Rh metallene with functionalized polypyrrole surface for hydrogen evolution over a wide pH range.

Interface engineering of two-dimensional (2D) materials by conductive polymer modification is one of the valid methods to promote hydrogen evolution reaction (HER) performance. Herein, we report a simple and universal strategy for the synthesis of polypyrrole (PPy) modified Rh metallene (Rh@PPy metallene) towards an efficient pH-universal HER. Due to the unique ultrathin 2D metallene structure and the optimized electronic structure between the metallene-PPy surfaces, the as-prepared Rh@PPy metallene not only exhibits excellent HER activity with low overpotentials of 16, 39 and 42 mV in 0.5 M H 2 SO 4 , 1 M KOH, and 1 M phosphate buffer solution at current density of 10 mA cm -2 , but also displays outstanding stability and durability. This work provides a well-founded pathway to constructe metallene-organic interfaces for various electrocatalytic applications.