Search Results

You searched for all publications:

with publication states 'Published (Approved)'

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

3 items found (0 items not approved), displaying all items.1

Instruments / Technical Area	Publication Details	Published
I15-1-X-ray Pair Distribution Function (XPDF)	Monitoring the structure evolution of titanium oxide photocatalysts: From the molecular form via the amorphous state to the crystalline phase Ezgi Onur Sahin , Yitao Dai , Candace Chan , Harun Tuysuz , Wolfgang Schmidt , Joohyun Lim , Siyuan Zhang , Cristina Scheu , Claudia Weidenthaler Chemistry – A European Journal DOI: 10.1002/chem.202101117 Diamond Proposal Number(s): [12102] Show Abstract ▼ Abstract: Amorphous TixOy with high surface area has attracted significant interest as photocatalyst with higher activity in ultraviolet (UV) light-induced water splitting applications compared to commercial nanocrystalline TiO2. Under photocatalytic operation conditions, the structure of the molecular titanium alkoxide precursor rearranges upon hydrolysis and leads to higher connectivity of the structure-building units. Structurally ordered domains with sizes smaller than 7 Å form larger aggregates. The experimental scattering data can be explained best with a structure model consisting of an anatase-like core and a distorted shell. Upon exposure with UV light, the white TixOy suspension turns dark corresponding to the reduction of Ti 4+ to Ti 3+ as confirmed by electron energy loss spectroscopy (EELS). Heat-induced crystallisation was followed by in situ temperature-dependent total scattering experiments. First, ordering in the Ti-O environment takes place upon to 350 °C. Above this temperature, the distorted anatase core starts to grow but the structure obtained at 400 °C is still not fully ordered.	Jun 2021
I15-1-X-ray Pair Distribution Function (XPDF)	In situ total scattering experiments of nucleation and crystallisation of tantalum-based oxides: from highly dilute solutions via cluster formation to nanoparticles Ezgi Onur Sahin , Harun Tueysuez , Candace K. Chan , Gun-Hee Moon , Yitao Dai , Wolfgang Schmidt , Joohun Lim , Christina Scheu , Claudia Weidenthaler Nanoscale DOI: 10.1039/D0NR07871A Diamond Proposal Number(s): [16372] Open Access Show Abstract ▼ Abstract: The exact formation mechanism of tantalum oxides (and in general, metal/mixed metal oxides) from alkoxide precursors is still not fully understood, particularly when forming cluster-like or amorphous materials. The structural evolution of Ta-based oxides was studied in detail using X-ray total scattering experiments along with subsequent pair distribution function (PDF) analyses. Starting from a tantalum alkoxide precursor (Ta2(OEt)10), the formation of hydrolysed TaxOyHz clusters in highly diluted aqueous solution was analysed. From the PDF data, the connectivity and arrangement of TaxOy octahedra in the cluster could be deduced as well as the approximate size of the clusters (<1 nm). Construction of cluster models allowed for identification of common structural motifs in the TaxOyHz clusters, ruling out the formation of chain- or ring-like clusters. More likely, bulky clusters with a high number of corner-sharing octahedra are formed. After separation of the amorphous solid from the liquid, temperature-induced crystallisation processes were monitored via in situ total scattering experiments. Between room temperature and 600 °C, only small rearrangements of the amorphous structure are observed. At about 610 °C, amorphous TaxOyHz transforms directly into crystalline orthorhombic L-Ta2O5 without formation of any crystalline intermediate structures.	Nov 2020
I20-Scanning-X-ray spectroscopy (XAS/XES)	Tailoring morphology and electronic structure of cobalt iron oxide nanowires for electrochemical oxygen evolution reaction Eko Budiyanto , Mingquan Yu , Minmin Chen , Serena Debeer , Olaf Rudiger , Harun Tuysuz Acs Applied Energy Materials DOI: 10.1021/acsaem.0c01201 Diamond Proposal Number(s): [21526] Open Access Show Abstract ▼ Abstract: Herein, the influence of iron on nanocasting of cobalt oxide nanowires and the performance of these materials for the oxygen evolution reaction (OER) are investigated. Pristine Co3O4 and mixed cobalt iron oxide nanowires with a diameter of 7 nm have been synthesized via a nanocasting route by using SBA 15 silica as a template. A small amount of iron added during the synthesis results in a decrease in the nanowires’ array length and induces the formation of a bimodal pore size distribution. Raman Spectroscopy, X-ray emission and high-energy resolution X-ray absorption spectroscopies further show that Fe incorporation alters the electronic structure by increasing the average distortion around the cobalt centers and the amount of Co2+ in tetrahedral sites. These affect the OER activity significantly; the overpotential of pristine Co3O4 at 10 mA/cm2 decreases from 398 to 378 mV, and the current density at 1.7 V increases from 107 to 150 mA/cm2 with the addition of iron at Co/Fe atomic ratio of 32. Furthermore, post-reaction characterization confirmed that both the morphology and electronic structure of nanowires remain intact after a long-term stability test.	Aug 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