Vibrational spectra and thermal dehydration of Co2P2O7·6H2O diphosphate

Harcharras, Mohamed; Ennaciri, A.; Capitelli, Francesco; Mattei, Giorgio

doi:10.1016/j.vibspec.2003.09.001

Cited by 32 publications

(19 citation statements)

References 25 publications

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“…The Fig. shows the FT‐IR spectrum of Sr 2 P 2 O 7 hydrated sample, which closely resembles to those of X 2 P 2 O 7 (X = Cu, Ca, Cd, Fe, Mn) . From the spectrum, it is observed that the narrow absorption bands occurring at 3588.6/cm and 1629.9/cm are due to the O–H stretching and O–H in‐plane bending vibration, respectively, due to the moisture content or water of hydration.…”

Section: Resultsmentioning

confidence: 67%

Synthesis, Crystal Structure, Spectroscopic and Thermal Analysis of Strontium Pyrophosphate Dihydrate Nanoparticles

Solanki

Vasant

Joshi

2014

Int J Applied Ceramic Tech

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Various pyrophosphates are very useful as bioceramics; for instance, strontium pyrophosphate is one of the emerging forms of alkaline phosphate. Strontium pyrophosphate dihydrate (Sr 2 P 2 O 7 2H 2 O) nanoparticles were synthesized by the surfactant-mediated approach and characterized by different techniques. From the powder XRD study, the average crystallite size was evaluated by applying Scherrer's formula, which was found to be 33.57 nm. The average crystallite size and internal strain were also evaluated using Williamson-Hall (W-H) method. The FT-IR spectroscopy study confirmed the presence of symmetric and asymmetric stretching vibrations of P-O-P and PO 3 . The UV-NIR absorption spectroscopy over the spectral range of 210-1200 nm was employed, and the energy band gap was calculated from Tauc's plot which was found to be 4.9 eV. Thermogravimetric analysis (TGA) confirmed the presence of two water molecules in the sample. From TGA, it was found that the sample become anhydrous and on heating above 410-800°C, the sample remained almost stable with slight weight gain due to adsorption of purged gas. Various kinetic parameters and thermodynamic parameters were evaluated for dehydration process. *pds_2307@yahoo.co.in

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Section: Resultsmentioning

confidence: 67%

Synthesis, Crystal Structure, Spectroscopic and Thermal Analysis of Strontium Pyrophosphate Dihydrate Nanoparticles

Solanki

Vasant

Joshi

2014

Int J Applied Ceramic Tech

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“…Despite the significant interest for synthetic whitlockite that has emerged during the last years in biomaterial sciences [46], a complete FTIR study of natural whitlockite is missing in the literature. We can, thus, use for comparison the data known for the spectrum of the isotypical β-TCP, which has been widely investigated in terms of site-symmetry and factor group analysis [47,48], see also [39,40,49]. According to [47,48,50], the free phosphate ion (PO 4 ) 3− with ideal T d point symmetry displays four vibrational modes: (1) the antisymmetric stretching ν 3 at 1082 cm −1 ; (2) the symmetric stretching ν 1 at 980 cm −1 ;…”

Section: Ftir Spectroscopymentioning

confidence: 99%

Neutron and XRD Single-Crystal Diffraction Study and Vibrational Properties of Whitlockite, the Natural Counterpart of Synthetic Tricalcium Phosphate

et al. 2021

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A crystal chemical investigation of a natural specimen of whitlockite, ideally Ca9Mg(PO4)6[PO3(OH)], from Palermo Mine (USA), was achieved by means of a combination of electron microprobe analysis (EMPA) in WDS mode, single-crystal neutron diffraction probe (NDP) and single-crystal X-ray diffraction (XRD), and Fourier transform infrared (FTIR) spectroscopy. The crystal-chemical characterization resulted in the empirical formula (Ca8.682Na0.274Sr0.045)Σ9.000(Ca0.034□0.996)Σ1.000(Mg0.533Fe2+0.342Mn2+0.062Al0.046)Σ0.983(P1.006O4)6[PO3(OH0.968F0.032)Σ1.000]. Crystal-structure refinement, in the space group R3c, converged to R1 = 7.12% using 3273 unique reflections from NDP data and to R1 = 2.43% using 2687 unique reflections from XRD data. Unit cell parameters from NDP are a = 10.357(3) Å, c = 37.095(15) Å and V = 3446(2) Å3, and from XRD, the parameters are a = 10.3685(4) Å, c = 37.1444(13) Å and V = 3458.2(3) Å3. NDP results allowed a deeper definition of the hydrogen-bond system and its relation with the structural unit [PO3(OH)]. The FTIR spectrum is very similar to that of synthetic tricalcium phosphate Ca3(PO4)2 and displays minor band shifts due to slightly different P-O bond lengths and to the presence of additional elements in the structure. A comparison between whitlockite, isotypic phases from the largest merrillite group, and its synthetic counterpart Ca3(PO4)2 is provided, based on the XRD/NDP and FTIR results.

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“…The strong symmetric vibrations of PO 3 group and POP bridge are observed in Raman spectrum at 1030 and 740 cm −1 , respec tively, further confirming the existence of pyrophosphate group in CoPPi nanowires ( Figure S2, Supporting Information). [23] Xray diffraction (XRD) pattern of the product illustrates four predominate peaks located at 24.6°, 29.2°, 30.4°, and 36.2° ( Figure S3, Supporting Information), which can be assigned to (120), (111), (12), and (040) planes of Co 2 P 2 O 7 (JCPDS No. 870457), respectively.…”

Section: Doi: 101002/smll201801068mentioning

confidence: 99%

Engineering Morphologies of Cobalt Pyrophosphates Nanostructures toward Greatly Enhanced Electrocatalytic Performance of Oxygen Evolution Reaction

Zhao

et al. 2018

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Herein, a surfactant- and additive-free strategy is developed for morphology-controllable synthesis of cobalt pyrophosphate (CoPPi) nanostructures by tuning the concentration and ratio of the precursor solutions of Na P O and Co(CH COO) . A series of CoPPi nanostructures including nanowires, nanobelts, nanoleaves, and nanorhombuses are prepared and exhibit very promising electrocatalytic properties toward the oxygen evolution reaction (OER). Acting as both reactant and pseudo-surfactant, the existence of excess Na P O is essential to synthesize CoPPi nanostructures for unique morphologies. Among all CoPPi nanostructures, the CoPPi nanowires catalyst renders the best catalytic performance for OER in alkaline media, achieving a low Tafel slope of 54.1 mV dec , a small overpotential of 359 mV at 10 mA cm , and superior stability. The electrocatalytic activities of CoPPi nanowires outperform the most reported non-noble metal based catalysts, even better than the benchmark Ir/C (20%) catalyst. The reported synthesis of CoPPi gives guidance for morphology control of transition metal pyrophosphate based nanostructures for a high-performance inexpensive material to replace the noble metal-based OER catalysts.

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Vibrational spectra and thermal dehydration of Co2P2O7·6H2O diphosphate

Cited by 32 publications

References 25 publications

Synthesis, Crystal Structure, Spectroscopic and Thermal Analysis of Strontium Pyrophosphate Dihydrate Nanoparticles

Synthesis, Crystal Structure, Spectroscopic and Thermal Analysis of Strontium Pyrophosphate Dihydrate Nanoparticles

Neutron and XRD Single-Crystal Diffraction Study and Vibrational Properties of Whitlockite, the Natural Counterpart of Synthetic Tricalcium Phosphate

Engineering Morphologies of Cobalt Pyrophosphates Nanostructures toward Greatly Enhanced Electrocatalytic Performance of Oxygen Evolution Reaction

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