Facile synthesis of novel, known, and low-valent transition metal phosphates <i>via</i> reductive phosphatization

Stegmann, Niklas; Petersen, Hilke; Weidenthaler, Claudia; Schmidt, Wolfgang

doi:10.1039/d1ta03782j

Cited by 5 publications

(29 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both signals correlate with the decomposition of NH 4 + and the release of hydrogen (H 2 ) and ammonia (NH 3 ), as evidenced by the MS data. 26 The XPS data of Ti(IV)p show, in contrast to Ti(III)p, solely Ti in the oxidation state IV+. 26 The H 2 release and the oxidation of Ti 3+ to Ti 4+ imply the redox reaction 2Ti 3+ + 2H + → 2Ti 4+ + H 2 upon heating in inert atmospheres, resulting in the chemical composition Ti IV+ P 2 O 7 for Ti(IV)p.…”

Section: Introductionmentioning

confidence: 99%

“…In a recent publication, we introduced a novel synthesis route for TMPs using metal oxides and NH 4 (H 2 PO 2 ) as a phosphorus source instead of phosphate-based precursors. 26 The specific feature of this synthesis route is the reducing property of NH 4 (H 2 PO 2 ), which stabilizes low-valent transition-metal compounds. With this synthesis route, two novel titanium phosphates with unknown structures could be obtained, hereafter referred to as Ti(III)p and Ti(IV)p. Ti(III)p is formed by annealing the reaction mixture to 573 K. Interestingly, this new phase contains trivalent titanium cations.…”

Section: Introductionmentioning

confidence: 99%

“…With this synthesis route, two novel titanium phosphates with unknown structures could be obtained, hereafter referred to as Ti(III)p and Ti(IV)p. Ti(III)p is formed by annealing the reaction mixture to 573 K. Interestingly, this new phase contains trivalent titanium cations. 26 The combination of the analytical results obtained by energy-dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy (XPS) and analysis of the gaseous decomposition products via thermogravimetric analysis/differential scanning calorimetry coupled with mass spectroscopy (TGA/DSC–MS) result in the chemical composition NH 4 Ti III+ P 2 O 7 . A preliminary discussion of the Raman spectra implies the existence of pyrophosphates [P 2 O 7 ] 4– in the structure.…”

Section: Introductionmentioning

confidence: 99%

“… 26 At elevated temperatures, Ti(III)p reacts to the well-known cubic TiP 2 O 7 structure in air. 26 On the contrary, annealing Ti(III)p in inert atmospheres causes the formation of another yet unknown titanium phosphate structure (Ti(IV)p). 26 In the TGA/DSC–MS experiment, two endothermic signals at ∼723 and ∼762 K are observed during this reaction.…”

Section: Introductionmentioning

confidence: 99%

“… 26 On the contrary, annealing Ti(III)p in inert atmospheres causes the formation of another yet unknown titanium phosphate structure (Ti(IV)p). 26 In the TGA/DSC–MS experiment, two endothermic signals at ∼723 and ∼762 K are observed during this reaction. Both signals correlate with the decomposition of NH 4 + and the release of hydrogen (H 2 ) and ammonia (NH 3 ), as evidenced by the MS data.…”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Crystal Structures of Two Titanium Phosphate-Based Proton Conductors: Ab Initio Structure Solution and Materials Properties

et al. 2021

Self Cite

View full text Add to dashboard Cite

Transition-metal phosphates show a wide range of chemical compositions, variations of the valence states, and crystal structures. They are commercially used as solid-state catalysts, cathode materials in rechargeable batteries, or potential candidates for proton-exchange membranes in fuel cells. Here, we report on the successful ab initio structure determination of two novel titanium pyrophosphates, Ti(III)p and Ti(IV)p, from powder X-ray diffraction (PXRD) data. The low-symmetry space groups P 2 1 / c for Ti(III)p and P 1̅ for Ti(IV)p required the combination of spectroscopic and diffraction techniques for structure determination. In Ti(III)p, trivalent titanium ions occupy the center of TiO 6 polyhedra, coordinated by five pyrophosphate groups, one of them as a bidentate ligand. This secondary coordination causes the formation of one-dimensional six-membered ring channels with a diameter d max of 3.93(2) Å, which is stabilized by NH 4 + ions. Annealing Ti(III)p in inert atmospheres results in the formation of a new compound, denoted as Ti(IV)p. The structure of this compound shows a similar three-dimensional framework consisting of [PO 4 ] 3– tetrahedra and Ti IV+ O 6 octahedra and an empty one-dimensional channel with a diameter d max of 5.07(1) Å. The in situ PXRD of the transformation of Ti(III)p to Ti(IV)p reveals a two-step mechanism, i.e., the decomposition of NH 4 + ions in a first step and subsequent structure relaxation. The specific proton conductivity and activation energy of the proton migration of Ti(III)p, governed by the Grotthus mechanism, belong to the highest and lowest, respectively, ever reported for this class of materials, which reveals its potential application in electrochemical devices like fuel cells and water electrolyzers in the intermediate temperature range.

show abstract

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Crystal Structures of Two Titanium Phosphate-Based Proton Conductors: Ab Initio Structure Solution and Materials Properties

et al. 2021

Self Cite

View full text Add to dashboard Cite

show abstract

Topochemical Synthesis of Copper Phosphide Nanoribbons for Flexible Optoelectronic Memristors

Liu

et al. 2021

Adv Funct Materials

View full text Add to dashboard Cite

Metal phosphide nanoribbons are suitable building blocks for flexible photoelectronic microdevices due to the special electronic structure, large contact area, and excellent mechanical properties. In this work, single‐crystal copper phosphide nanoribbons (Cu3P NRs) are prepared topochemically from crystalline red phosphorus nanoribbons (cRP NRs) to retain the cRP morphology. The Cu3P NRs are used to construct flexible photoelectronic memristors on the ITO/PEN substrate with the native oxidized shell of Cu3P NRs serving as the charge trapping layer to modulate the resistance switching characteristics. The Cu3P NRs‐based memristors have outstanding nonvolatile memory properties in different mechanical bending states and different bending times. Optically and electrically modulated artificial synaptic functions are observed from the Cu3P NRs‐based memristors and owing to the memory backtracking function, pattern recognition is achieved with the Ag/Cu3P/ITO artificial synapse array. The topochemical synthesis method constitutes a universal approach to produce nanostructured compounds with an unusual morphology and specific crystalline orientation. The results also reveal that metal phosphides are excellent materials in memristors for future optoelectronic neuromorphic computing.

show abstract

Electrochemistry of Metal Phosphates and Phosphonates

Silah

Erkmen²,

Uslu³

2023

Engineering Materials

View full text Add to dashboard Cite

Facile synthesis of novel, known, and low-valent transition metal phosphates via reductive phosphatization

Abstract: Novel and known low valent transition metal phosphates (TMPs) are accessible via a novel and facile pathway. The method allows syntheses of TMPs also with reduced oxidation states. The key...

Cited by 5 publications

References 20 publications

Crystal Structures of Two Titanium Phosphate-Based Proton Conductors: Ab Initio Structure Solution and Materials Properties

Crystal Structures of Two Titanium Phosphate-Based Proton Conductors: Ab Initio Structure Solution and Materials Properties

Topochemical Synthesis of Copper Phosphide Nanoribbons for Flexible Optoelectronic Memristors

Electrochemistry of Metal Phosphates and Phosphonates

Contact Info

Product

Resources

About