Nanoparticle intercalation-modulated stretchable conductive graphene fibers with combined photoelectric properties

Abstract

Graphene fiber with superb properties poses an important role in future functional fibers and devices. However, the fibers made of neat graphene sheets remain brittle and the electrical conductivity of graphene/polymer fibers is very poor, which all together hiders wide use of graphene fibers. It remains a big challenge to obtain functional graphene fibers with combined electrical and mechanical properties. Here, we demonstrate a simple wet spinning of stretchable conductive graphene fibers through uniform intercalation of TiO2 nanoparticles between graphene sheets. The TiO2 nanoparticles induce formation of numerous winkles on graphene sheets which all together makes the composite fibers show combined superb mechanical, electrical and photoelectric performances. With increasing of TiO2 from 0 to 50%, the fibers still have comparable electrical conductivities, while the breakage elongation greatly increases from less than 6% to higher than 20%, and the fibers with 50% TiO2 have excellent tensile recovery within 15% strain. With TiO2 combined, the fibers have extra functional properties in photoelectric response, which can be further improved by oxygen plasma etching, and no obvious decay is observed even after 100 bending cycles. This study provides useful guidelines for designing of functional conductive graphene fibers with highly stretchable performance towards future uses.