Room Temperature Preparation of Two-Dimensional Black Phosphorus@Metal Organic Framework Heterojunctions and Their Efficient Overall Water-Splitting Electrocatalytic Reactions

Black phosphorus/two-dimensional (2D) metal-organic framework (BP@MOF) heterojunctions were synthesized via templated growth of 2D MOF-Fe/Co nanoplatelets on the surface of exfoliated BP nanosheets at room temperature. Because Fe³⁺ and Co²⁺ ions were absorbed onto the BP surface through coordination with the lone pair electrons of 2D BP, the BP@MOF heterojunction had an intimate interface with strong interactions. Electrochemical oxygen and hydrogen evolution reactions were studied using BP@MOF as the electrocatalyst. High activity of the overall water splitting in 1.0 M KOH was observed under a current density of 10 mA cm^-2. The corresponding overpotentials for HER and OER were as low as 180 and 246 mV, respectively. Meanwhile, the BP@MOF exhibited good environmental stability and long-term electrocatalytic activity for OER and HER, owing to the encapsulation of BP nanosheets by the 2D MOF-Fe/Co. Through this study, a unique hybrid 2D nanomaterial is discovered for the efficient electrolytic splitting of water.