Tin‐based chalcogenide semiconductors, though attractive materials for photovoltaics, have to date exhibited poor performance and stability for photoelectrochemical applications. Here, a novel strategy is reported to improve performance and stability of tin monosulfide (SnS) nanoplatelet thin films for H2 production in acidic media without any use of sacrificial reagent. P‐type SnS nanoplatelet films are coated with the n‐CdS buffer layer and the TiO2 passivation layer to form type II heterojunction photocathodes. These photocathodes with subsequent deposition of Pt nanoparticles generate a photovoltage of 300 mV and a photocurrent density of 2.4 mA cm−2 at 0 V versus reversible hydrogen electrode (RHE) for water splitting under simulated visible‐light illumination (λ > 500 nm, P in = 80 mW cm−2). The incident photon‐to‐current efficiency at 0 V versus RHE for H2 production reach a maximum of 12.7% at 575 nm with internal quantum efficiency of 13.8%. The faradaic efficiency for hydrogen evolution remains close to unity after 6000 s of illumination, confirming the robustness of the heterojunction for solar H2 production.

No abstract

Large aqueous ions are interesting because they are useful in materials science (for example to generate thin films) but also because they serve as molecular models for the oxide-aqueous mineral interface where spectroscopy is difficult. Here we show that new clusters of the type M[(μ-OH) Co(NH ) ] (NO ) (M=Al, Ga) can be synthesized using Werner's century-old cluster as a substitutable framework. We substituted Group 13 metals into the hexol Co[(μ-OH) Co(NH ) ] ion to make diamagnetic heterometallic ions. The solid-state structure of the hexol-type derivatives were determined by single-crystal XRD and NMR spectroscopy and confirmed that the solid-state structure persists in solution after dissolution into either D O or [D ]DMSO. Other compositions besides these diamagnetic ions can undoubtedly be made using a similar approach, which considerably expands the number of stable aqueous heteronuclear ions.

No abstract

a b s t r a c tWe report enthalpies of formation from the elements and oxides, D f H = À(26195.31 ± 34.46) kJ Á mol À1 and D f;ox H = À(1402.09 ± 33.36) kJ Á mol À1 , for crystalline [Al 13 (l 3 -OH) 6 (l 2 -OH) 18 (H 2 O) 24 ](NO 3 ) 15 Á 11H 2 O (cr) (flat-Al 13 ) measured using aqueous solution room temperature calorimetry. This material is a nitrate salt of a polynuclear aluminum hydroxide ion with thirteen aluminum metal centers, Al 13 15+ .Unlike the e-Al 13 7+ Keggin ion, it contains solely octahedrally coordinated aluminum in a more flat topology. We also report heat capacities from temperatures of (2 to 300) K on this flat-Al 13 nitrate using a Quantum Design Physical Property Measurement System (PPMS). These measurements were used to calculate the standard molar entropy and subsequently the free energy of formation for this material. We observed that during the heat capacity measurements, the flat-Al 13 sample underwent a second order phase transition near T = 214 K.

No abstract

No abstract

No abstract