Enhancing Hydrogen Evolution Reaction via Synergistic Interaction between the [MoS] Cluster Co-Catalyst and WSe Photocathode.

A thiomolybdate [MoS] nanocluster is a promising catalyst for hydrogen evolution reaction (HER) due to the high number of active edge sites. In this work, thiomolybdate cluster films are prepared by spin-coating of a (NH)MoS solution both on FTO glass substrates as hydrogen evolving electrodes and on highly 00.1-textured WSe for photoelectrochemical water splitting.

On the Origin of the OER Activity of Ultrathin Manganese Oxide Films.

There is an urgent need for cheap, stable, and abundant catalyst materials for photoelectrochemical water splitting. Manganese oxide is an interesting candidate as an oxygen evolution reaction (OER) catalyst, but the minimum thickness above which MnO thin films become OER-active has not yet been established. In this work, ultrathin (<10 nm) manganese oxide films are grown on silicon by atomic layer deposition to study the origin of OER activity under alkaline conditions.

Angular momentum-induced delays in solid-state photoemission enhanced by intra-atomic interactions.

Attosecond time-resolved photoemission spectroscopy reveals that photoemission from solids is not yet fully understood. The relative emission delays between four photoemission channels measured for the van der Waals crystal tungsten diselenide (WSe) can only be explained by accounting for both propagation and intra-atomic delays. The intra-atomic delay depends on the angular momentum of the initial localized state and is determined by intra-atomic interactions.

On an Easy Way To Prepare Metal-Nitrogen Doped Carbon with Exclusive Presence of MeN4-type Sites Active for the ORR.

Today, most metal and nitrogen doped carbon catalysts for ORR reveal a heterogeneous composition. This can be reasoned by a nonoptimized precursor composition and various steps in the preparation process to get the required active material. The significant presence of inorganic metal species interferes with the assignment of descriptors related to the ORR activity and stability.

Microcontact-printing-assisted access of graphitic carbon nitride films with favorable textures toward photoelectrochemical application.

An "ink" (cyanamide) infiltrated anodic aluminum oxide (AAO) stamp is found capable of printing carbon nitride films featuring regular microstructures of the stamp onto the substrates via in situ "chemical vapor deposition". A photocurrent density of 30.2 μA cm(-2 --) at 1.

Photoelectrochemical properties of (In,Ga)N nanowires for water splitting investigated by in situ electrochemical mass spectroscopy.

We investigated the photoelectrochemical properties of both n- and p-type (In,Ga)N nanowires (NWs) for water splitting by in situ electrochemical mass spectroscopy (EMS). All NWs were prepared by plasma-assisted molecular beam epitaxy. Under illumination, the n-(In,Ga)N NWs exhibited an anodic photocurrent, however, no O2 but only N2 evolution was detected by EMS, indicating that the photocurrent was related to photocorrosion rather than water oxidation.

Surface aspects of sol-gel derived hematite films for the photoelectrochemical oxidation of water.

α-Fe(2)O(3) (hematite) photoanodes for the oxygen evolution reaction (OER) were prepared by a cost-efficient sol-gel procedure. Due to low active photoelectrochemical properties observed, it is assumed that the sol-gel procedure leads to hematite films with defects and surface states on which generated charge carriers are recombined or immobilized in trap processes. Electrochemical activation was proven to diminish unfavourable surface groups to some extent.

Ruthenium sulphide thin layers as catalysts for the electrooxidation of water.

Crystalline RuS(2) layers were prepared on titanium sheets by reactive magnetron sputtering using a metallic ruthenium target and a H(2)S-Ar mixture as process gas. The ability of these layers for the electrooxidation of water (OER) was investigated by differential electrochemical mass spectrometry (DEMS) in 0.5 M H(2)SO(4) electrolyte.

Automated quantitative 3D analysis of faceting of particles in tomographic datasets.

Characterization of facets of particles is a common problem. In this paper an algorithm is presented which allows automated quantitative 3D analysis of facets of many particles within tomographic datasets. The algorithm is based on the analysis of probability distributions of the orientations of triangle normals of mesh representations.

Structure of the catalytic sites in Fe/N/C-catalysts for O2-reduction in PEM fuel cells.

Fe-based catalytic sites for the reduction of oxygen in acidic medium have been identified by (57)Fe Mössbauer spectroscopy of Fe/N/C catalysts containing 0.03 to 1.55 wt% Fe, which were prepared by impregnation of iron acetate on carbon black followed by heat-treatment in NH(3) at 950 °C.

Unveiling N-protonation and anion-binding effects on Fe/N/C-catalysts for O reduction in PEM fuel cells.

The high cost of proton-exchange-membrane fuel cells would be considerably reduced if platinumbased catalysts were replaced by iron-based substitutes, which have recently demonstrated comparable activity for oxygen reduction, but whose cause of activity decay in acidic medium has been elusive. Here, we reveal that the activity of Fe/N/C-catalysts prepared through a pyrolysis in NH is mostly imparted by acid-resistant FeN-sites whose turnover frequency for the O reduction can be regulated by fine chemical changes of the catalyst surface. We show that surface N-groups protonate at pH 1 and subsequently bind anions.

Quantitative structural assessment of heterogeneous catalysts by electron tomography.

We present transmission electron microscope (TEM) tomography investigations of ruthenium-based fuel cell catalyst materials as employed in direct methanol fuel cells (DMFC). The digital three-dimensional representation of the samples not only enables detailed studies on number, size, and shape but also on the local orientation of the ruthenium particles to their support and their freely accessible surface area. The shape analysis shows the ruthenium particles deviate significantly from spherical symmetry which increases their surface to volume ratio.