Magnetic iron oxide nanoparticles decorated graphene for chemoresistive gas sensing: The particle size effects
Authors: Nguyen Viet Chien
Nguyen Van Hieu
Dusan Losic
Tran Thanh Tung
Diana N H Tran
Campbell J Coghlan
Nguyen Van Duy
Md Julker Nine
Journal: Journal of Colloid and Interface Science (2019)
Discipline: CHEMISTRY
Keywords: Chemoresistive sensor; Gas sensor; Graphene; Hybrid material; Magnetic particles.
Affiliations: School of Chemical Engineering, The University of Adelaide, Adelaide, SA 5005, Australia; ARC Research Hub for Graphene Enabled Industry Transformation, The University of Adelaide, Adelaide, SA 5005, Australia., International Training Institute for Materials Science, Hanoi University of Science and Technology, No. 1, Dai Co Viet, Hanoi, Viet Nam., Faculty of Electrical and Electronic Engineering, Phenikaa Institute for Advanced Study (TIAS), Phenikaa University, Yen Nghia, Ha-Dong District, Hanoi 10000, Viet Nam; Phenikaa Research and Technology Institute (PRATI), A&A Green Phoenix Group, 167 Hoang Ngan, Hanoi 10000, Viet Nam. Electronic address: ., School of Chemical Engineering, The University of Adelaide, Adelaide, SA 5005, Australia; ARC Research Hub for Graphene Enabled Industry Transformation, The University of Adelaide, Adelaide, SA 5005, Australia. Electronic address: .

Abstract:  We report a synthesis of magnetic nanoparticles chemically immobilized onto reduced graphene oxide sheets (referred to as rGO-Fe3O4 NPs) as a gas and vapor sensing platform with precisely designed particle size of 5, 10 and 20 nm to explore their influence of particle size on sensing performance. The rGO-Fe3O4 NP sensors have been investigated their responses to different gases and volatile organic compounds (VOCs) at part-per-million (ppm) levels. Results show that the Fe3O4 NPs with smaller size (5 and 10 nm) on the rGO surface led to a lower sensitivity, while particles of a size of 20 nm have a significant enhancement of sensitivity compared to the bare rGO sensor. The rGO-Fe3O4 NP20 sensor can detect trace amounts of NO2 gas and ethanol vapor at the 1 ppm and is highly selective to the NO2 and ethanol among other tested gases and VOCs, respectively. The particle size causes different distribution behaviour of NPs over rGO surface and interspaced between them, which results in deceased or increased the surface interactions between gas and graphene. The NPs themselves contained different defects level and the charge depletion layer that affect their adsorption gas/vapor molecules, which are explained for different sensing responses. 

Retracted: No

PubPeer comments:
 Brought to my attention by a reader. Figure 4. * Pink boxes: the black, blue, and red graphs in panel a (bare rGO) look very similar to the black, blue, and red graphs in panel g (rGO-Fe3O4 NP20), respectively. * Green boxes: the blue and red graphs in panel c (hybridized rGO-Fe3O4 NP5) look very similar to the blue and red graphs in panel e (rGO-Fe3O4 NP10), respectively. ![file] , 
 Dear PUBPEER, Thank you very much for pointing out a mistake regarding Figure similarity in our publication. We have carefully checked out data and run again tests and agreed that we need to correct the Figure 4. We will contact the editorial office of the journal to request for correction shortly. We apologize for any inconvenience that may have caused you. Kind regards, Prof Losic On behalf of all authors , 
 #2 Prof losic, I am impressed with the kind of response. Science when in error needs corrections which rarely authors willing to address. , 
 ![file] Please find corrected Fig. 4 We again appreciate comments from the reader. , 
 The correction is included as Corrigendum in Journal. The link is enclosed https: www.sciencedirect.com science article pii S0021979721023171?dgcid=author![file] ,