Effect of MWCNT loading on the morphological, optical and electrical properties of Nickel phtalocyanine based composites

Abstract We report on the investigation of the surface morphology, optical and electrical properties of nanocompsite films from multiwalled carbon nanotubes (MWCNT) dispersed in nickel phthalocyanine (NiPc) with different amounts. We have explored the surface morphology of the films by using fractal concepts. The NiPc:MWCNT films were found to have a fractal dimension of ca. 2, indicating a quasi Euclidean surface. An increase in the wetting contact angle of NiPc:MWCNT films with MWCNT concentrations was observed. AC conductivity and dielectric properties of NiPc:MWCNT nanohybrids were measured at 100 Hz–13 MHz at room temperature. Upon increasing the concentration of MWCNT an increase in the AC conductivity is observed. The variation of AC conductivity with frequency has been described by the power law. The introduction of the concept of Constant Phase Element into the equivalent circuit model gave a fit in good agreement with the experimental data and implied the influence of a fractal interface on the real capacitance. The evolution of the electrical parameters with frequency and bias voltage of these composite-based systems has been discussed. Finally, the optimum composite proportion for high electrode sensitivity was tested by means of the electrochemical impedance spectroscopy for detection of Bisphenol A.