Bamboo-like carbon nanotube composites containing cobalt nanoparticles combined with imidazole-based ionic liquids enhance the performance of oxygen sensors

Abstract

Ionic liquids have excellent physical and chemical properties, enabling them to be widely used in electrochemical oxygen sensors. In recent years, the preparation of modified materials and ionic liquids mixed to improve the oxygen sensitivity of sensors has become a hotspot. In this study, 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF₆), which is a liquid at room temperature, was successfully prepared by a simple one-pot method, and BMIMPF₆ reacts at different oxygen concentrations. Bamboo-like carbon nanotube (BCNT) composites containing cobalt nanoparticles derived from graphite phase carbon nitride (g-C₃N₄) were prepared and fully mixed with the ionic liquid to form the BCNT/Co + BMIMPF₆ composite. The electrochemical behavior of oxygen in the electrochemical sensor was studied. The results show that the response current and stability of the oxygen sensor based on the BCNT/Co + BMIMPF₆ composite are significantly improved, the sensitivity is 1.15 μA/[%O₂], the response time is 16 s, and the linearity is good.