The carbon cloth/Fe2O3 (CC/Fe2O3) was prepared by a
catalyst and surfactant-free hydrothermal method. Typically,
35.0 mmol Fe(NO3)3 9H2O and 35.0 mmol Na2SO4
were dissolved into a mixture with 640.0 mL H2O. Then, a
piece of carbon cloth (31.00 14.50 cm2
) cleaned by deionized
water and ethanol was immersed in that mixed
solution for 30 min. Next, they were transferred into one
800 mL of Teflon-lined stainless autoclave. Subsequently,
the autoclave was sealed and heated in an electric oven at
120.0 1C for 6.0 h. Then, the as-prepared sample was
collected, washed with deionized water and ethanol for
several times, vacuum dried at 60 1C. At last, the composite
was annealed in air at a relatively low temperature of
450.0 1C for 2.0 h with 2 1C min1 heating rate. To study the
effect of the amount of Fe2O3 on the supercapacitive
performance, we adjusted the content of Fe2O3 in the
nanocomposites by adding different amounts of Fe
(NO3)3 9H2O and Na2SO4 in the hydrothermal process. To
easily discriminate these samples, the control samples with
different amounts of Fe2O3 coating on the carbon cloth was
denoted as CC/Fe2O3−x (x=1 and 2, standing for 26.25 and
43.75 mmol Fe(NO3)3 9 H2O/Na2SO4 used in the synthesis).