Photochemical hydrogen production with cadmium sulfide suspensions

Journal Article · Thu Jul 19 04:00:00 EDT 1984 · J. Phys. Chem.; (United States)

DOI:https://doi.org/10.1021/j150659a025· OSTI ID:5963548

Buehler, N; Meier, K; Reber, J F

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. After 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.

• Research Organization: Central Research Labs., Basel, Switzerland
• OSTI ID: 5963548
• Journal Information: J. Phys. Chem.; (United States), Journal Name: J. Phys. Chem.; (United States) Vol. 88:15; ISSN JPCHA
• Country of Publication: United States
• Language: English

Related Subjects

08 HYDROGEN
080106* -- Hydrogen-- Production-- Biosynthesis & Photochemical Processes
ALKALI METAL COMPOUNDS
CADMIUM COMPOUNDS
CADMIUM SULFIDES
CATALYSIS
CATALYSTS
CATALYTIC EFFECTS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
CHEMICAL REACTIONS
CHEMISTRY
DATA
DISPERSIONS
ELECTROLYTES
ELEMENTS
EMISSION SPECTROSCOPY
EXPERIMENTAL DATA
FLUORESCENCE SPECTROSCOPY
HYDROGEN
HYDROGEN COMPOUNDS
HYDROGEN PRODUCTION
HYPOPHOSPHOROUS ACID
INFORMATION
INORGANIC ACIDS
INORGANIC PHOSPHORS
KINETICS
MEDIUM TEMPERATURE
METALS
MIXTURES
NONMETALS
NUMERICAL DATA
OXYGEN COMPOUNDS
PHOSPHORS
PHOTOCHEMICAL REACTIONS
PHOTOCHEMISTRY
PLATINUM
PLATINUM METALS
REACTION KINETICS
SODIUM COMPOUNDS
SODIUM SULFATES
SOLUTIONS
SPECTRA
SPECTROSCOPY
SULFATES
SULFIDES
SULFITES
SULFUR
SULFUR COMPOUNDS
TRANSITION ELEMENTS
ULTRAVIOLET SPECTRA