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A simple, low temperature solution process for Pb/Sn binary-metal perovskite planar-heterojunction solar cells is demonstrated. Sn inclusion substantially influences the band-gap, crystallization kinetics, and thin-film formation leading to a broadened light absorption and enhanced film coverage on ITO/PEDOT:PSS. As a result, the optimized device shows a PCE exceeding 10%, which is the best result for binary-metal perovskite solar cells so far., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A new synthetic method to fabricate Ti(3+)-modified, highly stable TiO2 photoanodes for H2O oxidation is reported. With Ti foil as both the conducting substrate and the Ti(3+)/Ti(4+) source, one-dimensional blue Ti(3+)/TiO2 crystals were grown by a one-step hydrothermal reaction. The concentration of Ti(3+) was further tuned by N2H4 reduction, leading to a greater photoelectrocatalytic activity, as evidenced by a high photocurrent density of 0.64 mA cm(-2) at 1.0 V vs RHE under simulated AM 1.5 G illumination. Electron paramagnetic resonance and Mott-Schottky plots reveal that higher charge-carrier density owing to N2H4 reduction contributes to the observed improvement. The generality of this synthesis method was demonstrated by its effectiveness in improving the performance of other types of photoanodes. By integrating the advantages of the 1D TiO2 architecture with those of Ti(3+) self-doping, this work provides a versatile tool toward the fabrication of efficient TiO2 photoanodes., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A hybrid WO3 /C3 N4 /CoOx system exhibits excellent photoelectrochemical activity for water oxidation. The system comprises a novel three-dimensionally branched WO3 nanosheet array coated with a layer of C3 N4 heterojunctions that are further decorated with CoOx nanoparticles. The photoelectrochemical activity arises from the effective light harvesting due to the 3D structure and "window effect," the excellent charge separation and transport in the heterojunction, and the fast interfacial charge collection and surface reactions due to the large surface area., (© 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A novel dopant-free TiO(2) photocatalyst (V(o)(.)-TiO(2)), which is self-modified by a large number of paramagnetic (single-electron-trapped) oxygen vacancies, was prepared by calcining a mixture of a porous amorphous TiO(2) precursor, imidazole, and hydrochloric acid at elevated temperature (450 °C) in air. Control experiments demonstrate that the porous TiO(2) precursor, imidazole, and hydrochloric acid are all necessary for the formation of V(o)(.)-TiO(2). Although the synthesis of V(o)(.)-TiO(2) originates from such a multicomponent system, this synthetic approach is facile, controllable, and reproducible. X-ray diffraction, XPS, and EPR spectroscopy reveal that the V(o)(.)-TiO(2) material with a high crystallinity embodies a mass of paramagnetic oxygen vacancies, and is free of other dopant species such as nitrogen and carbon. UV/Vis diffuse-reflectance spectroscopy and photoelectrochemical measurement demonstrate that V(o)(.)-TiO(2) is a stable visible-light-responsive material with photogenerated charge separation efficiency higher than N-TiO(2) and P25 under visible-light irradiation. The V(o)(.)-TiO(2) material exhibits not only satisfactory thermal- and photostability, but also superior photocatalytic activity for H(2) evolution (115 μmol h(-1) g(-1)) from water with methanol as sacrificial reagent under visible light (λ>400 nm) irradiation. Furthermore, the effects of reaction temperature, ratio of starting materials (imidazole:TiO(2) precursor) and calcination time on the photocatalytic activity and the microstructure of V(o)(.)-TiO(2) were elucidated., (Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)

A tale of two polyhedra: two nested Archimedean metal-organic polyhedra, a rhombicuboctahedron (Co(48) cage) and a cuboctahedron (Co(24) cage), have been assembled from two types of cobalt dimers and two complementary ligands. Within the 3D covalent cubic array of outer Co(48) cages and framework lie encapsulated inner Co(24) cages that are linked into a separate "hidden" 3D framework., (Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.)