Highly ordered mesoporous carbons with high specific surface area from carbonated soft drink for supercapacitor application

Abstract

Abstract Highly ordered mesoporous carbon materials with a high surface area and tunable pore diameters and functionalized surfaces have been synthesized using 3D mesoporous silica with different pore diameters as templates and expired carbonated softdrink, Coca-Cola® as the sustainable and renewable source for carbon. The presence of carbonates and the chemicals in the soft drinks help to achieve both high porosity and functional groups on the surface of the final porous carbon products in a single step. Nitrogen adsorption and XRD results reveal that the obtained mesoporous carbon materials exhibit well-ordered porous structure and excellent textural properties such as high surface areas (1400–1810 m2 g−1), large pore volumes (1.45–2.81 cm3 g−1) and tunable pore sizes (3.5–5.2 nm). The presence of glucose and fructose together with the carbonate groups help to achieve a high porosity with both meso and micropores in the samples. It is found that the surface parameters can be easily controlled by tuning either the pore diameter of the template or the amount of the carbonated precursors. HRTEM and XRD results confirm a well-ordered mesoporous structure, similar to that of the templates. XPS and NEXAFS results confirmed the presence of nitrogen, oxygen and sulphur functionalities on the surface of the samples which may be useful for the electrochemical applications. The mesoporous carbon material with the highest specific surface area demonstrates excellent supercapacitance properties with the capacitance of 284 F g−1 at 1 A g−1 which is much higher than that of pristine mesoporous carbon CMK-3 with different pore diameters, nitrogen doped mesoporous carbons, multiwalled carbon nanotubes, and activated carbons. The sample also shows excellent electrochemical stability even after 1,000 cycles. The possible reason for the high capacitance with excellent cyclic ability is due to its high surface area, 3D mesoporous structure with a combination of both meso and micropores and highly dispersed nitrogen and oxygen functionalities.