Rapid Activation of Platinum with Black Phosphorus for Efficient Hydrogen Evolution.

Modulation of the electronic structure of metal catalysts is an effective approach to optimize the electrocatalytic activity. Herein, we show a surprisingly strong activation effect of black phosphorus (BP) on platinum (Pt) catalysts to give greatly enhanced catalytic activity in the hydrogen evolution reaction (HER). The unique and negative binding energy between BP and Pt leads to spontaneous formation of Pt-P bonds producing strong synergistic ligand effects on the Pt nanoparticles. No Pt-P bonds are formed with red phosphorus which is another allotrope of P. By controlling the number of Pt-P bonds, 3.5-fold enhancement in the HER activity can be achieved from the BP-activated Pt catalyst and the activity is 6.1 times higher than that of the state-of-the-art commercial Pt/C catalyst. The BP-activated Pt catalyst exhibits a current density of 82.89 mA cm-2 with only 1 μg of Pt in 1 m KOH at an overpotential of 70 mV.