Tuning 2D Black Phosphorus: Defect Tailoring and Surface Functionalization

Within a decade, black phosphorus has become an important 2D material for sustainable energy areas and bioapplications due to its great electronic properties and biocompatibility. Pristine black phosphorus suffers from intrinsic shortages like rapid degradation and poor solubility, which require physical and chemical tuning methods. There also lacks an effective approach to synthesize single-crystal black phosphorus with large areas. This review article provides a forward-looking overview of significance, mechanism studies, status quo, and outlooks of defect-tailoring and surface functionalization in black phosphorus; the prior focuses on the lattice while the latter focuses on the surface. Particularly, both approaches can alter chemical and electronic properties such as air stability, solubility, carrier mobility, and band gap. Functionalization further enables the BP surface to immobilize various biomarkers and medical molecules, which largely boost its future applications in biosensors and theranotics. Finally, we discuss some unresolved issues and future applications, especially in tuning BP especially in BP synthesis, atomic modification methods, and bioapplications.