Green Nanosilicas for Monoaromatic Hydrocarbons Removal from Air

Abdunaser M Ewlad-Ahmed,Michael Morris,Justin Holmes,Lorraine T Gibson,Siddharth V Patwardhan,David J Belton

doi:10.1007/s12633-020-00924-1

Abstract

We demonstrate a novel application of green nanosilicas (GN), prepared via an environmentally friendly route, in removing volatile organic compounds (VOCs). Herein, we aim to establish GN as viable alternatives to traditional mesoporous silicas for the removal of monoaromatic hydrocarbons (MAHC). The results show that the GN have high extraction efficiencies comparable to those previously reported for mesoporous silicas. It was demonstrated that bespoke GN can be syntheised readily with the ability to tailor their physical properties and MAHC adsorption. In order to understand the MAHC adsorption by GN, their porosity, morphology and pore structure were characterised. It was observed that the combination of broad pore size distribution and, in particular, the presence of meso- and micro-porosity in GN contributed to high MAHC extraction efficiencies and selectivity. Although from a commercial viewpoint, further optimisation of GN is desirable in order to replace traditional sorbents, this work clearly highlights a new family of “green” sorbents, which can be prepared with a substantial reduction in secondary pollution with potential applications in selective gas separation.Graphical New green nanoparticles (GN) have been developed as VOC adsorbents; GN preparation is rapid and under neutral pH and room temperature conditions, leading to a substantial reduction in secondary pollution. Their successful performance is related to their unique physical properties, which can be easily tailored.

Highlights

Porous materials are used in wide ranging applications such as catalysis, separations, detergents, biomedical devices, chemical sensors, electronic devices and many emerging technologies [1, 2]
Recent research has shown that mesoporous silicas such as MCM-41 are very efficient scavengers of larger volatile organic compounds (VOCs) like monoaromatic hydrocarbons (MAHC) when compared with industrial standards such as TenaxTM TA [18, 23]
The extraction efficiencies of green nanosilicas (GN) or MCM-41 adsorbents were carefully investigated for four VOCs – toluene, EB, cumene and DCB

Summary

Introduction

Porous materials are used in wide ranging applications such as catalysis, separations, detergents, biomedical devices, chemical sensors, electronic devices and many emerging technologies [1, 2]. Recent research has shown that mesoporous silicas such as MCM-41 are very efficient scavengers of larger VOCs like MAHC when compared with industrial standards such as TenaxTM TA [18, 23] Aromatic molecules such as benzene and toluene have shown strong interactions with silica surfaces [24] and with the ability to tune textural properties of porous silicas, VOC adsorption can be improved [25]. A recent review has concluded that functionalised mesoporous silicas are rapidly establishing as promising adsorbents for VOC capture [26] These materials are generally prepared under harsh conditions and require long procedures, e.g., elevated temperature, high pressure, strongly alkaline or acidic solutions with preparations taking several days [27,28,29]. It is clear that greener alternatives to such porous materials are required

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Results

Conclusion