Synthesis and structural characterisation of solid titanium(iv) phosphate materials by means of X-ray absorption and NMR spectroscopyShow others and affiliations
2022 (English)In: Dalton Transactions, ISSN 1477-9226, E-ISSN 1477-9234, Vol. 51, no 21, p. 8192-8207Article in journal (Refereed) Published
Abstract [en]
Solid titanium phosphate, TiP, materials hold great promise for wastewater treatment for removal of metal ions and complexes. A series of TiP materials, synthesised at mild conditions and short reaction times, have been structurally characterised using solid-state X-ray absorption spectroscopy, phosphorus and titanium K edge XANES and EXAFS, and 31P and 47/49Ti NMR spectroscopy. The titanium K edge EXAFS data of α-Ti(HPO4)2·H2O (α-TiP) revealed octahedral coordination of oxygens around titanium. Repeated washing of primary β-/γ-TiP with hydrochloric acid results in formation of a weakly ordered solid, TiO(OH)(H2PO4)·H2O, TiP1-H. The structure of TiP1-H is shown by Ti EXAFS to be a titanyl compound, containing a short Ti O bond. The analogous data for linked titanium phosphate compounds (LTP) disclosed that inter-linkage occurs between α-TiP and titanyl phosphate units, supported by 31P-31P NOESY NMR data. 47/49Ti NMR and Ti pre-edge XANES show evidence of two different titanium environments in LTP, one very similar to that observed in TiP1-H and a second more symmetric octahedral environment. Data are discussed in terms of induced acidic hydrolyses of titanium(iv) and phosphate counterpart during washings with hydrochloric acid and water. A straightforward relation between synthesis parameters/post synthetic treatment and structural re-arrangement in the materials is established.
Place, publisher, year, edition, pages
Royal Society of Chemistry , 2022. Vol. 51, no 21, p. 8192-8207
Keywords [en]
Chemicals removal (water treatment), Metals, Nuclear magnetic resonance spectroscopy, Washing, Wastewater treatment, X ray absorption spectroscopy, Condition, EXAFS, Metals ions, NMR-spectroscopy, Removal of metals, Structural characterization, Synthesised, Titania, X-ray absorption spectroscopy, XANES, Metal ions
National Category
Chemical Engineering
Identifiers
URN: urn:nbn:se:ri:diva-59845DOI: 10.1039/d2dt00902aScopus ID: 2-s2.0-85132007265OAI: oai:DiVA.org:ri-59845DiVA, id: diva2:1685337
Note
Funding details: Engineering and Physical Sciences Research Council, EPSRC; Funding details: Biotechnology and Biological Sciences Research Council, BBSRC, EP/T015063/1; Funding details: University of Warwick; Funding details: Svenska Forskningsrådet Formas; Funding details: Luleå Tekniska Universitet, LTU; Funding details: European Regional Development Fund, ERDF; Funding details: Synchrotron Light Research Institute, SLRI; Funding text 1: The UK High-Field Solid-State NMR Facility used in this research was funded by EPSRC and BBSRC (EP/T015063/1), as well as the University of Warwick including via part funding through Birmingham Science City Advanced Materials Projects 1 and 2 supported by Advantage West Midlands (AWM) and the European Regional Development Fund (ERDF). We acknowledge the Swedish Research Council for Environmental, Agricultural Science and Spatial Planning (Formas) for financial support. The NMR equipment at Luleå University of Technology (LTU) is financed by grants from the Foundation in memory of J. C. and Seth M. Kempe, and the LTU laboratory fund. The travelling grant from the Wallenberg Foundation (Sweden) to MT is gratefully acknowledged. We thank Dr. Vasantha Gowda for assistance in the analysis of pXRD patterns of TiP compounds with reported single crystal structures. The Synchrotron Light Research Institute (SLRI), Nakhon Ratchasima, Thailand, is acknowledged for allocation of beam-time and laboratory facilities.
2022-08-022022-08-022022-08-09Bibliographically approved