Synthesis of two-dimensional (2D) materials that is readily scalable, cost-effective, and eco-friendly is important from both scientific and industrial viewpoints. Currently, these 2D materials are synthesized either by selective etching of relatively expensive layered solids, viz. using a top-down approach, or by autoclaving metal salts/organic compounds. Herein, we describe a near-ambient, one-pot, inexpensive, scalable pathway to convert—through a bottom-up approach—5 different water-insoluble Mn-bearing precursors, viz. Mn₃O₄, Mn₂O₃, MnB, Mn₅SiB₂, and Mn₂AlB₂, into birnessite-based 2D flakes that, in some cases, are remarkably crystalline. The precursor powders are immersed in 25 wt % tetramethylammonium hydroxide aqueous solutions at 50°C to 80°C for 2 to 4 days. The structures, compositions, oxidation states, and morphologies of the synthesized flakes are determined using a battery of characterization techniques. The synthesized 2D sheets demonstrate reversible O₂ electrocatalysis with activities comparable with those of a commercial Pt/C catalyst.

从科学和工业的角度来看，合成易于扩展、具有成本效益和环保的二维 (2D) 材料非常重要。目前，这些二维材料是通过选择性蚀刻相对昂贵的层状固体来合成的，即。使用自上而下的方法，或通过高压灭菌金属盐/有机化合物。在这里，我们描述了一种近乎环境、一锅法、廉价、可扩展的途径，通过自下而上的方法转化 5 种不同的水不溶性含锰前体，即。Mn ₃ O ₄、Mn ₂ O ₃、MnB、Mn ₅ SiB ₂和Mn ₂ AlB ₂，变成基于水钠锰矿的二维薄片，在某些情况下，这些薄片非常结晶。将前体粉末在 50°C 至 80°C 下浸入 25 wt% 四甲基氢氧化铵水溶液中 2 至 4 天。使用一系列表征技术确定合成薄片的结构、组成、氧化态和形态。合成的二维片材表现出可逆的 O ₂电催化活性，其活性与商业 Pt/C 催化剂的活性相当。