MASS-SPECTROMETRY QUANTIFICATION OF HYDROGEN PRODUCED UNDER ILLUMINATION OF P-CUINSE2 AND MODIFIED SURFACES

Hydrogen gas obtained from illuminated p-CuInSe2 (CIS) on 0.5 M sulfur ic acid solution was collected in a glass balloon using argon as carri er gas, and quantified with a mass spectrometer. p-CuInSe, thin films were electrodeposited on SnO2-coated glass plates, according to refere nces already reported. Electrochemical deposition of Se and chemical m odifications on the semiconducting surfaces with adsorbed ruthenium we re also tested for the hydrogen evolution reaction. The E-g and E-tb o f the modified p-CuInSe2 were determined. Atomic absorption spectromet ry was used to quantify the chemical compositions of the semiconductor s before and after the illumination. The modified semiconductors had a composition of CIS/Se-24 and CIS/Se-6/(RuO4)(0.12), under illuminatio n at 0.8V in 0.5 M H2SO4 for 4 min, the volumes of evolved hydrogen we re 1 cm(3) and 2.4 cm(3), respectively. (C) 1997 International Associa tion for Hydrogen Energy.