CoFe2O4- mesoporous carbons derived from Eucommia ulmoides wood for supercapacitors: Comparison of two activation method and composite carbons material synthesis method.

[Display omitted] • EUO- mesoporous ACs were produced from one-step and two-step chemical activation. • The structural characteristic of the porous carbon was comprehensively elucidated. • CoFe 2 O 4 was anchored on ACs by hydrothermal and chemical co-precipitation method. • Comparison of two activation method and composite carbons material synthesis method. • The maximum specific capacitance of AC-metal-composite can be reached 596.26 F/g. The mesoporous activated carbon (AC) was synthesized by low temperature phosphoric acid activation based on Eucommia ulmoides Oliver (EUO) wood (one-step) and EUO-charcoal (two-step). The pore structure, surface composition and graphitization degree of carbons synthesized by one-step and two-step activation were systematically investigated. The results exhibited that the specific surface area of porous carbon varies from 1264.8 m2/g (two-step activation, AC 2) to 1506.7 m2/g (one-step activation, AC 1), which indicated AC 1 gained more well-developed mesoporous structure (the mesoporous ratio reached 75.27 %) than that of AC 2. Besides, as CoFe 2 O 4 spinel-type metal oxides nanoparticles (NPs) were anchored on ACs by hydrothermal method and chemical co-precipitation, the electrochemistry characteristics were presented in a three-electrode system. As compared with the products (ACs/CF 2) prepared by chemical co-precipitation to prepared, AC 1 combined with CoFe 2 O 4 by hydrothermal method (AC 1 /CF 1) showed higher specific capacitance of 596.26 F/g (0.005 V/s), which was profited from the synergistic effect of double-layer capacitance and pseudo-capacitance, and the capacitance retention maintained 93.7 % after 10,000 cycles of charging-discharging at 2 A/g. Therefore, EUO wood is a promising feedstock for the preparation of porous carbon, its metal compound (ACs/CFs) provided excellent performance in potential supercapacitors applications, and by the means of the comparisons for the activation method and the scheme for combination of CoFe 2 O 4 , this study generated significative guidance for the preparation of activated carbon and its composite. [ABSTRACT FROM AUTHOR]