Photocatalytic solar hydrogen production from water on a 100-m scale.

The unprecedented impact of human activity on Earth's climate and the ongoing increase in global energy demand have made the development of carbon-neutral energy sources ever more important. Hydrogen is an attractive and versatile energy carrier (and important and widely used chemical) obtainable from water through photocatalysis using sunlight, and through electrolysis driven by solar or wind energy. The most efficient solar hydrogen production schemes, which couple solar cells to electrolysis systems, reach solar-to-hydrogen (STH) energy conversion efficiencies of 30% at a laboratory scale.

Surface Modifications of (ZnSe)(CuGaSe) to Promote Photocatalytic Z-Scheme Overall Water Splitting.

Charge separation is crucial for an efficient artificial photosynthetic process, especially for narrow-bandgap metal sulfides/selenides. The present study demonstrates the application of a pn junction to particulate metal selenides to enhance photocatalytic Z-scheme overall water splitting (OWS). The constructed pn junction of CdS-(ZnSe)(CuGaSe) significantly boosted charge separation.

Self-activated Rh-Zr mixed oxide as a nonhazardous cocatalyst for photocatalytic hydrogen evolution.

Efficient, robust and environmentally friendly cocatalysts for photocatalysts are important for large-scale solar hydrogen production. Herein, we demonstrate that a Rh-Zr mixed oxide is an efficient cocatalyst for hydrogen evolution. Impregnation of Zr and Rh precursors (Zr/Rh = 5 wt/wt%) formed RhZrO cocatalyst particles on Al-doped SrTiO, which exhibited 31× higher photocatalytic water-splitting activity than a RhO cocatalyst.

Neutron diffraction experiment with the Y116S variant of transthyretin using iBIX at J-PARC: application of a new integration method.

Transthyretin (TTR) is one of more than 30 amyloidogenic proteins, and the amyloid fibrils found in patients afflicted with ATTR amyloidosis are composed of this protein. Wild-type TTR amyloids accumulate in the heart in senile systemic amyloidosis (SSA). ATTR amyloidosis occurs at a much younger age than SSA, and the affected individuals carry a TTR mutant.

Z-Scheme Water Splitting under Near-Ambient Pressure using a Zirconium Oxide Coating on Printable Photocatalyst Sheets.

Sunlight-driven water splitting systems operating under ambient pressure are essential for practical renewable hydrogen production. Printable photocatalyst sheets, composed of a hydrogen evolution photocatalyst (HEP), an oxygen evolution photocatalyst (OEP), and conductive metal nanoparticles, are cost-effective and scalable systems. However, the decrease in water splitting activity under ambient pressure due to reverse reactions hampers their practical application.

Neutron crystallography of copper amine oxidase reveals keto/enolate interconversion of the quinone cofactor and unusual proton sharing.

Recent advances in neutron crystallographic studies have provided structural bases for quantum behaviors of protons observed in enzymatic reactions. Thus, we resolved the neutron crystal structure of a bacterial copper (Cu) amine oxidase (CAO), which contains a prosthetic Cu ion and a protein-derived redox cofactor, topa quinone (TPQ). We solved hitherto unknown structures of the active site, including a keto/enolate equilibrium of the cofactor with a nonplanar quinone ring, unusual proton sharing between the cofactor and the catalytic base, and metal-induced deprotonation of a histidine residue that coordinates to the Cu.

Efficient photocatalytic hydrogen evolution on single-crystalline metal selenide particles with suitable cocatalysts.

It is important to improve the apparent quantum yields (AQYs) of narrow bandgap photocatalysts to achieve efficient H production. The present work demonstrates a particulate solid solution of zinc selenide and copper gallium selenide (denoted as ZnSe:CGSe) that evolves H efficiently and is responsive to visible light up to 725 nm. This material was synthesized using a flux-assisted method and was found to comprise single-crystalline tetrahedral particles.

Efficient Water Oxidation Using Ta N Thin Film Photoelectrodes Prepared on Insulating Transparent Substrates.

Photoelectrochemical (PEC) water splitting using visible-light-responsive photoelectrodes is the preferred approach to converting solar energy into hydrogen as a renewable energy source. A transparent Ta N photoanode embedded within a PEC cell having a tandem configuration is a promising configuration that may provide a high solar-to-hydrogen energy conversion efficiency. Ta N thin films are typically prepared by heating precursor films in an NH flow at high temperatures, which tends to degrade the transparent conductive layer, such that producing efficient Ta N transparent photoanodes is challenging.

Current status and near future plan of neutron protein crystallography at J-PARC.

The IBARAKI Biological Crystal Diffractometer (iBIX) has been available for use at MLF (Material and Life Science Facility) in J-PARC (Japan Proton Accelerator Research Complex) since 2008. The development in state-of-the-art detector systems could enable iBIX to become one of the highest-performance neutron single-crystal diffractometers in the world. Here, together with other various developments, such as data reduction software, crystal growth, and new techniques in measurement coupled analysis, we provided new hydrogen and water structural data of several proteins and macromolecules.

Phase segregated Cu Se/NiSe bimetallic selenide nanocrystals formed through the cation exchange reaction for active water oxidation precatalysts.

Control over the composition and nanostructure of solid electrocatalysts is quite important for drastic improvement of their performance. The cation exchange reaction of nanocrystals (NCs) has been reported as the way to provide metastable crystal structures and complicated functional nanostructures that are not accessible by conventional synthetic methods. Herein we demonstrate the cation exchange-derived formation of metastable spinel NiSe NCs (sp-NiSe) and phase segregated berzelianite Cu Se (ber-Cu Se)/sp-NiSe heterostructured NCs as active oxygen evolution reaction (OER) catalysts.

Evaluation of permeability applicability based on continuum mechanics law in fluid flow through graphene membrane.

Graphene is expected to be used in separation applications such as desalination. However, it is difficult to predict the flow phenomena at the nanoscale using the conventional continuum law. Particularly at a Knudsen number (Kn) of >0.

Oxysulfide photocatalyst for visible-light-driven overall water splitting.

Oxysulfide semiconductors have narrow bandgaps suitable for water splitting under visible-light irradiation, because the electronegative sulfide ions negatively shift the valence band edges of the corresponding oxides. However, the instability of sulfide ions during the water oxidation is a critical obstacle to simultaneous evolution of hydrogen and oxygen. Here, we demonstrate the activation and stabilization of YTiOS, with a bandgap of 1.

An Al-doped SrTiO photocatalyst maintaining sunlight-driven overall water splitting activity for over 1000 h of constant illumination.

Photocatalytic water splitting is a viable approach to the large-scale production of renewable solar hydrogen. The apparent quantum yield for this reaction has been improved, but the lifespan of photocatalysts functioning under sunlight at ambient pressure have rarely been examined, despite the critical importance of this factor in practical applications. Herein, we show that Al-doped SrTiO (SrTiO:Al) loaded with a RhCrO (rhodium chromium oxide) cocatalyst splits water with an apparent quantum yield greater than 50% at 365 nm.

Transparent Ta N Photoanodes for Efficient Oxygen Evolution toward the Development of Tandem Cells.

Photoelectrochemical water splitting is regarded as a promising approach to the production of hydrogen, and the development of efficient photoelectrodes is one aspect of realizing practical systems. In this work, transparent Ta N photoanodes were fabricated on n-type GaN/sapphire substrates to promote O evolution in tandem with a photocathode, to realize overall water splitting. Following the incorporation of an underlying GaN layer, a photocurrent of 6.

Efficient hydrogen evolution on (CuInS)(ZnS) solid solution-based photocathodes under simulated sunlight.

A thin film of (CuInS2)x(ZnS)1-x has been developed as a photocathode for solar water splitting for the first time. A superior photoelectrochemical performance has been achieved, mainly attributed to the formation of a solid solution by CuInS2 and ZnS, which proved to be an effective strategy to improve the onset potential and efficiency of CuInS2 photocathodes.

Status of the neutron time-of-flight single-crystal diffraction data-processing software STARGazer.

The STARGazer data-processing software is used for neutron time-of-flight (TOF) single-crystal diffraction data collected using the IBARAKI Biological Crystal Diffractometer (iBIX) at the Japan Proton Accelerator Research Complex (J-PARC). This software creates hkl intensity data from three-dimensional (x, y, TOF) diffraction data. STARGazer is composed of a data-processing component and a data-visualization component.

Phase-segregated NiP @FeP O core@shell nanoparticles: ready-to-use nanocatalysts for electro- and photo-catalytic water oxidation through activation by structural transformation and spontaneous ligand removal.

The high overpotential of the oxygen evolution reaction is a critical issue to be overcome to realize efficient overall water splitting and enable hydrogen generation powered by sunlight. Homogeneous and stable nanoparticles (NPs) dispersed in solvents are useful as both electrocatalysts and cocatalysts of photocatalysts for the electro- and photo-catalytic oxygen evolution reaction, respectively, through their adsorption on various electrode substrates. Here, phase-segregated NiP @FeP O core@shell NPs are selectively synthesized by the reaction of Fe(CO) with amorphous NiP seed-NPs.

Effects of slit width on water permeation through graphene membrane by molecular dynamics simulations.

Graphene membranes can be used for nanoscale filtration to remove atoms and are expected to be used for separation. To realize high-permeability and high-filtration performance, we must understand the flow configuration in the nanochannels. In this study, we investigated the applicability of continuum-dynamics laws to water flow through a graphene slit.

Visible-Light-Responsive Photoanodes for Highly Active, Stable Water Oxidation.

Solar energy is a natural and effectively permanent resource and so the conversion of solar radiation into chemical or electrical energy is an attractive, although challenging, prospect. Photo-electrochemical (PEC) water splitting is a key aspect of producing hydrogen from solar power. However, practical water oxidation over photoanodes (in combination with water reduction at a photocathode) in PEC cells is currently difficult to achieve because of the large overpotentials in the reaction kinetics and the inefficient photoactivity of the semiconductors.

Overall water splitting by photoelectrochemical cells consisting of (ZnSe)(CuInGaSe) photocathodes and BiVO photoanodes.

The design of photoelectrochemical (PEC) cell structures that mitigate challenges related to mass transfer is the key to achieving efficient hydrogen production. A PEC cell based on an integrated photoelectrode incorporating (ZnSe)(CuInGaSe) strips and BiVO strips exhibited 1.0% solar-to-hydrogen energy conversion efficiency even without stirring the electrolyte solution.

In Situ STM and Vibrational Study of Nanometer-Scale Reorganization of a Phospholipid Monolayer Accompanied by Potential-Driven Headgroup Digestion.

In situ dynamic observation of model biological cell membranes, formed on a water/gold substrate interface, has been performed by the combination of electrochemical scanning tunneling microscopy and reflection infrared absorption vibrational spectroscopy. Monolayers of 1,2-dihexanoyl-sn-glycero-3-phosphocholine (DHPC) were formed on alkanethiol-modified gold surfaces in a buffer solution, and the microscopic phase transitions driven by electrochemical potential control were observed more in detail than our previous study on the same system [Electrochem. Commun.

Primary Volvulus of the Small Intestine Exhibiting Chylous Ascites: A Case Report.

Background: Primary volvulus of the small intestine associated with chylous ascites is very rare, with only four reported cases. In this paper, we report a new case of primary volvulus associated with chylous ascites.

Case Presentation: The patient was a 70-year-old man.

Highly Active GaN-Stabilized Ta N Thin-Film Photoanode for Solar Water Oxidation.

Ta N is a very promising photocatalyst for solar water splitting because of its wide spectrum solar energy utilization up to 600 nm and suitable energy band position straddling the water splitting redox reactions. However, its development has long been impeded by poor compatibility with electrolytes. Herein, we demonstrate a simple sputtering-nitridation process to fabricate high-performance Ta N film photoanodes owing to successful synthesis of the vital TaO precursors.

Particulate photocatalyst sheets for Z-scheme water splitting: advantages over powder suspension and photoelectrochemical systems and future challenges.

Water splitting using semiconductor photocatalysts has been attracting growing interest as a means of solar energy based conversion of water to hydrogen, a clean and renewable fuel. Z-scheme photocatalytic water splitting based on the two-step excitation of an oxygen evolution photocatalyst (OEP) and a hydrogen evolution photocatalyst (HEP) is a promising approach toward the utilisation of visible light. In particular, a photocatalyst sheet system consisting of HEP and OEP particles embedded in a conductive layer has been recently proposed as a new means of obtaining efficient and scalable redox mediator-free Z-scheme solar water splitting.

Particulate Photocatalyst Sheets Based on Carbon Conductor Layer for Efficient Z-Scheme Pure-Water Splitting at Ambient Pressure.

Development of sunlight-driven water splitting systems with high efficiency, scalability, and cost-competitiveness is a central issue for mass production of solar hydrogen as a renewable and storable energy carrier. Photocatalyst sheets comprising a particulate hydrogen evolution photocatalyst (HEP) and an oxygen evolution photocatalyst (OEP) embedded in a conductive thin film can realize efficient and scalable solar hydrogen production using Z-scheme water splitting. However, the use of expensive precious metal thin films that also promote reverse reactions is a major obstacle to developing a cost-effective process at ambient pressure.