Synthesis of sustainable lignin-derived mesoporous carbon for supercapacitors using a nano-sized MgO template coupled with Pluronic F127

Abstract

Herein, we describe the synthesis of meso-structured carbon from residual pre-cross-linked lignin from a wheat straw alkaline pulping process by employing nano-sized MgO and Pluronic F127 as templates. MgO nano-particles function as substrates and the main template by a space occupying effect, while F127 works as a dispersant preventing the agglomeration of MgO as well as a soft templating agent. To the best of our knowledge, no work concerning the synthesis of lignin-derived mesoporous carbon via a MgO template route has been reported. The mass ratio of lignin/MgO plays a major role in enriching the porosity of the carbon. Vacuum drying and freeze-drying technologies were applied during solvent evaporation to ensure the Mg template can be dispersed sufficiently. The Brunauer–Emmett–Teller specific surface area and total pore volume can reach 712 m² g⁻¹ and 0.90 cm³ g⁻¹, with a mesopore content of over 83%. The electrochemical performance of the obtained carbons as supercapacitor electrode materials was investigated. Although the vacuum environment enhanced the porosity and pore uniformity, the corresponding carbon didn't exhibit better electrochemical behavior than the carbon derived without a vacuum environment.