Dual template-induced construction of three-dimensional porous SiO_(2)/NC/Co-CNTs heterostructure with highly dispersed active sites for efficient oxygen evolution reaction

The development and exploration of efficient and economical electrocatalysts for oxygen evolution reaction(OER)represents the main bottleneck to unlocking a sustainable energy scenario based on elec trocataly tic water splitting.Nano scale integration of three-dimensional(3D)porous heterostructure with highly dispersed active sites and good structural stability is challenging.Herein,a dual template route is developed to construct the 3D porous SiO_(2)/nitrogen-doped carbon(NC)/Co-carbon nano tubes(CNTs)hetero structure.Importantly,the hard template(SiO_(2) nano spheres)contributes to 3D porous structure,increases the specific surface area,and promotes the contact area of the electrolyte.At the same time,the soft template(basic zinc carbonate)can control the growth of 1D CNTs and facilitate the exposure of the active sites.Apparently,3D porous SiO_(2)/NC/Co-CNTs hetero structure inherits highly dispersed Co nanoparticles coated by NC.CNTs conductive channels and abundant N hetero atoms doping are reasonably constructed by a dual template strategy.Therefore,SiO_(2)/NC/Co-CNTs catalyst provides an extraordinary activity for the OER in alkaline media,with a low overpotential of 298 mV at a current density of 10 mA·cm^(-2).Furthermore,SiO_(2)/NC/Co-CNTs hetero structure enables excellent long-term durability with a 10 mV decay in overpotential after 3000 cyclic voltammetry cycles,and 97%remain in current density over 20 h.It is believed that this dual template strategy can provide a new and simple way to construct a highly dispersed active site in electrocatalysts.