Uniquely confining Cu 2 S nanoparticles in graphitized carbon fibers for enhanced oxygen evolution reaction.

Up to now, the literature on Cu2 S with specific morphology applied to oxygen evolution reaction (OER) in the electrocatalytic field has been limited. In this work, unique peapod-like Cu2 S/C exhibiting superb electrocatalytic performance toward OER is successfully synthesized, by employing Cu(OH)2 nanorods as the template and nontoxic glucose as the carbon source and then annealing with sublimed sulfur. It can be seen that this work explores a new application area for Cu2 S. More precisely, the novel morphology contributes to increasing the electrochemical active surface area effectively and promoting contact between the Cu2 S nanoparticles and the electrolyte. During electrochemical measurements, the peapod-like Cu2 S/C shows enhanced electrocatalytic activity with a low overpotential of 401 mV at the current density of 10 mA cm-2 and a Tafel slope of 52 mV dec-1 . More importantly, our material is able to maintain stability for at least 8 h at constant potential and the current loss is negligible after 2000 cycles. Obviously, these striking properties fully demonstrate that the peapod-like Cu2 S/C as an efficient catalyst shows great promise for OER.