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• The synthesis of In (III) metal –organic framework with LH 2 ligand via the sonochemical method has been reported. • Three metal–organic compounds of Zr (IV), In (III) and Zn (II) were introduced into the perovskite layer to control the crystallization and film formation. • The hydroxyl and carboxyl groups in pyda and pydcH 2 ligands intract with ions to influence growth mechanism and quality of perovskite films. • The power conversion efficiency of fabricated PSCs increased more than 90% improvement after adding 2 wt% of zinc metal–organic framework in HTM-free conditions. The study aimed to investigate the role of the metal–organic frameworks in the perovskite solution, and their effects on perovskite crystal, absorption, film formation, and device performance. Three supramolecular compounds of Zirconium(IV), Indium(III) and Zinc(II) with proton transfer compound, obtained from 2,6-pyridinedicarboxylic acid and 2,6-pyridinediamine, were synthesized, and characterized and used as additives in perovskite solar cells. The additives with different amounts were added to the CH 3 NH 3 PbI 3 solutions to control the morphology of the perovskite layer during the film formation process. More importantly, the metal–organic frameworks serving as additives can help to form a better perovskite layer with fewer voids between CH 3 NH 3 PbI 3 domains during phase transformation. The findings showed that using a 2 wt% of zinc metal–organic framework in the perovskite layer achieved yields results in the performance of perovskite solar cells. As a result, the current density (Jsc) of the new device increased from 7.02 to 9.36 mA/cm2, and the Fill-Factor (FF) of the device improved from 0.42 to 0.62 for 2 wt% of zinc metal–organic framework. Also, the PCE (Efficiency) of perovskite solar cells achieved more than 90% of improvement after adding 2 wt% of zinc metal–organic framework as an additive in HTM-free conditions. FE-SEM and XRD studied the morphology of this new perovskite layer. [ABSTRACT FROM AUTHOR]

New hydrazinium hydro- closo -borates with [B n H n ]2– anions (n = 10 and 12) were obtained by direct reaction of the free acids (H 3 O) 2 [B n H n ] with hydrazinium hydrate (N 2 H 4 · x H 2 O) in aqueous solution. The three new compounds (N 2 H 5) 2 [B 10 H 10 ], (N 2 H 5) 2 [B 10 H 10 ] · 2 N 2 H 4 and (N 2 H 5) 2 [B 12 H 12 ] · 2 N 2 H 4 crystallize in the space groups P 2 1 / c , C 2/ c and P 1 ‾ , respectively. They contain up to 11 wt-% hydrogen. Two main kinds of bonding were observed in all crystal structures, classical hydrogen bonds (Nδ––Hδ+⋯Nδ–) and dihydrogen bonding between the negatively polarized hydrogen of the boron clusters and positively polarized hydrogen in hydrazinium cations (Bδ+–Hδ–⋯Hδ+–Nδ–). Thermal decomposition analyses of these compounds show that they absorb energy first, and then release a huge amount of energy upon decomposition and collapse of the structure. Due to the differently polarized hydrogen atoms in these compounds, hydrogen molecules (H 2) are generated during the decomposition, which can be used as hydrogen fuel. • Hydro- closo -borate anions [B n H n ]2– (n = 10 and 12) with hydrazinium cations. • Crystal structures of (N 2 H 5) 2 [B 10 H 10 ], (N 2 H 5) 2 [B 10 H 10 ] · 2 N 2 H 4 and (N 2 H 5) 2 [B 12 H 12 ] · 2 N 2 H 4. • Thermal decomposition and DSC analysis of the (N 2 H 5) 2 [B 10 H 10 ] · 2 N 2 H 4 and (N 2 H 5) 2 [B 12 H 12 ] · 2 N 2 H 4. [ABSTRACT FROM AUTHOR]

Synthesis of Zn(II) supramolecules as precursors for the fabrication of the zinc oxide nanostructures is an important issue in nanomaterials research. In the present study, the Zn(II) supramolecular compound, [pyda.H] + 2 [Zn(pydc) 2 ] 2− {(pyda.H) + = pyridine-2,6-diamuniun, (pydc) 2− = pyridine-2,6-dicarboxylate}, has been prepared by sonochemical method in two different solvents and characterized by scanning electron microscopy (SEM), X-ray powder diffraction (XRD), 1 H and 13 C NMR spectroscopy, FT-IR spectroscopy, elemental analysis, and thermal gravimetric analysis. Two different kinds of ZnO nanoparticles with the average particle sizes of about 30 and 350 nm were obtained by thermal degradation of complexes prepared in dry methanol and deionized water as solvents, respectively. For preparing the photoanode of the dye sensitized solar cell (DSSC) based on ZnO nanocomposite, the obtained nanopowders were used to act as transparent and scattering layers. The ZnO-based DSSCs were fabricated by N719 Ruthenium dye and all photovoltaic parameters were measured as well. The electrochemical impedance spectroscopy technique has been used to study the DSSCS performance. As a result, a new type of ZnO based-DSSC with appropriate values of the conversion efficiency (1.22%) and the electron lifetime (30 ms) was obtained. [ABSTRACT FROM AUTHOR]

Nanocrystalline Ba 2 (In 1.8 Cr 0.2)O 5 ·(H 2 O) δ powders were synthesized via a polymerizable-complex method in two different ways, one based on citric acid and the other additionally on 2,6-pyridinedicarboxylic acid, 2,6-diaminopyridine, and polyethylene glycol. Crystal structure, surface area, thermochemical and optical properties were analyzed. The photocatalytic activity was measured by the reduction of CO 2 under H 2 gas flow. CO 2 adsorption at the catalyst surface is found to be a critical factor strongly affecting the reactivity. With this study, we demonstrate the importance of the surface states as a crucial parameter when developing better CO 2 photo-reduction catalysts. Image 1 • Successful synthesis of Cr-substituted Ba 2 In 2 O 5 ·(H 2 O) δ powders by wet chemistry. • As-synthesized powders showed 20 times higher photoactivity than P25 reference. • Photocatalytic activity was strongly affected by CO 2 adsorption on the photocatalyst surface. [ABSTRACT FROM AUTHOR]

Highlights: [•] Preparation of CdS/CdSe co-sensitized TiO2 photoanodes for QDSSCs. [•] Employing alloy, SILAR and spray pyrolysis methods. [•] Various conversion efficiencies measured equal to 3.18, 0.341 and 0.266%. [•] The sizes of CdS and CdSe QDs were obtained about 5 and 6nm. [•] The band gaps vary from 3.1eV to 2.38eV (TiO2/CdS (3)/CdSe). [ABSTRACT FROM AUTHOR]