Carbon Nanotubes Modified Carbon Cloth Cathode Electrode for Self-Pumping Enzymatic Biofuel Cell

Ngoc Bich Duong,Li Z Huang,Sheng L You,Hsiharng Yang

doi:10.1155/2018/8748731

Abstract

A self-pumping enzymatic biofuel cell (self-pumping EBC) with a new cathodic catalyst which was modified by coating the mixture of carbon nanotubes/caffeic acid (CNTs/CA) on a carbon cloth (CC) to form a CNTs/CA/CC cathode electrode was fabricated. By using UV spectrophotometer, the absorbance of CA, CNTs, and the CNTs/CA composite was observed. To evaluate how the CNTs/CA/CC cathodic electrode improves the electrochemical performance of the self-pumping EBC, the measurement of the redox reaction current peak by cyclic voltammetry (CV) was implemented. In accordance with CV measurement, the utilization of the modified CNTs/CA/CC cathodic electrode exhibited a higher oxygen reduction current peak at 319.1μA under the saturated oxygen. The anode and cathode flow rates were 0.416μls−1 and 0.844 μls−1 which contribute to obtaining the capillary driven liquid efficiency as 30% for the former and 59% for the latter. Moreover, the self-pumping EBC performance tests showed that the maximum power density (MPD) of the self-pumping EBC with the modified cathodic electrode achieved 0.592 mWcm−2 which improved 10% in the performance compared with the bare CC electrode, 0.534 mWcm−2.

Highlights

Biofuel cell converts chemical energy into electrical energy through a series of biochemical reactions by utilizing biocatalyst
According to the type of catalyst, the biofuel cell can be separated into the fuel cell as microbial biofuel cell (MBC) that uses micro bacteria to react for electricity and enzymatic biofuel cell (EBC) that employs enzymes as a catalyst to separate electrons from parent molecule and force it to go around an electrolyte barrier through a wire to generate an electric current
For preparing the cathodic electrode carbon nanotubes/caffeic acid (CNTs/Caffeic acid (CA))/carbon cloth (CC), after Carbon nanotubes (CNTs) was purified by the acidic treatment that was the mixture of the sulfuric acid (H2SO4) and nitric acid (HNO3) at the concentration of 3:1, 10 mM CA was combined with 10 mg/ml purified CNTs dissolved in 5 ml of ethanol solution and shaken by ultrasonic bath for 16 h

Summary

Introduction

Biofuel cell converts chemical energy into electrical energy through a series of biochemical reactions by utilizing biocatalyst. Yang [20] successfully turned out a new research direction that their fabricated EBC can drive fuel by itself through the capillary effect named self-pumping enzymatic fuel cell whose maximum power density was quite low. In this study, the selfpumping EBC is with a modified CC at the cathode and anode electrode CNTs/CA/CC and GOx[TPP/CS/CC], respectively, to enhance the self-pumping EBC’s electricity. Whether the CNTs/CA can improve the redox current as well as the power output of the self-pumping EBC through several methods such as UV spectrophotometer, CV measurement, and polarization test (Tafel test) was evaluated, and the performances of the selfpumping EBC were successfully investigated

Experimental

Results and Discussion

Conclusion