Preparation of TiO2 nanofibers, porous nanotubes, RGO/TiO2 composite by electrospinning and hydrothermal synthesis and their applications in improving the electrochemical hydrogen storage properties of Co2B material

Abstract

Co2B hydrogen storage material was prepared via a high temperature solid phase process. The TiO2 nanofibers (TiO2–NF) and TiO2 porous nanotubes (TiO2-NT) with different size, structure and morphology were fabricated by electrospinning and hydrothermal synthesis. In order to improve the conductivity, the reduced graphene oxide/TiO2 nanotubes composite (RGO/TiO2-NT) was synthesized by an alkaline hydrothermal process. The three-dimensional porous TiO2 nanotubes were attached to the two-dimensional RGO and formed a uniform dispersion. For the purpose of improving the electrochemical performance of Co2B, composites of Co2B doped with TiO2–NF, TiO2-NT and RGO/TiO2-NT were manufactured by ball milling. Ultimately, all the composite electrodes showed higher discharge capacities than ordinary Co2B. Among them, Co2B modified with RGO/TiO2-NT exhibited the highest discharge capacity (691.4 mAh/g). TiO2-NT with large specific surface area and unique tubular porous structure can offer sufficient electrochemical active sites to anchor hydrogen and improve the electrocatalytic activity of Co2B, meanwhile, the RGO component in RGO/TiO2-NT with excellent electrical conduction can further provide fast channels for charger transfer during the charging/discharging processes. Moreover, the corrosion resistance, HRD and kinetics performance of Co2B were also enhanced after doping of TiO2–NF, TiO2-NT and RGO/TiO2-NT.