Black Phosphorene with Removable Surface Protective Passivation via Covalent Functionalization and Chelation‐based Shield

Abstract 2D layered black phosphorus (BP), also known as phosphorene, has attracted significant attention for its potential applications in transistors, catalysis, biomedicine, energy conversion, and storage. However, addressing the reactivity of BP with oxygen and water, and thus achieving an effective passivation and deprotection of BP remains a key challenge. Here, we demonstrate a protective strategy based on covalent functionalization and chelation to passivate the BP surface. This approach involves the covalent modification of BP with tannic acid (TA) to reduce the reactivity of the lone electron pairs of BP, followed by the chelation of Fe ^III ions with TA to yield a protective shielding layer, thereby providing dual protection. This protection confers exceptional stability to BP, allowing it to remain stable for over five months under ambient conditions. Furthermore, BP can be deprotected by treatment with weak acids under ultrasonic conditions, thereby restoring its reactivity and utilizing it in broader fields.