Search Results

You searched for all publications:

with publication states 'Published (Approved)'
published in journal 'Journal Of Materials Chemistry'

Search Again...

These results only include publications that have been reviewed and processed by Diamond Light Source. To also view papers that have not yet been processed click here.

You can use the folder icon under Actions to collate papers as required. You can then click on View Folder in the left-hand navigation to review and/or download your folder.

Exact matches
Related results

92 items found (0 items not approved), displaying 1 to 10.[First/Prev] 1, 2, 3, 4, 5, 6, 7, 8 [Next/Last]

Instruments / Technical Area	Publication Details	Published
B18-Core EXAFS	What happens structurally and chemically during sodium uptake and release by Ni2P2S6: a combined X-ray diffraction, X-ray absorption, pair distribution function and MAS NMR analysis Wolfgang Bensch , Jonas Van Dinter , Kevin Synnatschke , Tobias Engesser , Sylvio Indris , Niklas Wolff , Ole Gronenberg , Martin Etter , Giannantonio Cibin , Lorenz Kienle , Claudia Backes Journal Of Materials Chemistry A DOI: 10.1039/D0TA07889A Diamond Proposal Number(s): [20060] Show Abstract ▼ Abstract: The layered compound Ni2P2S6 was electrochemically characterized for application as anode material in sodium-ion batteries (SIBs). A high reversible capacity of 621 mAh g 1 at 1 A g 1 was achieved after 190 cycles. The investigation of the complex reaction mechanism of the conversion reaction was performed applying complementary techniques including X-ray powder diffraction, pair distribution function analyses, X-ray absorption spectroscopy, 19F/23Na/31P MAS NMR, TEM and nano-EDX. The results highlight that Na uptake for up to 5 Na/formula unit (f.u.) led to reduction of Ni2+ to metallic Ni nanoparticles and concomitant formation of an intermediate compound Na4P2S6. Increasing the Na content to 12 Na/f.u. generates nanocrystalline Na2S, which is accompanied by loss of the long-range order of the pristine sample. In the completely discharged state elemental Ni and Na2S are present, but in contrast to literature reports, no evidence for the formation of NaxP phases was found. During the charge process, Ni3S2 is formed upon the release of ~11.7 Na/f.u. A very high specific capacity of 621 mAh g 1 at 1.0 A g 1 is obtained after 190 cycles, and Coulombic efficiencies reach nearly 100% after the 3rd cycle.	Oct 2020
B18-Core EXAFS	Lithiation of V2O3 (SO4)2 – a flexible insertion host Stephanie F. Linnell , Julia L. Payne , David M. Pickup , Alan V. Chadwick , A. Robert Armstrong , John T. S. Irvine Journal Of Materials Chemistry A 104 DOI: 10.1039/D0TA06608G Diamond Proposal Number(s): [14239] Open Access Show Abstract ▼ Abstract: Materials that display strong capabilities for lithium insertion without significant change in unit cell size on cycling are of considerable importance for electrochemical applications. Here, we present V2O3(SO4)2 as a host for lithium-ion batteries. Electrochemically, 2.0 Li+ ions can be inserted, giving Li2V2O3(SO4)2 with an oxidation state of V4+, as determined by X-ray absorption spectroscopy. The capacity of V2O3(SO4)2 can be increased from 157 mA h g−1 to 313 mA h g−1 with the insertion of two additional Li+ ions which would drastically improve the energy density of this material, but this would be over a wider potential range. Chemical lithiation using n-butyllithium was performed and characterisation using a range of techniques showed that a composition of Li4V2O3(SO4)2 can be obtained with an oxidation state of V3+. Structural studies of the lithiated materials by X-ray diffraction showed that up to 4.0 Li+ ions can be inserted into V2O3(SO4)2 whilst maintaining its framework structure.	Sep 2020
B18-Core EXAFS I11-High Resolution Powder Diffraction	Na2Fe2OS2, a new earth abundant oxysulphide cathode material for Na-ion batteries Jacinthe Gamon , Arnaud J. Perez , Leanne A. H. Jones , Marco Zanella , Luke M. Daniels , Rhun E. Morris , Chiu C. Tang , Tim Veal , Laurence J. Hardwick , Matthew S Dyer , John B. Claridge , Matthew J. Rosseinsky Journal Of Materials Chemistry A DOI: 10.1039/D0TA07966A Open Access Show Abstract ▼ Abstract: Multiple anion materials are of particular interest for the discovery of new crystal structures and offer an original way to modulate physical properties, including energy storage materials with enhanced performances. Through careful synthesis optimization, a new Na2Fe2OS2 phase was prepared by two different routes: high temperature solid-state synthesis and simple mechanochemical synthesis. The long-range and local structure of Na2Fe2OS2 was studied by Rietveld refinement of neutron and X-ray diffraction data combined with EXAFS data refinement. The phase comprises an amorphous and a crystalline part which has an anti-K2NiF4 structure, corresponding to the n = 1 member of the homologous anti-Ruddlesden-Popper [AX][ABX3]n series. Its electrochemical properties as a cathode material were studied in Na half cells and Na-ion full cells, revealing that the material becomes fully amorphous upon initial desodiation to Na0.5Fe2OS2, but maintains a reversible capacity of 135 mAh·g-1 in full cells where up to 1.2 Na+ can be reversibly extracted and reinserted when compensating for the Na lost in SEI formation. The stability of the pristine material and its structural evolution upon charging are discussed, paving the way for further optimization of this material. Being composed exclusively of earth-abundant elements and stable under dry air, Na2Fe2OS2 perfectly illustrates the great opportunity of multiple anion chemistry to explore new structure types and develop better energy storage systems.	Sep 2020
I15-1-X-ray Pair Distribution Function (XPDF)	Pyrochlore nanocrystals as versatile quasi-single-source precursors to lithium conducting garnets J. Mark Weller , Candace Chan Journal Of Materials Chemistry A 43 DOI: 10.1039/D0TA05842D Diamond Proposal Number(s): [23152] Open Access Show Abstract ▼ Abstract: Lithium conducting garnets are attractive solid electrolytes for solid-state lithium batteries but are difficult to process, generally requiring high reaction and sintering temperatures with long durations. In this work, we demonstrate a synthetic route to obtain Ta-doped garnet (Li6.4La3Zr1.4Ta0.6O12) utilizing La- and Ta-doped lanthanum zirconate (La2.4Zr1.12Ta0.48O7.04) pyrochlore nanocrystals as quasi-single-source precursors. Via molten salt synthesis (MSS) in a highly basic flux, the pyrochlore nanocrystals transform to Li-garnet at reaction temperatures as low as 400 °C. We also show that the pyrochlore-to-garnet conversion can take place in one step using reactive sintering, resulting in densified garnet ceramics with high ionic conductivity (0.53 mS cm−1 at 21 °C) and relative density (up to 94.7%). This approach opens new avenues for lower temperature synthesis of lithium garnets using a quasi-single-source precursor and provides an alternative route to highly dense garnet solid electrolytes without requiring advanced sintering processes.	Aug 2020
I09-Surface and Interface Structural Analysis	Sb 5s2 lone pairs and band alignment of Sb2Se3 : a photoemission and density functional theory study Christopher H. Don , Huw Shiel , Theodore D. C. Hobson , Christopher N. Savory , Jack E. N. Swallow , Matthew J. Smiles , Leanne A. H. Jones , Thomas J. Featherstone , Pardeep K. Thakur , Tien-lin Lee , Ken Durose , Jonathan D. Major , Vinod R. Dhanak , David O. Scanlon , Tim D. Veal Journal Of Materials Chemistry C 27 DOI: 10.1039/D0TC03470C Diamond Proposal Number(s): [21431] Open Access Show Abstract ▼ Abstract: The presence of a lone pair of 5s electrons at the valence band maximum (VBM) of Sb2Se3 and the resulting band alignments are investigated using soft and hard X-ray photoemission spectroscopy in parallel with density functional theory (DFT) calculations. Vacuum-cleaved and exfoliated bulk crystals of Sb2Se3 are analysed using laboratory and synchrotron X-ray sources to acquire high resolution valence band spectra with both soft and hard X-rays. Utilising the photon-energy dependence of different orbital cross-sections and corresponding DFT calculations, the various orbital contributions to the valence band could be identified, including the 5s orbital's presence at the VBM. The ionization potential is also determined and places the VBM at 5.13 eV below the vacuum level, similar to other materials with 5s2 lone pairs, but far above those of related materials without lone pairs of electrons.	Aug 2020
B18-Core EXAFS I20-Scanning-X-ray spectroscopy (XAS/XES)	Nickel confined in 2D earth-abundant oxide layers for highly efficient and durable oxygen evolution catalysts Yayun Pu , Matthew J. Lawrence , Veronica Celorrio , Qi Wang , Meng Gu , Zongzhao Sun , Leonardo Agudo Jácome , Andrea E. Russell , Limin Huang , Paramaconi Rodriguez Journal Of Materials Chemistry A 8, 13340 - 13350 DOI: 10.1039/D0TA04031B Diamond Proposal Number(s): [19850, 21659] Open Access Show Abstract ▼ Abstract: Low cost, high-efficiency catalysts towards water splitting are urgently required to fulfil the increasing demand for energy. In this work, low-loading (<20 wt%) Ni-confined in layered metal oxide anode catalysts (birnessite and lepidocrocite titanate) have been synthesized by facile ion exchange methodology and subjected to systematic electrochemical studies. It was found that Ni-intercalated on K-rich birnessite (Ni-KMO) presents an onset overpotential (ηonset) as low as 100 mV and overpotential at 10 mA cm−2 (η10) of 206 mV in pH = 14 electrolyte. By combining electrochemical methods and X-ray absorption and emission spectroscopies (XAS and XES), we demonstrate Ni sites are the active sites for OER catalysis and that the Mn3+ sites facilitate Ni intercalation during the ion-exchange process, but display no observable contribution towards OER activity. The effect of the pH and the nature of the supporting electrolyte on the electrochemical performance was also evaluated.	Jul 2020
B18-Core EXAFS E01-JEM ARM 200CF E02-JEM ARM 300CF	Pt single-atoms supported on nitrogen-doped carbon dots for highly efficient photocatalytic hydrogen generation Hui Luo , Ying Liu , Stoichko D. Dimitrov , Ludmilla Steier , Shaohui Guo , Xuanhua Li , Jingyu Feng , Fei Xie , Yuanxing Fang , Andrei Sapelkin , Xinchen Wang , Maria-magdalena Titirici Journal Of Materials Chemistry A 48 DOI: 10.1039/D0TA04431H Diamond Proposal Number(s): [22447, 20116] Show Abstract ▼ Abstract: Single-atom catalysis has become the most active new frontier in energy conversion applications due to its remarkable catalytic activity and low material consumption. However, the issue of atom aggregation during the synthesis process or catalytic reaction must be overcome. In this work, we have developed a one-step photo-deposition process to fabricate Pt single-atom catalysts (SACs) on nitrogen doped carbon dots (NCDs). The Pt–NCDs were then hybridized with TiO2 to achieve high hydrogen generation activity and to understand the fundamentals at the Pt/NCD/TiO2 interface. The synergistic effect of Pt SAC and NCDs with maximized atomic efficiency of Pt and improved charge transfer capability provides a new strategy to rationally design a multi-scale photocatalyst structure to achieve high H2 evolution efficiency. The facile synthesis process also holds great potential for various applications such as electrocatalysis, heterogeneous catalysis and drug delivery, providing a promising way to reduce the high cost of noble metals.	Jul 2020
B18-Core EXAFS	Solvothermal synthesis of Sn3N4 as a high capacity sodium-ion anode: theoretical and experimental study of its storage mechanism Samuel D. S. Fitch , Giannantonio Cibin , Steven P. Hepplestone , Nuria Garcia-araez , Andrew L. Hector Journal Of Materials Chemistry A 3 DOI: 10.1039/D0TA04034G Diamond Proposal Number(s): [14239] Open Access Show Abstract ▼ Abstract: A new simple and scalable method to synthesise spinel-structured Sn3N4 has been developed using SnCl4 and LiNH2 precursors under solvothermal conditions. Nanocrystalline Sn3N4 with a crystallite size < 10 nm was produced and tested as anode material in sodium half cells, demonstrating a very high reversible (de-sodiation) capacity of ∼850 mA h g−1 measured over 50 cycles, the highest reported reversible capacity for a sodium anode apart from sodium itself. Ex situ X-ray absorption spectroscopy and X-ray diffraction show that the electrochemical reactions are reversible and that Sn3N4 is recovered upon re-oxidation. X-ray diffraction shows that the peaks associated with Sn3N4 reflections become narrower during discharge (reduction), evidencing that the smaller Sn3N4 particles are primarily involved in the electrochemical reactions, and broadening of the peaks is reversibly recovered upon oxidation. The analysis of the near edge X-ray absorption data (XANES) shows that the Sn oxidation state decreases during reduction and nearly recovers the initial value during oxidation. DFT calculations suggest that the insertion of Na into the Sn3N4 surface followed by substitution of tetrahedral Sn by Na is energetically favourable, and evidence of the removal of tetrahedral Sn from the spinel Sn3N4 structure is obtained from the analysis of the extended X-ray absorption fine-structure (EXAFS) measurements of reduced electrodes, which also show the recovery of the pristine structure at the end of oxidation. DFT also shows that Sn substitution by Na is only favourable at the Sn3N4 surface (not for bulk Sn3N4), in agreement with the electrochemical characterisation that shows that controlling the nanoparticle size is crucial to achieve full utilisation of Sn3N4 (and thus high capacity).	Jul 2020
I22-Small angle scattering & Diffraction	Solvent vapour annealing of methylammonium lead halide perovskite: what's the catch? Onkar S. Game , Joel A. Smith , Tarek I. Alanazi , Michael Wong-stringer , Vikas Kumar , Cornelia Rodenburg , Nick J. Terrill , David Lidzey Journal Of Materials Chemistry A 8, 10943 - 10956 DOI: 10.1039/D0TA03023F Diamond Proposal Number(s): [18563] Show Abstract ▼ Abstract: Solvent vapour annealing (SVA) is a common post-processing technique used to increase the average grain size of lead halide perovskite films and thus enhance device performance. The prevailing wisdom is that large grain perovskite films lead to enhanced stability, however, we observed the reverse in CH3NH3PbI3 (MAPbI3) with dimethylformamide vapour treatment compared to non-SVA controls. Using a range of microstructural characterisation techniques, we reveal that SVA is not a chemically benign grain-growth process, but leads to substantial stoichiometric changes in the perovskite films. Intrinsic material degradation is investigated under external loading with in situ X-ray scattering, and combined with lifetime testing on full devices. We show that the operational stability of SVA devices greatly depends on the initial stoichiometry of the MAPbI3 with PbI2-excess compositions being least stable. However, the incorporation of excess organic-halides in the precursor solution helps to mitigate the deleterious effects of SVA on device stability. This work critically re-evaluates current thinking around grain structure and stoichiometry in achieving long-term stability for perovskite solar cells.	Jun 2020
I16-Materials and Magnetism I22-Small angle scattering & Diffraction	Tailoring liquid crystal honeycombs by head-group choice in bird-like bent-core mesogens Ya-xin Li , Huifang Cheng , Xiangbing Zeng , Yuan Tao , Xiaohong Cheng , Goran Ungar Journal Of Materials Chemistry C 106 DOI: 10.1039/D0TC01879A Open Access Show Abstract ▼ Abstract: We introduce a new class of mesogens that are bird-like in shape and form honeycomb-type supramolecular liquid crystals. They have a bent pi-conjugated aromatic core as wings, a linear or branched chain as the tail and a selection of functional headgroups. Honeycombs of non-centrosymmetric trigonal type (p3m1) are obtained, along with two different complex honeycomb superlattices (p31m and p2gg) and a randomized hexagonal mesophase (p6mm). The key determinant of the self-assembled structure is the nature of interaction of the headgroup with the glycerols at the ends of the wings. The structure depends on whether the sub-columns lying along the edges of the prismatic cells contain pure or mixed headgroups and wing-end hydrogen-bonding groups. Its assembly is further controlled by reducing the tail-chain volume, inducing out-of-plane buckling of the honeycomb. These two modes of symmetry breaking lead to structural polarity both in- and out-of-plane, opening the way to applications in devices relying on properties such as ferroelectricity and second harmonic generation.	May 2020

Publications Database

Search Results

You searched for all publications:

Search Again...

Subject Areas (check all that apply) select all

Instruments used to collect data (check all that apply) select all

Collaborations involved (check all that apply) select all

Diamond Offline Facilities used

Relevant Technical Areas (check all that apply) select all

Menu for Anonymous User