Metal-Organic-Frameworks: Low Temperature Gas Sensing and Air Quality Monitoring

Xiaohu Chen,Darren Bagnall,Reza Behboodian,Noushin Nasiri,Mahdiar Taheri

doi:10.3390/chemosensors9110316

Abstract

As an emerging class of hybrid nanoporous materials, metal-organic frameworks (MOFs) have attracted significant attention as promising multifunctional building blocks for the development of highly sensitive and selective gas sensors due to their unique properties, such as large surface area, highly diversified structures, functionalizable sites and specific adsorption affinities. Here, we provide a review of recent advances in the design and fabrication of MOF nanomaterials for the low-temperature detection of different gases for air quality and environmental monitoring applications. The impact of key structural parameters including surface morphologies, metal nodes, organic linkers and functional groups on the sensing performance of state-of-the-art sensing technologies are discussed. This review is concluded by summarising achievements and current challenges, providing a future perspective for the development of the next generation of MOF-based nanostructured materials for low-temperature detection of gas molecules in real-world environments.

Highlights

In recent decades, the rapid growth of urban populations has resulted in new public health concerns and environmental pollution [1,2], and the fast monitoring of air- and waterborne contaminants using effective sensors has grown considerably in importance [1,3].An effective sensor should interact with the target analyte selectively with high sensitivity and short response time [2,4,5,6]
The results showed outstanding detection sensitivity to SO2 down to 75 ppb (Figure 6e) with a lower detection limit of 5 ppb and excellent selectivity towards SO2 compared to other gases with slight cross-selectivity with CO2
Stassen et al [104] reported the fabrication of an ambient CO2 chemoresistor platform based on nanoporous, electrically conducting 2D metal-organic frameworks (MOFs) deposited on Al2 O3 substrates featuring interdigitated electrodes (IDEs)

Summary

Introduction

The rapid growth of urban populations has resulted in new public health concerns and environmental pollution [1,2], and the fast monitoring of air- and waterborne contaminants using effective sensors has grown considerably in importance [1,3]. Chemoresistive-based gas sensors provide a superior sensing response at room temperature compared to optical-based gas sensors Their slow response dynamic at low/room operating temperature and their lack of selectivity towards target gases hinder their real-world application [4,5,6]. The development of nanostructures and nanocomposites of metal oxide sensors has further improved device sensing characteristics Despite these advantages and improvements, high operating temperature and inadequate gas selectivity have hindered substantial growth into new markets [61,63,64]. We conclude with a review of the rapidly emerging trends and promising strategies that can enhance functionality and enable the production of the generation of highly sensitive and selective MOF-based gas sensors for the low-temperature detection of gas molecules

Resistance decreased from

Findings

Summary and Outlook