Fe-Doped CuO/MWCNT as a Sensing Material for Electrochemical Detection of Nitrite

With unique electrical and catalytic properties, CuO has been ubiquitously employed in many applications including electrochemical sensors. Enhanced electrocatalytic performance of CuO can be achieved through doping. This work explored the potential of 3 mol% Fe-doped CuO/multi-walled carbon nanotube (MWCNT) composite for nitrite detection. The undoped CuO and 3 mol% Fe-doped CuO powders, prepared using a solution combustion technique, had average particle sizes lower than 100 nanometres. Particle refinement and enhancement of the specific surface area were observed in 3 mol% Fe-doped CuO. CuO/MWCNT and 3 mol% Fe-doped CuO/MWCNT composites, prepared using the hydrothermal impregnation technique, were tested for their electrocatalytic activities in the presence of nitrite. Cyclic voltammetry results revealed reduction reaction at an applied voltage of approximately -0.4 V. Superior peak currents were evident in the 3 mol% Fe-doped CuO/MWCNT composite. With acceptable sensitivity, limit of detection, selectivity, reusability, and recovery percentage, the 3 mol% Fe-doped CuO/MWCNT composite demonstrated potential capability in the detection of nitrite.