Hollow molybdenum oxide-graphene oxide spheres as a binder-free electrocatalyst membrane with enhanced hydrogen evolution efficiency

Abstract To make electrochemical water splitting to produce hydrogen realistic, earth-abundant and low-cost electrocatalysts need to be developed. In this work, we demonstrate a facile strategy to synthesize decorated molybdenum oxide (MoO2) nanoparticles on graphene oxide (GO) layers. With GO sheets, hollow spheres of MoO2-G are formed. Incorporation of the MoO2-G balls into a cryogel, subsequent freeze-drying and carbonization, gives a conducting MoO2-G macroporous membrane. The hybrid membrane exhibits excellent performance for HER with a Tafel slope of 52 mV dec-1 at an onset potential of −100 mV and high stability, reflected in the stable cathodic current over 23 h. of operation.