Fig. 8From: Electrochemical degradation of methylene blue accompanied with the reduction of CO2 by using carbon nanotubes grown on carbon fiber electrodesEffect of initial concentration of MB on the efficiency of electrochemical degradation by using CNTs/CFM as both cathode and anode under an applied current of 50 mA and electrolyte of 0.1 M H2SO4 (initial pH value of 1.83). Initial MB concentration of △: 5 mg L− 1; ◇: 10 mg L− 1; ▢: 15 mg L− 1 and ○: 20 mg L− 1Back to article page