Xiaohua Guo

Synthesis and characterization of Cu2O/Au and its application in catalytic reduction of 4-nitrophenol

Monodispersed Cu2O spherical colloids with diameter of about 300 nm were prepared by a facile additive-assisted complex-precursor solution method. Core-shell structure Cu2O/Au composites, constructed by spherical Cu2O core and Au nanoparticles shell, were obtained via galvanic replacement method. The morphology, microstructure and optical properties of the Cu2O/Au composites were characterized by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectra and ultraviolet-visible absorption. The results showed that Au NPs with an average size of 12 nm were uniformly distributed on the surface of the Cu2O spheres with size about 300 nm. Cu2O/Au composites exhibit high catalytic activity toward 4-NP reduction at room temperature.

Modification on C217 by auxiliary acceptor toward efficient sensitiser for dye-sensitised solar cells: a theoretical study

ABSTRACT In this work, to develop efficient organic dye sensitisers, a series of novel donor–acceptor–π–acceptor metal-free dyes were designed based on the C217 dye by means of modifying different auxiliary acceptors, and their photovoltaic performances were theoretically investigated with systematic density functional theory calculations coupled with the incoherent charge-hopping model. Results showed that the designed dyes possess lower highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) levels as well as narrower HOMO–LUMO gaps compared to C217, which indicate their higher light-harvesting efficiency. In addition, using the (TiO2)38 cluster and bidentate bridging model, we predicted that the photoelectric conversion efficiency (PCE) for the C217 dye is as high as 9.92% under air mass (AM) 1.5 illumination (100 mW·cm−2), which is in good agreement with its experimental value (9.60%–9.90%). More interestingly, the cell sensitised by the dye 7 designed in this work exhibits a middle-sized open-circuit voltage of 0.737 V, large short-circuit photocurrent density of 21.16 mAˑcm−2 and a fill factor of 0.801, corresponding to a quite high PCE of 12.49%, denoting the dye 7 is a more promising sensitiser candidate than the C217, and is worth further experimental study.

CoFe2O4@TiO2@Au Core-Shell Structured Microspheres: Synthesis and Photocatalyltic Properties

A facile and efficient method for fabrication of magnetic composite microspheres CoFe2O4@TiO2@Au is demonstrated. The shells of anatase TiO2 were coated onto a magnetic CoFe2O4 core via liquid-phase deposition procedure, and then Au nanoparticles were deposited onto CoFe2O4@TiO2 microspheres through seed-mediated growth. XRD, TEM, and VSM were used to investigate the structure, morphology and magnetic properties of the samples, their photocatalytic activity were also tested. Heterostructure of CoFe2O4@TiO2@Au was confirmed by different measurements. Compared to unmodified CoFe2O4@TiO2 microspheres, CoFe2O4@TiO2@Au microspheres showed higher photocatalytic activity for Rhodamine B (RhB) degradation in water.

Synthesis, crystal structure, and luminescent property of two novel Zn/Co(II) coordination polymers with a linear bis-imidazole and dicarboxylate ligands

The linear linker 1,3-bis(2-methylimidazolyl)propane (Bmip) has been used to construct two new coordination polymers with Zn2+ and Co2+ ions and carboxylate donor ligand viz., 4,4’-oxydibenzoic acid (H2Oba). Compounds formed hydrothermally are [Zn(Bmip)(Oba)]n (Ι), [Co(Bmip)(Oba)]n (II). Complexes Ι and II have been characterized by single crystal X-ray diffraction (CIF files CCDC nos. 1033354 (I), 1001813 (II)), IR spectroscopy, thermogravimetry, elemental analysis and powder X-ray diffraction. Single crystal X-ray analysis revealed that complexes Ι and II are isostructural, which exhibit 2D 44-sql net. And the adjacent 44-sql net are further inforced through weak noncovalent C–H···π and H-bonding to form a 3D supramolecular framework. Furthermore, the photoluminescence property of complexes Ι and II in the solid state at room temperature was also investigated.