Few-layer black phosphorus (BP) nanosheets were first reported as a 2D material for the application of field-effect transistors in 2014 and have stimulated intense activity among physicists, chemists, and material and biomedical scientists, driving research into novel synthetic techniques to produce BP nanosheets. At present, exfoliation is the main route toward few-layer BP nanosheets via employing bulk BP as raw material. However, this is a complicated and time-consuming process, which is difficult for the large-scale synthesis of BP nanosheets. Moreover, BP degrades rapidly when exfoliated to nanoscale dimensions, resulting in the rapid loss of semiconducting properties. Here, we report the direct wet-chemical synthesis of few-layer BP nanosheets in gram-scale quantities in a bottom-up approach based on common laboratory reagents at low temperature, showing excellent stability due to partial oxidation of surface. Solvent and temperature are two critical factors, controlling not only the formation of BP nanosheets but also the thickness. The as-prepared BP nanosheets can extract hydrogen from pure water (pH = 6.8), exhibiting more than 24-fold higher activity than the well-known C₃N₄ nanosheets. Our results reporting the ability to prepare few-layer BP nanosheets with a facile, scalable, low-cost approach take us a step closer to real-world applications of phosphorene including next-generation metal-free photocatalysts for photosynthesis.

几层黑磷（BP）纳米片在2014年首次被报道为2D材料用于场效应晶体管的应用，并激起了物理学家，化学家以及材料和生物医学科学家的强烈活动，推动了对合成新技术的研究， BP纳米片。目前，剥脱是通过使用块状BP作为原料而朝向几层BP纳米片的主要途径。但是，这是一个复杂且耗时的过程，对于大规模合成BP纳米片而言是困难的。此外，当剥离到纳米级尺寸时，BP会迅速降解，从而导致半导体性能的快速丧失。这里，我们在低温下基于常规实验室试剂，以自下而上的方法报告了克级量的几层BP纳米片的直接湿化学合成，由于表面的部分氧化，显示出极好的稳定性。溶剂和温度是两个关键因素，不仅控制BP纳米片的形成，而且控制厚度。所制备的BP纳米片可以从纯水（pH = 6.8）中提取氢，其活性比众所周知的C高24倍以上。₃ N ₄纳米片。我们的研究结果表明，采用一种简便，可扩展，低成本的方法能够制备几层BP纳米片的能力使我们更接近磷光体的实际应用，包括用于光合作用的下一代无金属光催化剂。