Hybrid electrolytes based on ionic liquids and amorphous porous silicon nanoparticles: Organization and electrochemical properties
El Demellawi, Jehad K.
Duran Retamal, Jose Ramon
KAUST DepartmentPhysical Sciences and Engineering (PSE) Division
KAUST Catalysis Center (KCC)
Computer, Electrical and Mathematical Sciences and Engineering (CEMSE) Division
Biological and Environmental Sciences and Engineering (BESE) Division
Permanent link to this recordhttp://hdl.handle.net/10754/623843
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AbstractIonic liquids (ILs) and ionic liquid-nanoparticle (IL-NP) hybrid electrolytes have garnered a lot of interest due to their unique properties that stimulate their use in various applications. Herein, we investigate the electrochemical and photo-physical properties of organic-inorganic hybrid electrolytes based on three imidazolium-based ionic liquids, i.e., 1-buthyl-3-methylimidazolium thiocyanate ([bmim] [SCN]), 1-ethyl-3-methylimidazolium tetrafluoroborate ([emim] [BF4]) and 1-buthyl-3-methylimidazolium acetate ([bmim] [Ac]) that are covalently tethered to amorphous porous silicon nanoparticles (ap-Si NPs). We found that the addition of ap-Si NPs confer to the ILs a pronounced boost in the electrocatalytic activity, and in mixtures of ap-Si NPs and [bmim] [SCN], the room-temperature current transport is enhanced by more than 5 times compared to bare [bmim] [SCN]. A detailed structural investigation by transmission electron microscope (TEM) showed that the ap-Si NPs were well dispersed, stabilized and highly aggregated in [bmim] [SCN], [emim] [BF4] and [bmim] [Ac] ILs, respectively. These observations correlate well with the enhanced current transport observed in ap-Si NPs/[bmim] [SCN] evidenced by electrochemical measurements. We interpreted these observations by the use of UV–vis absorbance, photoluminescence (PL), FTIR and solid-state NMR spectroscopy. We found that the ap-Si NPs/[bmim] [SCN] hybrid stands out due to its stability and optical transparency. This behavior is attributed to the iron(III) thiocyanate complexion as per the experimental findings. Furthermore, we found that the addition of NPs to [emim] [BF4] alters the equilibrium of the IL, which consequently improved the stability of the NPs through intermolecular interactions with the two ionic layers (anionic and cationic layers) of the IL. While in the case of [bmim] [Ac], the dispersion of ap-Si NPs was restrained because of the high viscosity of this IL.
CitationTchalala MR, El-Demellawi JK, Abou-Hamad E, Retamal JRD, Varadhan P, et al. (2017) Hybrid electrolytes based on ionic liquids and amorphous porous silicon nanoparticles: Organization and electrochemical properties. Applied Materials Today 9: 10–20. Available: http://dx.doi.org/10.1016/j.apmt.2017.04.011.
SponsorsThe authors would like to thank King Abdullah University of Science and Technology (KAUST) for the financial support.
JournalApplied Materials Today