Journal ArticleDOI
Photochemical hydrogen production with cadmium sulfide suspensions
TLDR
In this article, photoetching of CdS microcrystals has been used to improve the efficiency of photochemical hydrogen production by irradiating suspensions of platinized cdS in various electrolyte solutions.Abstract:
Active photocatalysts for photochemical hydrogen production have been prepared by platinum deposition on microcrystals of CdS powders. Hydrogen produced by irradiating suspensions of platinized CdS in various electrolyte solutions (S/sup 2 -/, SO/sub 3//sup 2 -/, H/sub 2/PO/sup 2 -/) has been shown to be significantly improved by photoetching the CdS microcrystals. The efficiency of hydrogen formation in solutions containing S/sup 2 -/ is low due to the formation of disulfide ions. Additional of reducing agents such as sulfite or hypophosphite ions, which efficiently suppresses disulfide formation, allows hydrogen to evolve at a surprisingly high rate. In the case of a solution containing both S/sup 2/ and SO/sub 3//sup 2 -/ ions, the formation of thiosulfate is observed with a quantum yield of 0.25. In mixtures of sulfide and hypophosphite ions, phosphite and phosphate ions are the oxidation products. Hydrogen formation occurs in solutions containing SO/sub 3//sup 2 -/ ions only when the platinized CdS particles have previously been photoetched. Concomitant to the proton reduction, SO/sub 3//sup 2 -/ ions are oxidized to sulfate and dithionate. In 12 days, 9 L of H/sub 2/ was generated by irradiating 1 g of CdS/Pt suspended in an Na/sub 2/SO/sub 3/ solution. Aftermore » this period, the efficiency of the photocatalyst dropped to about 60% of the initial rate. The reaction parameters and the formation of the oxidation products have been investigated in detail. 57 references, 10 figures, 4 tables.« lessread more
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Journal ArticleDOI
Semiconductor-based Photocatalytic Hydrogen Generation
TL;DR: Approaches to Modifying the Electronic Band Structure for Visible-Light Harvesting and its Applications d0 Metal Oxide Photocatalysts 6518 4.4.1.
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Inorganic Materials as Catalysts for Photochemical Splitting of Water
TL;DR: A review of the known inorganic catalysts with a focus on structure-activity relationships is given in this article, where the first water splitting system based on TiO2 and Pt was proposed by Fujishima and Honda in 1972.
Journal ArticleDOI
Inorganic nanostructures for photoelectrochemical and photocatalytic water splitting
TL;DR: The current state of research on nanoscale-enhanced photoelectrodes and photocatalysts for the water splitting reaction with special emphasis of Fe(2)O(3) with an outlook on the challenges in solar fuel generation with nanoscales inorganic materials is reviewed.
Journal ArticleDOI
Engineering heterogeneous semiconductors for solar water splitting
TL;DR: In this paper, a critical review highlights some key factors influencing the efficiency of heterogeneous semiconductors for solar water splitting (i.e. improved charge separation and transfer, promoted optical absorption, optimized band gap position, lowered cost and toxicity, and enhanced stability and water splitting kinetics).
Journal ArticleDOI
Visible light induced photocatalytic degradation of organic pollutants
TL;DR: In this paper, the role of Fe(II)/Fe(III) species in the sensitization process of various substrates helping it in the process to photocatalytic degradation reactions of organic pollutants has been highlighted.
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