概论世界上的一切事物都有两个方面。我们应该正确认识它的两个方面，追求积极的一面，排除消极的一面。近年来，二维（2D）黑磷（BP）受到了极大的关注，并因其固有的性质（例如厚度依赖的带隙、高迁移率、高度各向异性电荷传输以及优异的生物降解性和生物相容性。一方面，二维BP在环境条件下的快速降解成为一个重要的瓶颈，很大程度上阻碍了其在光学、光电器件和光催化中的实际应用。另一方面，正是由于其环境不稳定性，2D BP作为一种新型的癌症药物输送系统纳米药物，不仅可以满足有效的癌症治疗，而且可以使其在体内安全地生物降解。到目前为止，各种表面功能类型和方法已被用来合理修改 2D BP 以满足先进纳米光子学日益增长的需求。在本篇中，我们以两种相反的方式描述了我们对 2D BP 表面工程的研究：（i）通过各种方法稳定2D BP，以获得具有显着光响应行为和环境结构稳定性的先进纳米光子器件，以及（ii）充分利用2D BP的生物降解性、生物相容性和生物活性（例如光热疗法、光动力疗法和生物成像）为生物光子应用构建高性能传输纳米平台。我们强调表面工程 2D BP 通过杂原子掺入、聚合物功能化、涂层、异质结构等各种表面功能实现先进纳米光子学的目标，包括光子器件（光学、光电子学和光催化）和光诱导癌症治疗从潜在应用的角度，简要讨论了表面工程二维BP的基本性质以及基于表面工程二维BP的纳米光子器件的最新进展。对于光子器件，表面工程2D BP不仅可以有效提高环境结构稳定性，同时还能保持光响应性能，使基于2D BP的器件能够获得广泛的实际应用。在光诱导癌症治疗方面，表面工程2D BP由于其毒性可忽略不计且具有优异的生物降解性和生物相容性，更适合癌症的治疗。我们还对这个重要且快速发展的领域的未来机遇和挑战提出了我们的看法。预计该帐户可以吸引该领域的更多关注，并激励各个研究团体的更多科学家加速 2D BP 的开发，以实现更广泛的高性能纳米光子应用。

ConspectusEverything in the world has two sides. We should correctly understand its two sides to pursue the positive side and get rid of the negative side. Recently, two-dimensional (2D) black phosphorus (BP) has received a tremendous amount of attention and has been applied for broad applications in optoelectronics, transistors, logic devices, and biomedicines due to its intrinsic properties, e.g., thickness-dependent bandgap, high mobility, highly anisotropic charge transport, and excellent biodegradability and biocompatibility. On one hand, rapid degradation of 2D BP under ambient conditions becomes a vital bottleneck that largely hampers its practical applications in optical and optoelectronic devices and photocatalysis. On the other hand, just because of its ambient instability, 2D BP as a novel kind of nanomedicine in a cancer drug delivery system can not only satisfy effective cancer therapy but also enable its safe biodegradation in vivo. Until now, a variety of surface functionality types and approaches have been employed to rationally modify 2D BP to meet the growing requirements of advanced nanophotonics.In this Account, we describe our research on surface engineering of 2D BP in two opposite ways: (i) stabilizing 2D BP by various approaches for advanced nanophotonic devices with both remarkable photoresponse behavior and environmentally structural stability and (ii) making full use of biodegradation, biocompatibility, and biological activity (e.g., photothermal therapy, photodynamic therapy, and bioimaging) of 2D BP for the construction of high-performance delivery nanoplatforms for biophotonic applications. We highlight the targeted aims of the surface-engineered 2D BP for advanced nanophotonics, including photonic devices (optics, optoelectronics, and photocatalysis) and photoinduced cancer therapy, by means of various surface functionalities, such as heteroatom incorporation, polymer functionalization, coating, heterostructure design, etc. From the viewpoint of potential applications, the fundamental properties of surface-engineered 2D BP and recent advances in surface-engineered 2D BP-based nanophotonic devices are briefly discussed. For the photonic devices, surface-engineered 2D BP can not only effectively improve environmentally structural stability but also simultaneously maintain photoresponse performance, enabling 2D BP-based devices for a wide range of practical applications. In terms of the photoinduced cancer therapy, surface-engineered 2D BP is more appropriate for the treatment of cancer due to negligible toxicity and excellent biodegradation and biocompatibility. We also provide our perspectives on future opportunities and challenges in this important and fast-growing field. It is envisioned that this Account can attract more attention in this area and inspire more scientists in a variety of research communities to accelerate the development of 2D BP for more widespread high-performance nanophotonic applications.