An insight into the surface properties of calcined kaolinitic clays: The grinding effect

Gamelas, José A. F.; Ferraz, Eduardo; Rocha, Fernando

doi:10.1016/j.colsurfa.2014.04.038

Cited by 49 publications

(42 citation statements)

References 36 publications

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“…The dispersive surface energy was calculated using the Schultz method. 16,[21][22][23] Briefly, the retention of a gas probe molecule is quantified by the net retention volume, V n , defined as the amount of …”

Section: Resultsmentioning

confidence: 99%

Effects of high surface energy on lithium-ion intercalation properties of Ni-doped Li3VO4

et al. 2016

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Nickel was doped into Li 3 VO 4 (Ni-LVO) successfully via a facile room temperature reaction, and the resulting Ni-LVO nanocrystallites showed excellent lithium-ion storage properties with a capacity of 650 mAh g − 1 at 50 mAh g − 1 and excellent capacity stability as an anode in lithium-ion batteries, maintaining nearly 100% of the initial reversible capacity after 800 cycles at 1 A g − 1 . The superior electrochemical properties arose largely from the nickel doping in the Ni-LVO. The surface energy of the electrode material was analyzed by an inverse gas chromatography method, and the Ni-LVO surface energy, 43.91 mJ m − 2 , was much higher than the 30.74 mJ m − 2 of Li 3 VO 4 . X-ray photoelectron spectra results demonstrated that nickel doping promoted the formation of tetravalent vanadium ions, V 4+ , as well as a more amorphous surface of Li 3 VO 4 , thus probably resulting in more nucleation sites for the phase transformation and reduced activation energy of the redox reactions and phase transition during the lithium-ion intercalation/extraction processes. NPG Asia Materials (2016) 8, e287; doi:10.1038/am.2016.95; published online 22 July 2016 INTRODUCTION Li 3 VO 4 (LVO), whose structure consists of corner-sharing VO 4 and LiO 4 tetrahedra, has been studied as a promising anode material for lithium-ion batteries. 1,2 It possesses several advantages over other anode materials. First, LVO has a small structural and volume change during lithiation/delithiation processes, thus resulting in good cyclic durability. 3 Second, it has high ionic conductivity (~10 − 4 S cm − 1 ), which facilitates the effective diffusion of lithium ions in bulk. 4 Third, compared with Li 4 Ti 5 O 12 , LVO can intercalate lithium ions in a low-voltage region (between 0.5 and 1.0 V vs Li/Li + ), thus eventually offering a high full cell energy density and maintaining good safety. 3,5 Finally, the hollow, lantern-like, three-dimensional structure of LVO crystal provides many empty sites to accommodate lithium ions and serves as lithium ion insertion channels. Theoretical calculations indicate that the inserted lithium ions have two different Wyckoff sites, which are stably occupied by three external lithium ions corresponding to a theoretical capacity of 591 mAh g − 1 when discharged to 0.01 V vs Li/Li + . 6 Despite these advantages, LVO suffers from low electrical conductivity, which may cause large polarization and poor rate capability. Hybridization with carbon materials such as graphite, 7,8 carbon nanotubes 9 and graphene 10,11 and reduction of the LVO particle size have been proven to be effective ways to enhance electrical conductivity and abate polarization. For example, carbon-encapsulated LVO nanoparticles synthesized by a simple solid-state method exhibit excellent rate capability and long cycling performance. 1 In addition, defects introduced by doping, thermal treatment at an inert or

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Section: Resultsmentioning

confidence: 99%

Effects of high surface energy on lithium-ion intercalation properties of Ni-doped Li3VO4

et al. 2016

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“…It enables to obtain the dispersion component of the surface energy, adsorption thermodynamic parameters with a wide range of polar substances (specific components of the free energy of adsorption, enthalpy and entropy of adsorption), Lewis acidbase character of the surface, surface nanoroughness parameter, etc. [11][12][13][14]. Thus, using IGC a cellulosic fibrous material can be thoroughly characterized with respect to its surface chemical properties.…”

Section: Page 3 Of 26mentioning

confidence: 99%

Surface properties of distinct nanofibrillated celluloses assessed by inverse gas chromatography

Gamelas

Pedrosa

Lourenço

et al. 2015

Colloids and Surfaces A: Physicochemical and Engineering Aspect

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Surface properties of distinct nanofibrillated celluloses assessed by inverse gas chromatography, Colloids and Surfaces A: Physicochemical and Engineering Aspects (2015), http://dx.doi.org/10.1016/j.colsurfa. 2014.12.058 This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. Higher specific interactions with polar probes were found for enzymatic nanocellulose. The higher values of s d and specific interactions observed for the enzymatic nanocellulose could partly be due to the higher crystallinity of this sample. On the other hand, the increase of the acidity/basicity ratio (as well as of the s d value) for the 15-passes vs. 5-passes TEMPO nanofibres was attributed to a higher exposition of the hydroxyl groups of cellulose at the surface of the former material.

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“…In addition, the surface energy of the mesoporous TiO2 with ALD coating may change, which is another key factor for the loading of QDs. In order to find out the reason, the inverse gas chromatography surface energy analyser (IGC SEA) measurement was adopted to analyze the surface energy of the TiO2 films with and without ALD treatment as SEA is specifically designed to measure surface energy heterogeneity [32,33]. The surface energy can be calculated by the following equation [31]:…”

Section: Resultsmentioning

confidence: 99%

Ultrathin ALD coating on TiO2 photoanodes with enhanced quantum dot loading and charge collection in quantum dots sensitized solar cells

Shen

Tian

2016

Sci. China Mater.

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TiO2 nanocrystals are widely used in photoanodes for quantum dot solar cells (QDSCs) owing to their chemical stability and suitable energy band structure. However, surface defects and grain boundaries of TiO2 nanocrystals photoanodes allow high surface charge recombination, which limits the performance of QDSCs. In this work, an ultrathin TiO2 layer is introduced to the surface of TiO2 photoanodes by atomic layer deposition (ALD). The ultrathin layer not only reduces the surface defects of TiO2 nanoparticles and strengthens the connection between adjacent nanoparticles to suppress the charge recombination for improving the electron collection efficiency (ηcc), but also increases the surface energy of photoanodes to load more quantum dots (QDs) for enhancing the light harvesting efficiency (LHE). As a result, the solar cell based on CdS/CdSe QDs with ALD treatment exhibits an efficiency of 5.07% that is much higher than that of the cells without modification (4.03%).

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An insight into the surface properties of calcined kaolinitic clays: The grinding effect

Cited by 49 publications

References 36 publications

Effects of high surface energy on lithium-ion intercalation properties of Ni-doped Li3VO4

Effects of high surface energy on lithium-ion intercalation properties of Ni-doped Li3VO4

Surface properties of distinct nanofibrillated celluloses assessed by inverse gas chromatography

Ultrathin ALD coating on TiO2 photoanodes with enhanced quantum dot loading and charge collection in quantum dots sensitized solar cells

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