Fabrication of ultrathin 2D nonlayered nanomaterials remains challenging, yet significant due to the new promises in electrochemical functionalities. However, current strategies are largely restricted to intrinsically layered materials. Herein, a combinatorial self‐regulating acid etching and topotactic transformation strategy is developed to unprecedentedly prepare vertically stacked ultrathin 2D nonlayered nickel selenide nanosheets. Due to the inhibited hydrolyzation under acidic conditions, the self‐regulating acid etching results in ultrathin layered nickel hydroxides (two layers). The ultrathin structure allows limited epitaxial extension during selenization, i.e., the nondestructive topotactic transformation, enabling facile artificial engineering of hydroxide foundation frameworks into ultrathin nonlayered selenides. Consequently, the exquisite nonlayered nickel selenide affords high turnover frequencies, electrochemical surface areas, exchange current densities, and low Tafel slopes, as well as facilitating charge transfer toward both oxygen and hydrogen evolution reactions. Thus, the kinetically favorable bifunctional electrocatalyst delivers advanced and robust overall water splitting activities in alkaline intermediates. The integrated methodology may open up a new pathway for designing other highly active 2D nonlayered electrocatalysts.

中文翻译：

---

用于全水电解的超薄二维非层状硒化镍的透平工程

超薄二维非层状纳米材料的制造仍然具有挑战性，但由于电化学功能方面的新希望，因此意义重大。但是，当前的策略在很大程度上限于本质上分层的材料。在本文中，开发了一种组合的自调节酸蚀刻和全能转化策略，以前所未有的方式制备垂直堆叠的超薄二维非层硒化镍纳米片。由于在酸性条件下水解受到抑制，因此自调节式酸蚀会产生超薄层状氢氧化镍（两层）。超薄结构在硒化过程中允许有限的外延延伸，即无破坏性的全能转变，从而可以将氢氧化物基础骨架轻松地人工工程化为超薄的非层状硒化物。所以，精致的非层状硒化镍具有高周转频率，电化学表面积，交换电流密度和低Tafel斜率，并有利于电荷向氧气和氢气的释放反应转移。因此，动力学上有利的双功能电催化剂在碱性中间体中提供了先进而稳定的总水分解活性。集成方法可以为设计其他高活性二维非层状电催化剂开辟一条新途径。动力学上有利的双功能电催化剂在碱性中间体中提供了先进而稳定的整体水分解活性。集成方法可以为设计其他高活性二维非层状电催化剂开辟一条新途径。动力学上有利的双功能电催化剂在碱性中间体中提供了先进而稳定的整体水分解活性。集成方法可以为设计其他高活性二维非层状电催化剂开辟一条新途径。