Here we present a novel combined-strategy of cation tuning and surface engineering for the fabrication of highly active, earth-abundant, and robust two-dimensional Ni₂P electrocatalyst. The nanosheets have lateral sizes of few hundred nm with thicknesses of ~6 nm. Our theoretical calculations suggest the effectiveness of vanadium doping and oxygen plasma, which do not only enhance the density-of-state at Fermi level, but also make the Ni sites more susceptible to OH⁻ adsorption. The oxygen plasma treatment can increase the wettability of the catalyst toward KOH solution, improving the contact angle from 44.95° to 16.8°, and also induce a higher BET surface area; hence, more active sites and lower charge transfer resistance are obtained. As a result, the catalyst requires small overpotentials of 257 and 108 mV to drive ±10 mA cm⁻² alongside with modest Tafel slope of 43.5 and 72.3 mV dec⁻¹ for oxygen evolution reaction and hydrogen evolution reaction in 1.0 M KOH solution, respectively. When employed for overall water splitting, the catalyst demonstrates a low voltage of 1.56 V to achieve 10 mA cm⁻² with good stability and durability, outperforming the state-of-the-art IrO₂ || Pt/C which needs 1.69 V. This work opens a new approach to engineer low-cost monometallic phosphides for highly efficient water splitting.

在这里，我们提出了一种阳离子调节和表面工程的新型组合策略，用于制造高活性，富含地球的，坚固的二维Ni ₂ P电催化剂。纳米片的横向尺寸为几百纳米，厚度为〜6纳米。我们的理论计算表明钒掺杂和氧等离子体的有效性，这不仅增强在费米能级密度的状态，同时也使镍网站OH更容易^-吸附。氧等离子处理可以提高催化剂对KOH溶液的润湿性，将接触角从44.95°改善到16.8°，还可以诱导更大的BET表面积；因此，获得了更多的活性位点和更低的电荷转移电阻。结果，该催化剂需要较小的257和108 mV的超电势来驱动±10 mA cm ^-2，同时在1.0 M KOH溶液中用于氧气析出反应和氢气析出反应的Tafel斜率分别为43.5和72.3 mV dec ^-1。 。当用于整体水分解时，该催化剂表现出1.56 V的低电压，可实现10 mA cm ^-2的稳定性和耐久性，优于最新的IrO ₂|| 需要1.69 V的Pt / C。这项工作为工程设计低成本单金属磷化物提供了一种新方法，以实现高效的水分解。