Layered Double Hydroxide Functioned as a Novel Template for the Synthesis of Graphene-Oxide-Like Biochar and Enhanced Electrochemical Performances

Biochar was widely used in electrochemical applications. However, the structure of biochar usually needed a regulation before reaching a reasonable performance. In order to control the graphitization degree of biochar, a layered double hydroxide (LDH) was used as a template. In brief, biomass and a monolayer of LDH were assembled to form a hybrid. The pyrolyzed biochar was then applied as a supercapacitor after removing the template. As a result, the specific area of the regulated biochar increased from 128.795 to 708.658 m(2) g(-1). The graphitization degree increased significantly because the I-D/I-G was decreased from 1.82 to 1.02. Consequently, the regulated biochar had a specific capacitance of 238.57 F g(-1), which was five times higher than that of the unregulated one. Moreover, the regulated biochar kept 85% of initial capacitance after 5000 cycles. The mechanism investigation revealed that the template had a spatial confinement effect on interlayer biomass/organic. Therefore, the biochar was close to graphene oxide. These results put forward an effective method to increase the electrochemical property of biomass-derived functional materials.