Gram‐Scale Synthesis of Porous Graphene via Printing Paper Pyrolysis as Supercapacitor Electrodes

Abstract

Graphene has great potential in the application as supercapacitor electrode materials owing to its unique properties. However, it is challenging to find a facile and cost‐efficient method using cheap raw materials for large‐scale synthesis. Herein, a simple method is demonstrated for converting printing paper to graphene via one‐step pyrolysis followed by washing. Various characterizations are used to analyze the obtained samples, revealing the typical graphene feature of the products. The sample obtained at 900 °C (denoted as G‐900) shows a specific surface area of 514 m 2 g −1 with a 50% mesopore volume. The symmetric supercapacitor using G‐900 as an active electrode material gives rise to an ultrahigh power density of 49 kW kg −1 at a high current density of 10 A g −1 , along with a great specific capacitance of 164.4 F g −1 . The capacitance retention ratio is as high as 93% after cycling for 4000 cycles at a current density of 1 A g −1 . As hundreds of million tons of paper are used annually, converting the waste paper to graphene is a scalable way for practical applications, associated with the facile conversion procedures.