Fabrication of zinc sulphide hierarchical hollow spheres with photocatalytic property by a mild organic acid-assisted route
ABSTRACT Large quantities of zinc sulphide hierarchical hollow spheres were successfully obtained by a mild organic acid-assisted route using zinc chloride anhydrous and thiourea as precursors. Malonic acid played a key role as a structure-directing agent in driving such hierarchical hollow spheres structures. Certain amounts of malonic acid are necessary in formation of zinc sulphide hierarchical hollow spheres. The photocatalytic properties of as-synthesised zinc sulphide hierarchical hollow spheres have been studied, which shows an excellent photocatalytic activity for the degradation of rhodamine B under ultra-violet.
- Advanced Materials 10/2003; 15(20):1715 - 1719. · 14.83 Impact Factor
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ABSTRACT: Environmental problems associated with organic pollutants and toxic water pollutants provide the impetus for sustained fundamental and applied research in the area of environ- mental remediation. Semiconductor photocatalysis offers the potential for complete elimination of toxic chemicals through its efficiency and potentially broad applicability.(1) Various new compounds and materials for photocatalysis have been synthesized in the past few decades. A successful example is TiO2, a metal oxide often used as a catalyst in photochemistry, electrochemistry, environmental protection, and in the bat- tery industry.(2) Recently, transition-metal sulfides, in particular ZnS and CdS, have been intensively studied because of their unique catalytic functions compared to those of TiO2. (2, 3) These studies have revealed that ZnS nanocrystals (NCs) are good photocatalysts as a result of the rapid generation of electron- hole pairs by photoexcitation and the highly negative reduction potentials of excited electrons. The photocatalytic properties occur not only in the photoreductive production of H2 from water and the photoreduction of CO2, (4) but also in the phototransformation of various organic substrates such as the oxidative formation of carbon-carbon bonds from organic electron donors, cis-trans photoisomerization of alkenes, and the photoreduction of aldehydes and their derivatives.(5) The notable finding in nonmetalized ZnS photocatalysis is an irreversible two-electron-transfer photoreduction of organic substrates.(6) A favorable shift of the optical response into the visible region occurs subsequent to the doping of transition metal or rare-earth metal ions, such as Ni2+ and Cu2+; therefore, ZnS NCs can also be used as effective catalysts for photocatalytic evolution of H2 and photoreduction of toxic ions under visible-light irradiation.(7) An important application of ZnS is as a photocatalyst in environmental protection through the removal of organicAngewandte Chemie International Edition 01/2005; 44(8):1269 - 1273. · 13.73 Impact Factor
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ABSTRACT: Hierarchical ZnS structures with different sizes have been successfully prepared by a facile one-step method. By modulating the experimental parameters, we were able to fabricate hierarchical zinc sulfide (wurtzite) assembled structures with average sizes of 30, 200, and 400 nm on a large scale. Systematic experiments were carried out to investigate the factors such as the amounts of the reagents (thiourea and sodium hydroxide), which have great influence on the morphologies and sizes of the products. In addition, studies of the photocatalytic properties by exposure to UV light irradiation demonstrated that the as-obtained ZnS structures show potential photocatalytic activity. Therefore, the preparation and properties studies of different ZnS structures will offer great opportunities to explore the dependence of a material's properties on the morphology and size and find many interesting applications in the optoelectronic devices.Crystal Growth & Design - CRYST GROWTH DES. 11/2006; 7(1).