Creating vacancy is often highly effective in enhancing the hydrogen evolution performance of transition metal-based catalysts. Vacancy-rich Ni nanosheets have been fabricated via topochemical formation of two-dimentional (2D) Ni₂B on graphene precursor followed by boron leaching. Anchored on graphene, a few atomic layered Ni₂B nanosheets are first obtained by reduction and annealing. Large number of atomic vacancies are then generated in the Ni₂B layer via leaching boron atoms. When used for hydrogen evolution reaction (HER), the vacancy-rich Ni/Ni(OH)₂ heterostructure nanosheets demonstrate remarkable performance with a low overpotential of 159 mV at a current density of 10 mA·cm⁻² in alkaline solution, a dramatic improvement over 262 mV of its precursor. This enhancement is associated with the formation of vacancies which introduce more active sites for HER along Ni/Ni(OH)₂ heterointerfaces. This work offers a facile and universal route to introduce vacancies and improve catalytic activity.

产生空位通常对提高过渡金属基催化剂的析氢性能非常有效。通过在石墨烯前体上形成二维 (2D) Ni ₂ B 的拓扑化学形成，然后进行硼浸出，已经制备出富含空位的 Ni 纳米片。锚定在石墨烯上，首先通过还原和退火获得一些原子层状Ni ₂ B 纳米片。然后通过浸出硼原子在Ni ₂ B 层中产生大量原子空位。当用于析氢反应（HER）时，富含空位的 Ni/Ni(OH) ₂异质结构纳米片表现出卓越的性能，在 10 mA·cm ^-2的电流密度下具有 159 mV 的低过电位在碱性溶液中，其前体的 262 mV 有显着改善。这种增强与空位的形成有关，空位为沿 Ni/Ni(OH) ₂异质界面的HER 引入了更多的活性位点。这项工作为引入空位和提高催化活性提供了一种简便而通用的途径。