title: Exfoliation Solvent Dependent Plasmon Resonances in Two-Dimensional Sub-Stoichiometric Molybdenum Oxide Nanoflakes.
abstract: Few-layer two-dimensional (2D) molybdenum oxide nanoflakes are exfoliated using a grinding assisted liquid phase sonication exfoliation method. The sonication process is carried out in five different mixtures of water with both aprotic and protic solvents. We found that surface energy and solubility of mixtures play important roles in changing the thickness, lateral dimension, and synthetic yield of the nanoflakes. We demonstrate an increase in proton intercalation in 2D nanoflakes upon simulated solar light exposure. This results in substoichiometric flakes and a subsequent enhancement in free electron concentrations, producing plasmon resonances. Two plasmon resonance peaks associated with the thickness and the lateral dimension axes are observable in the samples, in which the plasmonic peak positions could be tuned by the choice of the solvent in exfoliating 2D molybdenum oxide. The extinction coefficients of the plasmonic absorption bands of 2D molybdenum oxide nanoflakes in all samples are found to be high (ε > 10(9) L mol(-1) cm(-1)). It is expected that the tunable plasmon resonances of 2D molybdenum oxide nanoflakes presented in this work can be used in future electronic, optical, and sensing devices.
authors.affiliation: School of Electrical and Computer Engineering, RMIT University , Melbourne 3001, Australia.
authors.forename: Manal M Y A
authors.initials: MM
authors.lastname: Alsaif
authors.affiliation: RMIT Microscopy and Microanalysis Facility, RMIT University , Melbourne 3001, Australia.
authors.forename: Matthew R
authors.initials: MR
authors.lastname: Field
authors.affiliation: School of Electrical and Computer Engineering, RMIT University , Melbourne 3001, Australia.
authors.forename: Torben
authors.initials: T
authors.lastname: Daeneke
authors.affiliation: School of Electrical and Computer Engineering, RMIT University , Melbourne 3001, Australia.|Institute of Chemical and Bioengineering, Department of Chemistry and Applied Biosciences, ETH Zürich , Zürich 8092, Switzerland.
authors.forename: Adam F
authors.initials: AF
authors.lastname: Chrimes
authors.affiliation: School of Electrical and Computer Engineering, RMIT University , Melbourne 3001, Australia.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhang
authors.affiliation: School of Electrical and Computer Engineering, RMIT University , Melbourne 3001, Australia.
authors.forename: Benjamin J
authors.initials: BJ
authors.lastname: Carey
authors.affiliation: School of Electrical and Computer Engineering, RMIT University , Melbourne 3001, Australia.
authors.forename: Kyle J
authors.initials: KJ
authors.lastname: Berean
authors.affiliation: Functional Materials and Microsystems Research Group, RMIT University , Melbourne 3001, Australia.
authors.forename: Sumeet
authors.initials: S
authors.lastname: Walia
authors.affiliation: School of Applied Sciences, RMIT University , Melbourne 3001, Australia.|CSIRO Manufacturing Flagship , Bayview Avenue, Clayton 3168, Australia.
authors.forename: Joel
authors.initials: J
authors.lastname: van Embden
authors.affiliation: Xi'an Institute of Electromechanical Information Technology , Xi'an 710000, China.
authors.forename: Baoyue
authors.initials: B
authors.lastname: Zhang
authors.affiliation: School of Applied Sciences, RMIT University , Melbourne 3001, Australia.
authors.forename: Kay
authors.initials: K
authors.lastname: Latham
authors.affiliation: School of Electrical and Computer Engineering, RMIT University , Melbourne 3001, Australia.
authors.forename: Kourosh
authors.initials: K
authors.lastname: Kalantar-Zadeh
authors.affiliation: School of Electrical and Computer Engineering, RMIT University , Melbourne 3001, Australia.
authors.forename: Jian Zhen
authors.initials: JZ
authors.lastname: Ou
keywords: biosensing; extinction coefficient; molybdenum oxide; plasmon resonance; solar light; two-dimensional