The synthesis of black phosphorus: from zero- to three-dimensional nanostructures

The discovery of monolayered black phosphorus (phosphorene) in 2014 gives rise to enormous research enthusiasm for its unique electrical and physicochemical properties. Since then, the applications of black phosphorus and its nanostructures have been extended to various fields covering field effect transistors, rechargeable batteries, electrocatalysis, sensors, thermoelectric materials, and so forth. However, controllable and scalable synthesis of BP and its nanostructures remains a challenge. In this review, we provide a state-of-the-art overview of the progress towards the synthesis of bulk BP and its typical nanostructured counterparts, including the 0D BP (quantum dots), 1D BP (nano/micro-belts), 2D BP (phosphorene), and 3D BP (sponges). Special focus will be made on the various synthetic methods, the characterizations of products, and the corresponding necessary improvements. We close the review with a look at the challenges and perspectives regarding future studies.