Rational design of TiO2–V2O5–C nanostructure grafted by N-doped graphene with enhanced photocatalysis and lithium ion store performances

Abstract

Highly ordered mesoporous crystalline C–TiO₂–V₂O₅ core–shell microspheres encapsulated by porous carbon further embedded in N-doped graphene network (GN–TV–C) nanostructures were fabricated by a simple combination of hydrothermal-calculation method. Such material exhibits a highly efficient photocatalytic activity for water splitting, as well as a high specific capacity and exceptional cycle ability in LIBs. The extrusive features of such material include the assembly of components in a manner that enables an effective integration between the constituents and the ability to modify the electronic properties of GN–TV–C. The positive synergistic incorporation between TiO₂ and V₂O₅, the high electrical conductivity, and the three-dimensional hierarchically mesoporous nanostructure of these composites result into a highly active photocatalytic ability, showing patterns of increased light harvesting ability and promoted exciton dissociation, and excellent electrochemical performance in terms of a high rate capability and stable cycling. Profiting from the dual insurance of the flexible carbon layer derived from glucose and elastic GN walls with superior specific surface areas, a significant enhancement in the electron transfer and electronic diffusion channels, and a highly enhanced structural stability of the TiO₂-based electrode material were simultaneously obtained. In addition, the synergistic function among TiO₂, V₂O₅ and GN involving the optimized energy gap, the compromised particle assembly and surface defects, as well as their distinctive core–shell nanostructures were extensively studied. The carbon shell serves as a blocking layer that retards the interfacial recombination during photocatalysis, thereby protecting the active materials from pulverization during the superior cycles in the energy store. The current study may provide us an alternative approach for improving the performances of TiO₂ nanocrystals used in energy storage and photocatalysis applications.