Black phosphorus (BP),a promising two-dimensional layer material,has attracted increasing attention due to its high carrier mobility,thickness-dependent tunable bandgap,in-plane anisotropy,and other advantageous characteristics.Because of these excellent characteristics,BP has been considered for applications in optics,electronics,optoelectronics,sensors,and energy storage.However,early studies found that BP has high chemical activity due to the lone pair electrons of P atoms on the surface and edges,resulting in rapid degradation under ambient conditions and limiting many applications.Recently,these thorny issues have been alleviated through superior physical and chemical passivation techniques,and passivated BP can be used in various devices under ambient and water conditions with excellent performance over a long period.This review,highlights the critical problems addressed in solving the serious instability of BP in a harsh environment by effective passivation technology.These unique strategies can provide more researchers with a fundamental study of the fascinating properties of BP.Finally,we found that passivated BP not only showed good stability under ambient conditions but also exhibited excellent performance compared with the original BP.Therefore,it is anticipated that this overview can contribute to the application of BP.