Free‐Standing Functionalized Graphene Oxide Solid Electrolytes in Electrochemical Gas Sensors

Abstract

A free‐standing sulfonic acid functionalized graphene oxide (fSGO)‐based electrolyte film is prepared and used in an electrochemical gas sensor, an alcohol fuel cell sensor (AFCS), for the detection of alcohol. The fSGO electrolyte film‐based AFCS detects ethanol vapor with excellent response, linearity, and sensitivity, since it possesses a high proton conductivity (58 mS cm−1 at 55 °C). An ethanol detection limit level as low as 25 ppm is achieved and high selectivity for ethanol over acetone is demonstrated. These results do not only show the promising potential of fSGO films in an electrochemical gas sensors, specifically a portable breathalyzer, but also open an alternative pathway to investigate the application of graphene derivatives in the field of gas sensors.

Laminated Cross‐Linked Nanocellulose/Graphene Oxide Electrolyte for Flexible Rechargeable Zinc–Air Batteries

“…In the GO spectrum, the characteristic peaks are observed at 1739 cm (carbon-hydroxyl C-OH), 1054 cm −1 (epoxide C-O-C), 856 cm −1 (epoxy rings) and a broad band at 3200-3500 cm −1 (free hydroxyl O-H), which indicates abundant oxygen-containing groups on its basal planes and edges. [12,13] In the spectrum of QAFGO, after functionalization, the peaks assigned to the vibration of C O (1739 cm −1 ), C-OH (1224 cm −1 ), C-O-C (1054 cm −1 ), and epoxy rings (856 cm −1 ) disappear. [14] Alternatively, two new small peaks at 2852 and 2921 cm −1 emerge in the spectrum, owing to methyl and long chains of methylene groups in the precursor (DMAOP), which indicates the effective grafting reaction between the oxygen functional groups of GO and QA groups of DMAOP.…”

“…[9][10][11] To address these challenges, researchers have sought to highly efficient solid-state electrolytes based on graphene oxide (GO), the oxidation product of natural graphite flakes. [12][13][14] GO has been demonstrated as a promising candidate because of its outstanding physicochemical stability and electrochemical properties. [15] Additionally, GO is a well-known wileyonlinelibrary.com step 2, Supporting Information).…”

“…[12,16] Owing to the wide range of oxygen functional groups on its basal planes and edges, GO is also readily exfoliated to yield well-dispersed solution of individual GO sheets in both water and organic solvents, and then flow-directed assembled into a free-standing paper-like material by vacuum filtration. [12,17] However, despite all the progress of the development of a free-standing GO electrolyte membrane, its advantages are diminished with the difficulty to form a mechanically robust membrane. [17,18] Consequently, that makes the free-standing GO membranes less attractive for being used as practical solid-state electrolytes in energy storage systems.…”

Electric Power Generation through the Direct Interaction of Pristine Graphene‐Oxide with Water Molecules

“…This point is also confirmed in Figure e,f. The enhanced V oc output in Figure f can be attributed to the lower ionic resistance along the GO layer direction . The moisture‐adsorbed GOF system has some similarities with nanofluidics in 2D materials .…”

A highly sensitive breathable fuel cell gas sensor with nanocomposite solid electrolyte

“…First, high sensitivity makes electrochemical gas sensor suitable for low concentration detection in the ppm range . Also, the linear relationship between target gas concentration and generated electric current enables electrochemical gas sensor better accuracy and repeatability . Moreover, electrochemical gas sensor usually presents superior selectivity compared to semiconductive and thermal conductive gas sensors, and also has the ability to detect various gases by modifying the materials …”