Lee Junqiao, Hussain Ghulam, Banks Craig E, Silvester Debbie S
Curtin Institute for Functional Molecules and Interfaces & Department of Chemistry, Curtin University, GPO Box U1987, Perth, WA 6845, Australia.
Faculty of Science and Engineering, Manchester Metropolitan University, Chester Street, Manchester M1 5GD, UK.
Sensors (Basel). 2017 Nov 26;17(12):2734. doi: 10.3390/s17122734.
Screen-printed graphite electrodes (SPGEs) have been used for the first time as platforms to detect oxygen gas in room-temperature ionic liquids (RTILs). Up until now, carbon-based SPEs have shown inferior behaviour compared to platinum and gold SPEs for gas sensing with RTIL solvents. The electrochemical reduction of oxygen (O₂) in a range of RTILs has therefore been explored on home-made SPGEs, and is compared to the behaviour on commercially-available carbon SPEs (C-SPEs). Six common RTILs are initially employed for O₂ detection using cyclic voltammetry (CV), and two RTILs ([C₂mim][NTf₂] and [C₄mim][PF₆]) chosen for further detailed analytical studies. Long-term chronoamperometry (LTCA) was also performed to test the ability of the sensor surface for real-time gas monitoring. Both CV and LTCA gave linear calibration graphs-for CV in the 10-100% vol. range, and for LTCA in the 0.1-20% vol. range-on the SPGE. The responses on the SPGE were far superior to the commercial C-SPEs; more instability in the electrochemical responses were observed on the C-SPEs, together with some breaking-up or dissolution of the electrode surface materials. This study highlights that not all screen-printed ink formulations are compatible with RTIL solvents for longer-term electrochemical experiments, and that the choice of RTIL is also important. Overall, the low-cost SPGEs appear to be promising platforms for the detection of O₂, particularly in [C₄mim][PF₆].
丝网印刷石墨电极(SPGEs)首次被用作检测室温离子液体(RTILs)中氧气的平台。到目前为止,在使用RTIL溶剂进行气体传感方面,碳基SPEs与铂和金SPEs相比表现较差。因此,研究了一系列RTILs中氧气(O₂)在自制SPGEs上的电化学还原,并与市售碳SPEs(C-SPEs)上的行为进行了比较。最初使用六种常见的RTILs通过循环伏安法(CV)检测O₂,并选择两种RTILs([C₂mim][NTf₂]和[C₄mim][PF₆])进行进一步详细的分析研究。还进行了长期计时电流法(LTCA)以测试传感器表面进行实时气体监测的能力。CV和LTCA在SPGE上均给出了线性校准曲线——CV在10 - 100%体积范围内,LTCA在0.1 - 20%体积范围内。SPGE上的响应远优于商业C-SPEs;在C-SPEs上观察到电化学响应更不稳定,同时电极表面材料出现一些破裂或溶解。这项研究强调,并非所有丝网印刷油墨配方都与RTIL溶剂兼容以进行长期电化学实验,并且RTIL的选择也很重要。总体而言,低成本的SPGEs似乎是检测O₂的有前景的平台,特别是在[C₄mim][PF₆]中。