Physicochemical and electrochemical properties of mesoporous silica carbon electrode / Noramira Saad

Lack of explanation in correlation between materials structure and the electrochemical
behaviours becoming a growing concern. In this study, the aims are to synthesise and

characterise the physical properties of the mesoporous silica Santa Barbara Amorphous-
15 and -16 (SBA-15 and SBA-16) and, followed by fabrication of mesoporous silica-
carbon electrode (MCPE) and investigate the electrochemical behaviours. The

mesoporous SBA-15 and SBA-16 were synthesized via surfactant templating approach
using triblock copolymer P123 and F127 as directing agent and tetraethyl orthosilicate
(TEOS) as silica source. The synthesized materials were characterized by X-ray
diffraction (XRD), infra-red spectroscopy (IR), thermal gravimetric analysis (TGA),
scanning electron microscopy (SEM) and nitrogen absorption-desorption tests. The
pore diameters were 5.5 nm and 3.2 nm for SBA-15 and SBA-16 respectively,
determined with BJH method based on adsorption data. Three different electrodes were
fabricated, carbon paste electron (CPE) and two modified carbon paste electrodes
(MCPE): SBA-15/MPCE and SBA-16/MPCE. The fabricated electrodes were tested
using cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The
addition of mesoporous silica to the carbon electrode improved the electrochemical
behaviors of the electrode formation of microelectrode thus enhanced migration of the
electrons. The SBA-16/MCPE showed better adsorption, response signal and a lower
resistance compare to SBA-15/MCPE due to 3D cubic structure of SBA-16 which
provide better electron pathway than SBA-15 2D hexagonal structure.