growth of lignin-based graphene-like films catalyzed by metal substrates

Lignin is expected to replace traditional fossil energy and convert it into a carbon material with excellent performance because of its advantages of being green and renewable, and its abundant reserves that are cheap and easy to obtain. The substitution of lignin for petroleum-based materials can not only effectively realize the high-value utilization of biomass, but reduce environmental pollution and energy loss. This work reported a simple and relatively low-temperature method to produce lignin-based graphene-like carbon materials. In this study, a lignin-based graphene-like film with micron thickness was successfully prepared by carbonization at a relatively low temperature (800 °C) using alkali lignin (AL) as a solid carbon source and large-area metal Ni sheets as catalyst. Through a series of characterization studies of the obtained products at different temperatures, the structural changes of AL and the growth process of the crystal nucleus are further explained. Moreover, the lattice fringes in few-layer graphene were observed by high resolution transmission electron microscopy, which showed that graphitic carbon structures are formed under the catalysis of metal Ni sheets. To sum up, the process was simple and low in energy consumption, and successfully converted biomass resource AL into high value-added carbon material products, alleviating the current problems of energy consumption and climate pollution. Biomass resource lignin was used to construct a large-scale and ordered lignin graphitization structure in a two-dimensional space through the catalytic graphitization process, forming a lignin-based graphene-like film with conductivity.