Porous heterostructure of graphene/hexagonal boron nitride as an efficient electrocatalyst for hydrogen peroxide generation

Abstract

AbstractCompared with the traditional heteroatom doping, employing heterostructure is a new modulating approach for carbon‐based electrocatalysts. Herein, a facile ball milling‐assisted route is proposed to synthesize porous carbon materials composed of abundant graphene/hexagonal boron nitride (G/h‐BN) heterostructures. Metal Ni powder and nanoscale h‐BN sheets are used as a catalytic substrate/hard template and “nucleation seed” for the formation of the heterostructure, respectively. As‐prepared G/h‐BN heterostructures exhibit enhanced electrocatalytic activity toward H2O2 generation with 86%–95% selectivity at the range of 0.45–0.75 V versus reversible hydrogen electrode (RHE) and a positive onset potential of 0.79 versus RHE (defined at a ring current density of 0.3 mA cm−2) in the alkaline solution. In a flow cell, G/h‐BN heterostructured electrocatalyst has a H2O2 production rate of up to 762 mmol gcatalyst−1 h−1 and Faradaic efficiency of over 75% during 12 h testing, superior to the reported carbon‐based electrocatalysts. The density functional theory simulation suggests that the B atoms at the interface of the G/h‐BN heterostructure are the key active sites. This research provides a new route to activate carbon catalysts toward highly active and selective O2‐to‐H2O2 conversion.