Abstract
The adsorption of 4-chlorophenol (4-CP) from an aqueous solution on three ordered mesoporous silica materials (commercial unmodified SBA-15-Sigma, synthesized unmodified SBA-15 and amino-functionalized SBA-15-NH2) was studied. The adsorption isotherms were analyzed using the Generalized Langmuir equation taking into account the energetic heterogeneity. The adsorption capacities of the mesoporous silicas increased in order: SBA-15 < SBA-15-Sigma < SBA-15-NH2. The materials were used for the modification of the carbon paste electrodes (CPEs) for detection of 4-CP based on differential pulse voltammetry. Different parameters that affects the DPV signal such as scan rate, accumulation time and paste composition were investigated. Compared with the bare (graphite) CPE, the SBA-15 modified electrodes greatly increased the oxidation peak current of 4-CP, showing strong signal enhancement effects. The SBA-15-NH2 modified CPE showed a larger peak current and higher sensitivity for the 4-CP in comparison with the SBA-15 and SBA-15-Sigma modified carbon paste electrodes. The results showed high usefulness of the ordered mesoporous silica materials as an electrode modifiers in the electroanalytical techniques.
Highlights
Mesoporous silica materials are characterized by high values of specific surface area, large pore volume and their pore structure consists of uniform canals formed in regular space networks
This paper describes the adsorptive properties of three ordered mesoporous silicas SBA-15 and their usefulness as modifiers of the carbon paste electrodes (CPEs) for detection of 4-chlorophenol
The adsorption isotherms of the 4-CP on the mesoporous silicas were analyzed using the Generalized Langmuir model, and its simplest form—Langmuir equation was found as the best model for analysis of the studied experimental systems
Summary
Mesoporous silica materials are characterized by high values of specific surface area, large pore volume and their pore structure consists of uniform canals formed in regular space networks. Mesoporous materials (unmodified as well as functionalized) have been used as carbon paste electrode (CPE) modifiers. DPV is extremely useful to detect trace levels of organic and inorganic analytes. In this technique, there are a series of regular voltage pulses superimposed on the potential linear sweep or stair steps. This paper describes the application of SBA-15 mesoporous materials as the modifiers of carbon paste electrodes. The best conditions for a differential pulse voltammetric (DPV) procedure were optimized and the modified CPEs were applied in the detection of 4-chlorophenol. The detection and determination of 4-CP using ordered mesoporous silica SBA-15 modified CPEs has not yet been reported
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
