Nickel oxide/carbon nanotube nanocomposites prepared by atomic layer deposition for electrochemical sensing of hydroquinone and catechol

The fabrication of nickel oxide/carbon nanotube (NiO/CNT) nanocomposites by atomic layer deposition (ALD) and their electrochemical performances for sensing hydroquinone (HQ) and catechol (CC) were investigated. NiO nanopaticles with a size of ~   4.9   nm formed by ALD were highly dispersed on the wall of pristine CNT. Then, the prepared NiO/CNT nanocomposites were used to modify glassy carbon electrode (NiO/CNT/GCE) for electrochemical detection , which presented enhanced electrochemical performances towards detecting HQ and CC. Not only were the redox peak currents of HQ and CC greatly enhanced, but also the oxidization peaks of the both phenolic isomers could be well separated. Under the optimized conditions, the current responses are linear for HQ and CC in the range of 10–500   μM and 10–400   μM, with detection limit of 2.5   μM (S/N   =   3) for both compounds.