Electrochemical and Microstructural Investigation of in-situ Grown CNTs Network on Carbon Paper as Electrocatalytic Electrode for Fuel Cells

In this study, carbon nanotubes (CNTs) were deposited directly on impregnated Fe/carbon paper (CP) substrate (CNT/CP) utilizing chemical vapor deposition (CVD) process with the aim of using them as electrocatalytic electrode. The influence of wet impregnation conditions and CVD growth parameters on the characteristics of CNTs was investigated. Field emission scanning electron microscopy (FESEM), Energy dispersive spectroscopy (EDS), Transmission electron microscopy (TEM) and Raman spectroscopy were applied to characterize nucleation, growth and morphology of CNTs on CP. Measurement of Contact angle (CA) determined 125.9 and 145.0 ⁰C for CP and CNT/CP that displayed an increase in water repellence and degree hydrophobicity of CNT/CP to 15% than CP. Electrochemical impedance spectroscopy (EIS) analysis indicated the reduction of electrode charge transfer resistance from 5000 ohm value from CNT/CP to ohm value for CP that shows the increment in electrical conductivity of CNTCP. Half-cell test analysis represented that the improvement of performance and the increase of power density to ⁓8 % for Pt/CNT/CP compared to commercial catalyst Pt/C/CP (20 wt%) even with about 42% less Pt loading, can be attributed to strong adhesion of in-situ CNTs to the CP and lower agglomeration of CNTs along with outstanding electrical and thermal conductivity of CNTs. The obtained results indicated that the proposed nanostructure serves as a promising candidate for many technological applications specially carbon nanotube-supported catalyst.