Conducting polymer-inorganic nanocomposite-based gas sensors: a review

Abstract

With the rapid development of conductive polymers, they have shown great potential in room-temperature chemical gas detection, as their electrical conductivity can be changed upon exposure to oxidative or reductive gas molecules at room temperature. However, due to their relatively low conductivity and high affinity toward volatile organic compounds and water molecules, they always exhibit low sensitivity, poor stability, and gas selectivity, which hinder their practical gas sensor applications. In addition, inorganic sensitive materials show totally different advantages in gas sensors, such as high sensitivity, fast response to low concentration analytes, high surface area, and versatile surface chemistry, which could complement the conducting polymers in terms of the sensing characteristics. It seems to be a win-win choice to combine inorganic sensitive materials with polymers for gas detection due to their synergistic effects, which has attracted extensive interests in gas-sensing applications. In this review, we summarize the recent development in polymer-inorganic nanocomposite based gas sensors. The roles of inorganic nanomaterials in improving the gas-sensing performances of conducting polymers are introduced and the progress of conducting polymer-inorganic nanocomposites including metal oxides, metal, carbon (carbon nanotube, graphene), and ternary composites are presented. Finally, a conclusion and a perspective in the field of gas sensors incorporating conducting polymer-inorganic nanocomposite are summarized.

Printable G‐Putty for Frequency‐ and Rate‐Independent, High‐Performance Strain Sensors

“…Such sensors are important for a number of applications with particular attention being given to soft, wearable sensors which can monitor vital signs such as pulse and breathing. [1] In recent years nanocomposites, [2] generally consisting of 1D or 2D nanomaterials embedded in polymer matrices, have proven to be versatile materials and have been utilised in a number of end applications such as gas [3], chemical [4], thermal [5] and biological [6] sensing. In addition to this, polymer nanocomposites have been heavily studied as strain sensors [7,8,9].…”

Novel, Low Cost and Fast Detection Sensor for Biogenic H2S Gas Based on Polyaniline/ZnO, CdO and CeO2 nanocomposites at Room Temperature

“…As a result, it can be seen that the prepared nano composites have high sensitivity with short response times comparing to the pure polymer, proving that the introducing of metal oxides into the polymer matrix improve its conductivity properties [49]. This result confirmed that the sensors responded quickly to both the induction and removal of the H2S gas.…”

VOCs Sensing by Metal Oxides, Conductive Polymers, and Carbon-Based Materials

“…This charge transfer is generally transduced in conductivity changes that enable the gas/vapor detection even at room temperature, circumventing the need for thermal activation as in MOXs. Conductive polymers such as polypyrrole (PPy), polyaniline (PANI), polythiophene (PTh), and poly(3,4-ethylenedioxythiophene) (PEDOT), and their modifications with metals have been the most studied candidates for sensing VOCs [ 4 , 7 ] ( Figure 1 a). These materials demonstrated mostly resistive responses to vapors such as ethanol, methanol, and acetone, and gases such as NH 3 , NO 2 , and CO [ 5 ].…”

“…The sensing properties of these materials generally depend on the chemisorption of negatively charged oxygen adsorbates (O −2 , O − , and O 2− ) in air, which, due to charge transfer between the material and the analytes, change the electron density on the material surface. They may also depend on the chemical reaction between the sensitive material and the analyte, or the diffusion of species into the bulk of the material [ 1 , 2 , 3 , 4 , 5 , 6 , 7 , 8 , 9 , 10 ].…”