Recent Advances in Black Phosphorus and Phosphorene Nanosheets: From Interface Engineering to Energy Storage, Catalysis, and Biomedicine

Black phosphorus (BP) and its few-layer counterpart, phosphorene, combine an anisotropic two-dimensional lattice, thickness-dependent electronic properties, strong near-infrared response, and chemically accessible phosphorus sites. The same surface chemistry that makes phosphorene attractive also makes it difficult to process and preserve reproducibly. This review focuses mainly on studies published from 2023 through September 2026 and examines how the field has shifted from proof-of-concept exfoliation toward deliberate interface control. Recent progress in liquid and electrochemical exfoliation, bipolar deposition, covalent functionalization, molecular passivation, and removable protective layers is discussed together with applications in Li- and Na-ion batteries, Li-S systems, supercapacitors, electrocatalytic water splitting, photocatalytic hydrogen evolution, CO2 reduction, drug delivery, phototherapy, tissue regeneration, antibacterial treatment, and biosafety. Across these areas, thickness, defect population, oxidation state, interfacial bonding, and nanosheet accessibility repeatedly determine both performance and failure. Particular attention is given to realistic electrochemical metrics, identification of catalytic active states, batch-to-batch reproducibility, and organ-specific safety. The review closes by outlining practical requirements for moving phosphorene from optimized laboratory demonstrations toward reproducible energy, catalytic, and biomedical technologies.