Phenol determination on HDTMA-bentonite-based electrodes

► HDTMA-modified bentonites were tested as electrode materials in the electro-oxidation of phenol. ► The influences of the surfactant loading and pH of the supporting electrolyte were investigated. ► Rapid deactivation of electrodes occurred in an acidic environment. ► Good stability of the investigated electrodes was obtained in alkaline medium. ► The sensitivity toward phenol and stability of the electrodes was markedly improved with increasing HDTMA loading.