Li-Hua Gao

Hybrid self-assembled multilayer film formed by alternating layers of H4SiW12O40 and 1,10-diaminodecane (DAD)

A hybrid self-assembled multilayer film was prepared by alternating adsorption of H{sub 4}SiW{sub 12}O{sub 40} and 1,10-diaminodecane. The film was uniformly deposited and was found to be photochromic, as monitored by the UV spectroscopy. The film was also studied by X-ray photoelectron spectroscopy.

Preparation and Photoelectric Conversion of Dipolar Hemicyanine Dye/Polyoxometalate Self-Assembled Films

A new inorganic-organic hybrid self-assembled film was prepared by alternative adsorption of polyoxometalate (K10P2W18Cd4(H2O)2O68) and dipolar hemicyanine dye (H 6 ) and studied by UV-Vis spec- troscopy and photoelectrochemistry. The film was uniformly deposited with controllable layer number, red-shifted visible absorption band, and stable and large photoelectric signal. The effects of bias voltages, electron donor and electron acceptor on the photocurrent generation were discussed.

Electrochemical and enhanced photoelectrochemical properties of a hybrid film composed of anionic sandwich-type heteropolyoxotungstate and cationic hemicyanine

A new inorganic–organic hybrid film, consisting of a sandwich-type [ZnWMn2(H2O)2(ZnW9O34)2]12− (ZnWMn) polyanion and a hemicyanine cation of (E)-1,1′-(hexane-1,6-diyl)bis(4-(4-(dimethylamino)styryl)pyridinium) (H6), (ZnWMn/H6)n, has been deposited on quartz and indium-tin-oxide substrates through electrostatic self-assembly and studied by means of UV–vis spectroscopy, cyclic voltammetry and photoelectrochemical techniques. A uniformly deposition of the two film-forming components, evident bathochromic shift of visible absorption band of the films, compacted and ZnWMn-based quasi-reversible redox behaviours, large cathodic photocurrents of (ZnWMn/H6)n films are revealed. The effects of incorporation of ZnWMn as well as the experimental conditions including light intensities, applied bias potentials, electrolyte pH, and the film layer number on photocurrent generation of (ZnWMn/H6)n film are explored.Graphical AbstractA new hybrid electrostatically self-assembled film based on [ZnWMn2(H2O)2(ZnW9O34)2]12− (ZnWMn) polyanion and a hemicyanine cation of (E)-1,1′-(hexane-1,6-diyl)bis(4-(4-(dimethylamino)styryl)pyridinium) (H6) was uniformly deposited. The (ZnWMn/H6)n film-modified electrodes exhibited large steady cathodic photocurrent originated from excited H6*, but photocurrents generated from the (ZnWMn/H6)n film were enhanced by incorporating of ZnWMn anion.

Electrochemical and photoelectrochemical properties of a hybrid film made of Ru(II) complex and Zn(II)-substituted tungstoborate

A new hybrid film composed of Ru(II) polypyridyl complex cation of [(bpy)2Ru(L1)Ru(bpy)2]4+ {L1 = 1,6-bis-(2-(2-phenyl)benzimidazoyl)hexane, bpy = 2,2′-bipyridine, Ru1} and Zn(II)-substituted tungstoborate anion of [BW11Zn(H2O)O39]7− (BWZn) has been successfully prepared by electrostatic self-assembly technique and characterized by UV–visible absorption spectra, cycle voltammetry, electrochemical impedance spectra, as well as permeability of the films. Upon irradiation with white light, the hybrid films generated promptly stable and reproducible photocurrents which are related to applied potential, number of layer, and incident light intensity. The layer of BWZn anion as electron-transfer bridge layer can enhance photocurrent of the (BWZn/Ru1)n photoelectrochemical cell.

Photoelectrochemical properties of electrostatically self-assembled multilayer films formed by three bipolar hemicyanines and H{sub 4}SiW{sub 12}O{sub 40}

Graphical abstract: Display Omitted Highlight: ► Three self-assembled films of hemicyanines of and H{sub 4}SiW{sub 12}O{sub 40}. ► Uniformly deposited multilayers with reversible electrochemical activity. ► Large cathodic photocurrent densities of 0.36–1.02 μA/cm{sup 2} with IPCE of 0.75–0.98%. -- Abstract: The electrostatically self-assembled multilayer films of three bipolar hemicyanines with varied alkyl chain lengths were prepared by alternating adsorption of H{sub 4}SiW{sub 12}O{sub 40} and these hemicyanines, and characterized by UV–vis absorption spectroscopy, X-ray photoelectron spectroscopy and cyclic voltammetry. The results showed that these inorganic–organic composite films were uniformly deposited with good electrochemical activity. Photoelectrochemical investigations showed that the films exhibited large cathodic photocurrent densities of 0.36–1.02 μA/cm{sup 2} with the monochromatic incident photon-to-electron conversion efficiency of 0.75–0.98% while irradiated with 100 mW/cm{sup 2} polychromatic light (730 nm > λ > 325 nm) at an applied potential of −0.2 V vs. saturated calomel electrode, being strongly dependent on the alkyl chain lengths.