaction (OER). Here, we developed a two-step method to prepare 3D porous material through chemical vapor deposition and electrodeposition combined with the first-principles calculations. Ultrathin α-Co(OH)₂ nanosheets grown on the combined substrate of N-doped carbon nanotubes (NCNTs) and nickel foam were fabricated to investigate their electrochemical behaviour. Because of the characteristics of the ultrathin, microporous α-Co(OH)₂ and its derivatives, the 3D Co(OH)₂@[email protected] exhibits outstanding performance as a bifunctional catalyst for water-splitting. The overpotentials to achieve 10 mA cm⁻² current density in 1 M KOH for OER and hydrogen evolution reaction (HER) are 270 mV and 170 mV, respectively. The as-prepared material exhibits superior stability, which generate 10 mA cm⁻² current density in overall water-splitting over 600 h without obvious degradation in 1 M KOH at voltage of 1.72 V vs. RHE. The first-principles calculations reveal that the N-doping not only can effectively enhance the interaction between the substrate and active material (CoOOH), but also modulate the electronic structure of CoOOH to speed up the O₂ releasing during the OER.

在水分解系统中，对低电势和高稳定性的电催化剂有很高的要求。氧气分解反应（OER）在很大程度上限制了水分解的效率。在这里，我们开发了一种通过两步法通过化学气相沉积和电沉积结合第一原理计算来制备3D多孔材料的方法。制备了在N掺杂碳纳米管（NCNT）和泡沫镍的复合基材上生长的超薄α-Co（OH）₂纳米片，以研究其电化学行为。由于超薄微孔α-Co（OH）₂及其衍生物的特性，因此3D Co（OH）₂@ [电子邮件保护]作为水分解用双功能催化剂表现出出色的性能。对于OER和析氢反应（HER），在1 M KOH中达到10 mA cm ^-2电流密度的过电位分别为270 mV和170 mV。所制备的材料表现出优异的稳定性，在相对于RHE的电压为1.72 V的情况下，在600 h的总水分解中产生10 mA cm ^-2的电流密度，而在1 M KOH中没有明显降解。第一性原理计算表明，N掺杂不仅可以有效增强底物与活性材料（CoOOH）之间的相互作用，而且可以调节CoOOH的电子结构，从而加快OER释放过程中O _2的释放。