Organic ionic plastic crystals having colossal barocaloric effects for sustainable refrigeration.

Barocaloric (BC) materials offer the potential for highly energy-efficient refrigeration by generating heat absorption through the effect of pressure on a solid-solid phase transition. However, very few of the known materials have the required phase transition in the temperature regions necessary for domestic refrigeration or air conditioning. We introduce organic ionic plastic crystals (OIPCs) as a new family of BC materials.

3D Printing to Enable Self-Breathing Fuel Cells.

Fuel cells rely on an effective distribution of the reactant gases and removal of the byproduct, that is, water. In this context, bipolar plates are the critical component for the effective management of these fluids, as these dictate to some extent the overall performance of polymer electrolyte membrane fuel cells (PEMFCs). Better bipolar plates can lead to a significant reduction in size, cost, and weight of fuel cells.

Hydrogen-Stabilized ScYNdGd Medium-Entropy Alloy for Hydrogen Storage.

The research on the functional properties of medium- and high-entropy alloys (MEAs and HEAs) has been in the spotlight recently. Many significant discoveries have been made lately in hydrogen-based economy-related research where these alloys may be utilized in all of its key sectors: water electrolysis, hydrogen storage, and fuel cell applications. Despite the rapid development of MEAs and HEAs with the ability to reversibly absorb hydrogen, the research is limited to transition-metal-based alloys that crystallize in body-centered cubic solid solution or Laves phase structures.

Light-Driven Reversible Hydrogen Storage in Light-Weight Metal Hydrides Enabled by Photothermal Effect.

Requiring high temperature for hydrogen storage is the main feature impeding practical application of light metal hydrides. Herein, to lift the restrictions associated with traditional electric heating, light is used as an alternative energy input, and a light-mediated catalytic strategy coupling photothermal and catalytic effects is proposed. With NaAlH as the initial target material, TiO nanoparticles uniformly distribute on carbon nanosheets (TiO @C), which couples the catalytic effect of TiO and photothermal property of C, is constructed to drive reversible hydrogen storage in NaAlH under light irradiation.

Core-shell NaBH @Ni Nanoarchitectures: A Platform for Tunable Hydrogen Storage.

The core-shell approach has surfaced as an attractive strategy to make complex hydrides reversible for hydrogen storage; however, no synthetic method exists for taking advantage of this approach. Here, a detailed investigation was undertaken to effectively design freestanding core-shell NaBH @Ni nanoarchitectures and correlate their hydrogen properties with structure and chemical composition. It was shown that the Ni shell growth on the surface of NaBH particles could be kinetically and thermodynamically controlled.

Synergistic ultraviolet and visible light photo-activation enables intensified low-temperature methanol synthesis over copper/zinc oxide/alumina.

Although photoexcitation has been employed to unlock the low-temperature equilibrium regimes of thermal catalysis, mechanism underlining potential interplay between electron excitations and surface chemical processes remains elusive. Here, we report an associative zinc oxide band-gap excitation and copper plasmonic excitation that can cooperatively promote methanol-production at the copper-zinc oxide interfacial perimeter of copper/zinc oxide/alumina (CZA) catalyst. Conversely, selective excitation of individual components only leads to the promotion of carbon monoxide production.

Renewable hydrogen for the chemical industry.

Hydrogen is often touted as the fuel of the future, but hydrogen is already an important feedstock for the chemical industry. This review highlights current means for hydrogen production and use, and the importance of progressing R&D along key technologies and policies to drive a cost reduction in renewable hydrogen production and enable the transition of chemical manufacturing toward green hydrogen as a feedstock and fuel. The chemical industry is at the core of what is considered a modern economy.

Hydrogen generation from a sodium borohydride-nickel core@shell structure under hydrolytic conditions.

Sodium borohydride (NaBH) is an attractive hydrogen carrier owing to its reactivity with water: it can generate 4 equivalents of H by hydrolysis (NaBH + 4HO → NaB(OH) + 4H). Since using NaBH in the solid state is the most favorable way to achieve a high gravimetric hydrogen storage capacity (theoretical maximum of 7.3 wt%), we have investigated the possibility of developing a core@shell nanocomposite (NaBH@Ni) where a metallic nickel catalyst facilitating the hydrolysis is directly supported onto NaBH nanoparticles.

Light-Activated Hydrogen Storage in Mg, LiH and NaAlH.

The concept of light activation for triggering hydrogen release or uptake in hydrogen storage materials was investigated with the aid of gold (Au) nanoparticles dispersed at the surface of typical hydrides including magnesium hydride (MgH ), lithium hydride (LiH) and sodium alanate (NaAlH ). Upon Xe lamp illumination, the overall temperature of the materials reached ca. 100 °C owing to the plasmonic heating effect of the Au nanoparticles.

Palladium nanoparticle functionalized graphene xerogel for catalytic dye reduction.

We report a method to synthesize a palladium-functionalized porous graphene xerogel structure. A graphene xerogel nanocomposite with a three-dimensional microstructure was obtained by chemical reduction of an aqueous dispersion of graphene oxide at mild temperature. After the graphene hydrogel has been placed in a K2PdCl4 solution, the spontaneous redox reaction between the reduced graphene and Pd2+ takes place, leading to the formation of nanohybrid materials consisting of a graphene porous matrix decorated with Pd nanoparticles.

Thermodynamics and performance of the Mg-H-F system for thermochemical energy storage applications.

Magnesium hydride (MgH) is a hydrogen storage material that operates at temperatures above 300 °C. Unfortunately, magnesium sintering occurs above 420 °C, inhibiting its application as a thermal energy storage material. In this study, the substitution of fluorine for hydrogen in MgH to form a range of Mg(HF) (x = 1, 0.

Production and purification of a soluble hydrogenase from Ralstonia eutropha H16 for potential hydrogen fuel cell applications.

The soluble hydrogenase (SH) from Ralstonia eutropha H16 is a promising candidate enzyme for H2-based biofuel application as it favours H2 oxidation and is relatively oxygen-tolerant. In this report, bioprocess development studies undertaken to produce and purify an active SH are described, based on the methods previously reported [1], [2], [3], [4]. Our modifications are: •Upstream method optimizations were undertaken on heterotrophic growth media and cell lysis involving ultrasonication.

Selective Photoactivation: From a Single Unit Monomer Insertion Reaction to Controlled Polymer Architectures.

Here, we exploit the selectivity of photoactivation of thiocarbonylthio compounds to implement two distinct organic and polymer synthetic methodologies: (1) a single unit monomer insertion (SUMI) reaction and (2) selective, controlled radical polymerization via a visible-light-mediated photoinduced electron/energy transfer-reversible addition-fragmentation chain transfer (PET-RAFT) process. In the first method, precise single unit monomer insertion into a dithiobenzoate with a high reaction yield (>97%) is reported using an organic photoredox catalyst, pheophorbide a (PheoA), under red light irradiation (λmax = 635 nm, 0.4 mW/cm(2)).

Materials, Chemistry, and Simulation for Future Energy Technology.

Special Issue: The Future of Energy. The science and engineering of clean energy now is becoming a multidisciplinary area, typically when new materials, chemistry, or mechanisms are met. "Trial and error" is the past.

Hydrogen Storage Materials for Mobile and Stationary Applications: Current State of the Art.

One of the limitations to the widespread use of hydrogen as an energy carrier is its storage in a safe and compact form. Herein, recent developments in effective high-capacity hydrogen storage materials are reviewed, with a special emphasis on light compounds, including those based on organic porous structures, boron, nitrogen, and aluminum. These elements and their related compounds hold the promise of high, reversible, and practical hydrogen storage capacity for mobile applications, including vehicles and portable power equipment, but also for the large scale and distributed storage of energy for stationary applications.

Synthesis of core-shell NaBH4@M (M = Co, Cu, Fe, Ni, Sn) nanoparticles leading to various morphologies and hydrogen storage properties.

Core-shell nanoparticles of sodium borohydride (NaBH4) coated with various metals have been successfully synthesised. The morphologies varied from spherical to cubic with a range of particle size distributions depending on the metal used. All core-shell structures show hydrogen storage reversibility with faster kinetics for NaBH4@Fe and NaBH4@Ni as compared to NaBH4@Cu.

Core--strategy leading to high reversible hydrogen storage capacity for NaBH4.

Owing to its high storage capacity (10.8 mass %), sodium borohydride (NaBH(4)) is a promising hydrogen storage material. However, the temperature for hydrogen release is high (>500 °C), and reversibility of the release is unachievable under reasonable conditions.

Functionalization of electropolished titanium surfaces with silane-based self-assembled monolayers and their application in drug delivery.

This work reports a novel and reproducible route for the successful modification of the surface of titanium (Ti) with self-assembled monolayers (SAMs). By electropolishing the surface of Ti, suitable physical/chemical surface properties were obtained for adequate growth of OctadecylTrichloroSilane (OTS) based SAM. Optimum conditions to achieve a well-organized and densely packed OTS film were also determined by monitoring the effect of different parameters including time, concentration, and temperature for OTS adsorption.

Remarkable hydrogen storage properties for nanocrystalline MgH2 synthesised by the hydrogenolysis of Grignard reagents.

The possibility of generating MgH(2) nanoparticles from Grignard reagents was investigated. To this aim, five Grignard compounds, i.e.

Calcium phosphate growth at electropolished titanium surfaces.

This work investigated the ability of electropolished Ti surface to induce Hydroxyapatite (HA) nucleation and growth in vitro via a biomimetic method in Simulated Body Fluid (SBF). The HA induction ability of Ti surface upon electropolishing was compared to that of Ti substrates modified with common chemical methods including alkali, acidic and hydrogen peroxide treatments. Our results revealed the excellent ability of electropolished Ti surfaces in inducing the formation of bone-like HA at the Ti/SBF interface.

Destabilisation of the Li-N-H hydrogen storage system with elemental Si.

A significant improvement in the dehydrogenation kinetics of the (LiNH(2) + LiH) system was obtained upon doping with elemental Si. Whilst, complete dehydrogenation of the (LiNH(2) + LiH) system requires more than 2 h, the time required for full dehydrogenation was reduced to less than 30 min by doping with elemental Si. It is observed that Si thermodynamically destabilises the system through the formation of novel intermediate phases resulting from the reaction of Si with both LiNH(2) and LiH.

Formation of OTS self-assembled monolayers at chemically treated titanium surfaces.

Enhanced biocompatibility of titanium implants highly depends on the possibility of achieving high degrees of surface functionalization for a low immune response and/or enhanced mineralization of bioactive minerals, such as hydroxyapatite. In this respect, surface modification with Self Assembled Monolayers (SAMs) has a great potential in delivering artificial surfaces of improved biocompatibility. Herein, the effectiveness of common chemical pre-treatments, i.

Destabilisation of complex hydrides through size effects.

Nanoparticles of NaAlH4, LiAlH4 and LiBH4 were prepared by encapsulating their respective hydrides within carbon nanotubes by a wet chemical approach. The resulting confinement had a profound effect on the overall hydrogen storage properties of these hydrides, with NaAlH4 and LiAlH4 releasing hydrogen from room temperature, for example.

Reaction paths between LiNH2 and LiH with effects of nitrides.

The solid-state reaction between LiNH2 and LiH potentially offers an effective route for hydrogen storage if it can be tailored to meet all the requirements for practical applications. To date, there still exists large uncertainty on the mechanism of the reaction--whether it is mediated by a transient NH3 or directly between LiNH2 and LiH. In an effort to clarify this issue and improve the reactivity, the effects of selected nitrides were investigated here by temperature-programmed desorption, X-ray diffraction, in-situ infrared analysis, and hydrogen titration.

The critical role of tryptophan-116 in the catalytic cycle of dimethylsulfoxide reductase from Rhodobacter capsulatus.

In dimethylsulfoxide reductase of Rhodobacter capsulatus tryptophan-116 forms a hydrogen bond with a single oxo ligand bound to the molybdenum ion. Mutation of this residue to phenylalanine affected the UV/visible spectrum of the purified Mo(VI) form of dimethylsulfoxide reductase resulting in the loss of the characteristic transition at 720 nm. Results of steady-state kinetic analysis and electrochemical studies suggest that tryptophan 116 plays a critical role in stabilizing the hexacoordinate monooxo Mo(VI) form of the enzyme and prevents the formation of a dioxo pentacoordinate Mo(VI) species, generated as a consequence of the dissociation of one of the dithiolene ligands of the molybdopterin cofactor from the Mo ion.