Single-Stream H<sub>2</sub>O<sub>2</sub> Membraneless Microfluidic Fuel Cell and Its Application as a Self-Powered Electrochemical Sensor
Zhenfei Liu, Dingding Ye, Shaolong Wang, Xun Zhu, Rong Chen, Qiang Liao
Abstract
A membraneless microfluidic fuel cell (MMFC) with a single stream in cotton threads, which exploits H2O2 as both fuel and oxidant, is developed in this study. Benefiting from the selective catalysis of H2O2, fuel crossover or diffusive mixing between fuel and oxidant can be neglected in this fuel cell. Besides, capillary combined with gravity forces are utilized to drive the reactant solution transport through cotton threads, and the external pump is no longer needed. The proposed fuel cell produces a maximum power density of 5.5 mW cm–2 with an open-circuit potential value of 0.66 V, which is greater than those of other H2O2 MMFCs reported before. To widen the application of the fuel cell, a self-powered H2O2 electrochemical sensor is further developed based on the proposed fuel cell structure. The presented sensor exhibits a wide linear detection range from 5 to 50 mM with a superior sensitivity of 0.0375 mA mM–1, a low limit of detection (LOD) of 1.44 mM (S/N = 3), a rapid response time, and good reproducibility. In addition to a new type of H2O2 sensor, the fuel cell also holds great promise as a micropower source for microelectronic devices and other electrochemical sensors.