A5055146293- Zeolite Catalysis and Synthesis
- Mesoporous Materials and Catalysis
- Catalytic Processes in Materials Science
- Metal-Organic Frameworks: Synthesis and Applications
- Catalysis and Oxidation Reactions
- Chemical Synthesis and Characterization
- Advanced Chemical Physics Studies
- Advanced Photocatalysis Techniques
- High-pressure geophysics and materials
- X-ray Diffraction in Crystallography
- Crystal Structures and Properties
- Electrocatalysts for Energy Conversion
- Advancements in Battery Materials
- Magnetic and transport properties of perovskites and related materials
- Electronic and Structural Properties of Oxides
- Crystallization and Solubility Studies
- 2D Materials and Applications
- Graphene research and applications
- Advanced Thermoelectric Materials and Devices
- Inorganic Fluorides and Related Compounds
- Diamond and Carbon-based Materials Research
- Solid-state spectroscopy and crystallography
- Inorganic Chemistry and Materials
- Transition Metal Oxide Nanomaterials
- Advanced Battery Materials and Technologies
University College London
2015-2024
Thomas Young Centre
2009-2023
University College Lahore
2020-2021
Transnational Press London
2017-2020
BuroHappold (United Kingdom)
2017-2018
Christ University
2017-2018
Royal Institution of Great Britain
2000-2012
Instituto de Catálisis y Petroleoquímica
2004-2010
University of the Basque Country
2007-2010
The University of Tokyo
2008
Graphitic carbon nitride compounds were prepared by thermal treatment of C–N–H precursor mixtures (melamine C3N6H9, dicyandiamide C2N4H4). This led to solids based on polymerized heptazine or triazine ring units linked −N═ −NH– groups. The H content decreased, and the C/N ratio varied between 0.59 0.70 with preparation temperatures 550 650 °C due increased layer condensation. UV–vis spectra exhibited a strong π–π* transition near 400 nm semiconductor-like band edge extending into visible...
Carbon nitride compounds with high N : C ratios and graphitic to polymeric structures are being investigated as potential next-generation materials for incorporation in devices energy conversion storage well optoelectronic catalysis applications. The built from C- N-containing heterocycles heptazine or triazine rings linked via sp2-bonded atoms (N(C)3 units) -NH- groups. electronic, chemical optical functionalities determined by the nature of local extended composition materials. Because...
The structure and electronic properties of single-layered carbon nitride graphenes are examined computationally with hybrid-exchange functionals in periodic density functional theory calculations. Unlike pure graphene that provides a metallic nanomaterial, form semiconductors band gaps ranging up to 5 eV. gap is sensitive external perturbations can be introduced chemically by adatom adsorption or physically constraining the lattice parameter. Carbon could possibly pave way for new range...
Abstract Cost‐effective and environment‐friendly aqueous zinc‐ion batteries (AZIBs) exhibit tremendous potential for application in grid‐scale energy storage systems but are limited by suitable cathode materials. Hydrated vanadium bronzes have gained significant attention AZIBs can be produced with a range of different pre‐intercalated ions, allowing their properties to optimized. However, gaining detailed understanding the mechanisms within these materials remains great challenge due...
A detrimental competition between the urea oxidation reaction (UOR) and oxygen evolution is identified. Strategies are proposed to alleviate such boost performance of UOR other organic compound reactions.
Blocking heat in two ways Low thermal conductivity is important for barrier coatings, thermoelectrics, and other applications. Gibson et al . combined complementary methods that manipulate internal interface properties to dramatically decrease the of inorganic material BiO 2 Cl Se (see Perspective by Kim Cahill). The authors took advantage both in-plane structural distortions weak bonding layers push down 0.1 watts per kelvin meter: only four times air. principles should be applicable...
Abstract The heavy reliance of lithium-ion batteries (LIBs) has caused rising concerns on the sustainability lithium and transition metal ethic issue around mining practice. Developing alternative energy storage technologies beyond become a prominent slice global research portfolio. play vital role in shaping future landscape storage, from electrified mobility to efficient utilization renewable energies further large-scale stationary storage. Potassium-ion (PIBs) are promising given its...
Breathtaking MOFs: DFT calculations reveal that the exceptional, thermally induced density change of metal–organic framework MIL53(Al) is controlled by a competition between short- and long-range interactions entropic factors. As shown in picture (C green, Al cyan, O red, H white), dispersive phenyl rings are responsible for stabilizing narrow-pore form at low temperature. At 325–375 K, vibrational entropy causes structure to expand markedly, permitting large volumes light gases be adsorbed....
Abstract The synthesis of metal–organic frameworks with large three‐dimensional channels that are permanently porous and chemically stable offers new opportunities in areas such as catalysis separation. Two linkers (L1=4,4′,4′′,4′′′‐([1,1′‐biphenyl]‐3,3′,5,5′‐tetrayltetrakis(ethyne‐2,1‐diyl)) tetrabenzoic acid, L2=4,4′,4′′,4′′′‐(pyrene‐1,3,6,8‐tetrayltetrakis(ethyne‐2,1‐diyl))tetrabenzoic acid) were used have equivalent connectivity dimensions but quite distinct torsional flexibility. With...
The first study on relationship between the cation pre-intercalation amount in MnO<sub>2</sub> matrix and electrochemical performances of AZIBs are provided.
Electrochemical power sources, such as polymer electrolyte membrane fuel cells (PEMFCs), require the use of precious metal catalysts which are deposited nanoparticles onto supports in order to minimize their mass loading and therefore cost. State-of-the-art/commercial based on forms carbon black. However, present disadvantages including corrosion operating cell environment loss catalyst activity. Here we review recent work examining potential different varieties graphitic nitride (gCN)...
Abstract The hydrogen evolution reaction (HER) is a critical process in the electrolysis of water. Recently, much effort has been dedicated to developing low‐cost, highly efficient, and stable electrocatalysts. Transition metal phosphides are investigated intensively due their high electronic conductivity optimized absorption energy intermediates acid electrolytes. However, low stability phosphide materials air during electrocatalytic processes causes decay performance hinders discovery...
The search for new nanostructural topologies composed of elemental carbon is driven by technological opportunities as well the need to understand structure and evolution materials formed planetary shock impact events in laboratory syntheses. We describe two families diamond-graphene (diaphite) phases constructed from layered bonded sp3 sp2 units provide a framework classifying members this class materials. nanocomposite structures are identified within both natural diamonds...
Abstract Electrocatalytic oxygen reduction reaction (ORR) has been intensively studied for environmentally benign applications. However, insufficient understanding of ORR 2 e − ‐pathway mechanism at the atomic level inhibits rational design catalysts with both high activity and selectivity, causing concerns including catalyst degradation due to Fenton or poor efficiency H O electrosynthesis. Herein we show that generally accepted electrocatalyst based on a Sabatier volcano plot argument...
In this paper, we present quantum mechanical (QM) calculations, at a periodic Hartee−Fock (HF) level, on the bulk and surface properties of cubic CeO2 ZrO2. We have investigated M−O bonding features, established high degree ionicity both materials, which is greater for than The calculated values C11, C12, C44 elastic constants, are in close agreement with experiment; an extended oxygen basis set, containing d-orbital polarization functions, essential to model accurately symmetry lowering...
Abstract The performance of hybrid exchange functionals is investigated within the framework Density Functional Theory (DFT), in describing properties cubic and tetragonal ferroelectric phases BaTiO3. A variable fraction ξ non-local HF mixed with Becke's GGA formulation, coupled LYP correlation functional. Standard DFT (LDA, PW, B3LYP) uncorrelated are also added for comparison. Inclusion has a noticeable effect on calculated electronic density, several observables show clear trends as...
The structural and electronic properties of bulk cubic tetragonal tungsten trioxide are investigated using a periodic boundary condition ab initio Hartree−Fock method; posteriori density functional corrections used to estimate the effect electron correlation on energy. forces involved in bonding between metal oxygen examined shed light crystal chemistry compound. While phase is highly ionic, symmetry distortion leading causes an increase covalence its nearest oxygen. observed instability WO3...
Dark-colored shiny flakes of graphitic carbon nitride materials produced by reacting dicyandiamide C2N4H4 in a KBr/LiBr molten salt medium were determined to have C/N ratio near 1.2:1. The compounds also contained 2.3–2.5 wt % H incorporated within N–H species identified Fourier transform infrared spectroscopy. One recent study revealed analogous results for thin films an similar synthesis method, while previous investigation instead reported formation crystalline gC3N4 with triazine-based...
Combining long-range magnetic order with polarity in the same structure is a prerequisite for design of (magnetoelectric) multiferroic materials. There are now several demonstrated strategies to achieve this goal, but retaining above room temperature remains difficult target. Iron oxides +3 oxidation state have high ordering temperatures due size coupled moments. Here we prepare and characterize ScFeO(3) (SFO), which under pressure strain-stabilized thin films adopts polar variant corundum...
Graphitic carbon nitrides are investigated for developing highly durable Pt electrocatalyst supports polymer electrolyte fuel cells (PEFCs). Three different graphitic nitride materials were synthesized with the aim to address effect of crystallinity, porosity, and composition on catalyst support properties: polymeric (gCNM), poly(triazine) imide (PTI/Li+Cl-), boron-doped (B-gCNM). Following accelerated corrosion testing, all found be more electrochemically stable compared conventional black...
Abstract Nano‐sized α‐MnO 2 nanorods doped with Co or Ru were directly synthesized using a continuous hydrothermal synthesis process (production rate 10 g h −1 ) and investigated as relatively inexpensive (due to the small content) bifunctional catalysts for both Oxygen Reduction Reaction (ORR) Evolution (OER). The materials extensively characterized range of analytical methods; these including Extended X‐Ray Absorption Fine Structure (EXAFS) spectroscopy measurements, which was accompanied...