Chemically modified multiwalled carbon nanotube carbon paste electrode for copper determination

Abstract

A new Cu2+ carbon paste electrode based on incorporation of new CPE via chemically modified multiwalled carbon nanotube (CMMWCNT) on the graphite matrices has been constructed. The surface of MWCNT was modified by performing a coupled reaction between trimethoxysilylpropylethilendiamine (TMSPEDA) and 2-hydroxybenzaldehyde (2-HBA). This new material was characterized with different techniques such as FT-IR, SEM and BET analysis. The influence of variables including sodium tetraphenylborate (NaTPB), graphite powder, Nujol, amount of MWCNT–SPAEIMP and Ag nano particles loaded on AC on the electrode response was studied and optimized. At optimum values of variables set as carbon powder, carrier, NaTPB and Nujol, the response of Cu2+ selective electrodes in the absence and presence of Ag-NP-AC was linear in a concentration range of 5.0 × 10−6–1.0 × 10−1 and 5.0 × 10−7–1.0 × 10−1 mol L−1 with slope 29.93 and 29.11 mV and with detection limit of 3.2 × 10−6 and 2.5 × 10−7. The good performance of electrode viz. reasonable wide pH range (2.0–5.5), fast response time (<15 s) and adequate life time (2 months) in addition to low RSD (<4%) shows the utility of the proposed electrodes for Cu2+ ion content quantification in various situations. The moderate selectivity coefficient evaluated by the separation solution method (SSM) and fixed interference method (FIM) indicates efficiently the discriminating ability of proposed electrode for copper ion evaluation.