Ammonia Gas Sensing Behavior of Hybridization between Reduced Graphene Oxide and Gold Nanoparticles

Huynh Tran My Hoa,Hoai Phuong Pham,Quang Trung Tran,Tran Viet Cuong,Tuan Anh Doan,Hoang Hung Nguyen,Kang Jea Lee,Tran Quang Nguyen

doi:10.1155/2020/7680508

Huynh Tran My Hoa, Hoai Phuong Pham + Show 6 more

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https://doi.org/10.1155/2020/7680508

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Abstract

Stack and composite are the two ways of hybridization between gold nanoparticles (AuNPs) and reduced graphene oxide (rGO) which have been fabricated and tested the ability to detect NH3 gas at room temperature. The device based on the rGO-AuNP composite structure exhibited the highest response and the fastest response and recovery time compared to stack and bare rGO. The red shift of a resonant peak in the absorption spectra and the negative shift in the binding energy of 4f5/2 peak indicated that the remarkable NH3 gas-sensing properties of this composite are mainly attributed to a chemical bonding formed between AuNPs and rGO at the defective sites. This type of interaction facilitates the electron transfer from the defect states to the AuNP surface wherein it easily reacts with the oxygen molecules in the atmosphere to create oxygen absorbents. Consequently, NH3 not only reacts with sp3-hybridized atoms but also reacts primarily with oxygen absorbents on the surface of AuNPs, resulting in a better sensing behavior of composite samples.

Highlights

In the past few years, reduced graphene oxide has emerged as an alternative to graphene because it is possible to tailor and create “new functionalities” of graphene through defects and oxygen-containing functional groups [1]
It comes from the fact that the type of interactions between reduced graphene oxide (rGO) and noble metals vary from weak van der Waals to strong covalent bonding which makes a clear difference in the sensing activities of rGO-metal hybrid devices
We focus on fabricating two types of combinations of rGO and AuNPs such as layer-by-layer and composite to clarify the correlation between AuNPs and rGO

Summary

Introduction

In the past few years, reduced graphene oxide (rGO) has emerged as an alternative to graphene because it is possible to tailor and create “new functionalities” of graphene through defects and oxygen-containing functional groups [1]. Defects act as active sites in forming nanocomposites with noble metals by the process of hybridization. Choi et al synthesize rGO and deposit the Pd layer on the rGO surface by a sputtering process and thermal annealing; a NO2 gas sensor at RT was made from this Pd-rGO hybrid [6]. From these reports, it can be seen that the mechanism and performance of the sensor depend strongly on the metal used and the synthesis method. Several theoretical and experimental studies on the interaction between graphene and noble metals have been performed, but similar studies for the rGO-metal hybrid

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