Based on the V-shaped linker molecule 4,4'-benzophenonedicarboxylic acid, the new carbonyl-functionalized metal-organic framework (MOF) [Al(OH)(O(2)C-C(6)H(4)-CO-C(6)H(4)-CO(2))], denoted as CAU-8, was discovered employing high-throughput methods. The compound is obtained from 4,4'-benzophenonedicarboxylic acid, Al(2)(SO(4))(3)·18H(2)O in a mixture of N,N-dimethylformamide (DMF) and water under solvothermal conditions. The structure was determined from single-crystal X-ray diffraction data (I4(1)/a, a = b = 13.0625(5), c = 52.565(2) Å). The framework is based on infinite inorganic building units of trans-connected, corner-sharing AlO(6)-polyhedra. Parallel Al-O-chains are arranged in layers perpendicular to [001]. Within a layer an interchain distance of ∼1.1 nm is observed. The orientation of the Al-O-chains within neighboring layers is perpendicular to each other, along [100] and [010], respectively, and an ABCDA stacking of these layers is observed. The interconnection of these orthogonally oriented chains by the V-shaped dicarboxylate ions results in the formation a three-dimensional framework structure containing one-dimensional channels with a diameter of about 8 Å. The pore walls are lined by the keto-groups. CAU-8 was thoroughly characterized by X-ray powder diffraction (XRPD), thermogravimetric measurements, IR- and Raman-spectroscopy, elemental analysis, and gas sorption experiments using N(2) and H(2) as adsorptives. CAU-8 is stable up to 350 °C in air and exhibits a moderate porosity with a specific surface area of S(BET) = 600 m(2)/g and a micropore volume of 0.23 cm(3)/g. Moreover, a detailed topological analysis of the framework was carried out, and an approach for the topological analysis of MOFs based on infinite 1-periodic building units is proposed.

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Graphenes as metal-free catalysts for the oxidative depolymerization of lignin modelsJuan F. Blandez, [b] Sergio Navalón, [b] Mercedes Alvaro, [b] and Hermenegildo Garcia* [a] Abstract: Graphene oxide promotes the oxidative degradation of guaiacylglycerol-β-guaiacyl ether, a lignin model compound, in different solvents including acetonitrile, toluene and water mainly to guaiacol, 2-methoxyquinone, vanillic acid and coniferyl aldehyde.Reduced graphene oxide and B-doped graphene exhibit similar activity as graphene oxide. Control experiments indicate that metal impurities should play a marginal role in the observed catalytic activity.

The in situ and systematic high-throughput investigation of the system Al/4,4'-benzophenonedicarboxylic acid (HBPDC)/DMF/HO in the presence of various additives was carried out, and a new Al-MOF of composition [Al(OH)(BPDC)], denoted as CAU-21-BPDC, was obtained. Its crystal structure was determined from single-crystal X-ray diffraction data (space group I422, a = b = 17.2528(7) Å, c = 23.864(1) Å). The structure is built up by octanuclear rings of cis corner-sharing AlO polyhedra forming the inorganic building unit (IBU). These {AlO} IBUs are arranged in a bcu packing and connected via BPDC ions in a way that each IBU is linked via two linker molecules to each of the eight adjacent IBUs. Thus, accessible, one-dimensional modulated pores with a diameter between 3.6 and 6.5 Å are formed. In addition, tetrahedral cavities are formed by the BPDC linker molecules. The framework of CAU-21-BPDC is polymorphous with that of CAU-8-BPDC, which contains one-dimensional chains of trans corner-sharing AlO polyhedra connected by BPDC ions. Replacing HBPDC by 4,4'-oxydibenzoic acid (HODB), which contains an oxygen atom between the phenyl rings instead of a keto group, leads to the synthesis of Al-MOFs isoreticular with CAU-8-BPDC and CAU-21-BPDC. In addition, a coordination polymer, [Al(HODB)(OH)], was discovered and structurally characterized. The structure of CAU-8-ODB was refined from powder X-ray diffraction data, while a Pawley refinement was carried out for CAU-21-ODB to determine the lattice parameters and confirm phase purity. The structure of CAU-21-ODB was confirmed using density functional theory (DFT) calculations. A thorough characterization shows that the CAU-8 and CAU-21-type structures are stable up to 350 and 300 °C in air, respectively, almost independent of the linker molecules incorporated. The former MOFs are porous toward N and CO, while the latter only adsorb CO.

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Wurtzite‐phase ZnS nanodot films with controllable dot density can be prepared at low temperature by a technique known as Spray‐ILGAR (ILGAR = ion‐layer gas reaction), without organic surfactant. ZnS nanodots covered with homogenous In2S3 (as the point‐contact bridge) act as a defect passivation layer and form a structured buffer layer. This ZnS/In2S3 buffer improves cell efficiencies by up to about 1%–1.5% compared to reference cells with a pure ILGAR In2S3 buffer.

Novel thin film composite photocathodes based on device‐grade Cu(In,Ga)Se2 chalcopyrite thin film absorbers and transparent conductive oxide Pt‐implemented TiO2 layers on top are presented for an efficient and stable solar‐driven hydrogen evolution. Thin films of phase‐pure anatase TiO2 are implemented with varying Pt‐concentrations in order to optimize simultaneously i) conductivity of the films, ii) electrocatalytic activity, and iii) light‐guidance toward the chalcopyrite. Thereby, high incident‐photon‐to‐current‐efficiencies of more than 80% can be achieved over the full visible light range. In acidic electrolyte (pH 0.3), the most efficient Pt‐implemented TiO2–Cu(In,Ga)Se2 composite electrodes reveal i) photocurrent densities up to 38 mA cm−2 in the saturation region (−0.4 V RHE, reversible hydrogen electrode), ii) 15 mA cm−2 at the thermodynamic potential for H2‐evolution (0 V RHE), and iii) an anodic onset potential shift for the hydrogen evolution (+0.23 V RHE). It is shown that the gradual increase of the Pt‐concentration within the TiO2 layers passes through an efficiency‐ and stability‐maximum of the device (5 vol% of Pt precursor solution). At this maximum, optimized light‐incoupling into the device‐grade chalcopyrite light‐absorber as well as electron conductance properties within the surface layer are achieved while no degradation are observed over more than 24 h of operation.

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