Reduced Graphene Oxide/Copper Nanoparticle Composites as Electrochemical Sensor Materials for Nitrate Detection
M. Sookhakian, Mohd Asri Mat Teridi, Goh Boon Tong, Pei Meng Woi, Munawar Khalil, Yatimah Alias
Abstract
An efficient electrochemical nitrate (NO3–) sensor consisting of a copper nanoparticle-reduced graphene oxide composite (Cu-rGO) with different rGO loadings was fabricated on indium tin oxide glass (ITO) by simple one-pot electrochemical deposition. The one-pot electrochemical deposition allows for the formation of Cu nanoparticles, reduction of graphene oxide, and decoration of Cu nanoparticles onto the rGO surface simultaneously. The as-electrochemically deposited Cu-rGO-modified ITO electrode was characterized using X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The effect of rGO on the electrocatalytic activity of the Cu-rGO-modified ITO electrode toward NO3– reduction was investigated. The Cu-rGO composite with 0.5 mg mL–1 rGO loading shows better sensitivity, a lower detection limit, and a wide linear detection range. Finally, the Cu-rGO-modified ITO electrode with 0.5 mg mL–1 rGO loading was used to measure nitrate in real samples.