chapter  Chapter 11
22 Pages

Influence of Cationic, Anionic, and Nonionic Surfactants on Hydrothermal Synthesis of Nano Cus: Structural, Morphological, and Capacitance Behavior

WithD. Geetha, P.S. Ramesh, Surekha Podili

A different ionic surfactant was used in a typical hydrothermal process for controlling the morphology of the CuS nanostructure. Here in we demonstrate the synthesis and formation mechanism of CuS nanostructures by a simple hydrothermal route using organic surfactants anionic, cationic, and non-ionic surfactants as templates and thiourea as the sulfur source in 130ºC. The effect of cationic cetyltrimethylammonium bromide (CTAB), anionic sodium dodecyl benzene sulphonate (SDBS) and nonionic (Triton X–100) surfactants for adjusting the shape/size, porosity, and electro-chemical properties of CuS nanostructures was examined. The as-obtained CuS were characterized by XRD, FT-IR, UV-Vis, SEM/EDS, TEM, XPS, and cyclic voltammetry (CV). The XRD pattern reveals that the obtained nanostructures are crystalline in nature. The effect of surfactants on the 192morphology of the CuS shows that the diameter of the product in the range of 7–14 nm for (0.1 mM) CTAB stabilized CuS, 12–27 nm for (0.1 mM) SDBS stabilized CuS and 9–32 nm for (0.1 mM) Triton X–100 stabilized CuS. The result of electrochemical measurements by cyclic voltammetry shows that the specific capacitance value changes with the stabilizing agents and porous nature of the samples. The specific capacitance values were found to increase in the order of CuS – Triton X–100 (164.47Fg−1) < CuS – SDBS (257.13Fg−1) < CuS-CTAB (328.26 Fg−1) at a scan rate of 5 mV per second in 2 M KOH aqueous electrolyte solution. The electrochemical measurement shows that the specific surface area and capacitance changes with the ionic nature of the surfactant. Among these electrodes, the CuS electrode show an using specific capacitance 328.26 Fg−1 with mass loading (1.5 mg/cm3), good power capability, excellent cycling stability and high columbic efficiency. This exceptional performance is benefited from the almost mono dispersed morphology and high specific surface area. At the same time, the supercapacitor, employing the CuS electrode with porous nanostructure as the positive electrode and the activated carbon electrode as the negative electrode was successfully assembled.