Uniquely confining Cu₂S nanoparticles in graphitized carbon fibers for enhanced oxygen evolution reaction

Up to now, the literature on Cu₂S with specific morphology applied to oxygen evolution reaction (OER) in the electrocatalytic field has been limited. In this work, unique peapod-like Cu₂S/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 Cu₂S. More precisely, the novel morphology contributes to increasing the electrochemical active surface area effectively and promoting contact between the Cu₂S nanoparticles and the electrolyte. During electrochemical measurements, the peapod-like Cu₂S/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 Cu₂S/C as an efficient catalyst shows great promise for OER.