Hydrogen production from aqueous triethanolamine solution using Eosin Y-sensitized ZnO photocatalyst doped with platinum

Photocatalytic system for hydrogen production comprising ZnO as a photocatalyst, Eosin Y photo-sensitizer, triethanolamine electron donor and platinum co-catalyst is prepared and systematically tested under visible and simulated solar light irradiation. The results of laboratory experiments show that all studied parameters, such as a solution pH, Pt/ZnO dose, triethanolamine concentration and light intensity, notably influence the rate of photocatalytic hydrogen generation. The maximum hydrogen generation rate of 6.50 μmol min^?1 is achieved at pH 7.0 and 2 g L^?1 ZnO loaded with 0.75 wt% platinum, and 0.757 M triethanolamine concentration. The rate of hydrogen production as a function of triethanolamine concentration follows Langmuir-Hinshelwood kinetic model with reaction rate constant 4.50 μmol min^?1 and adsorption constant 14.84 M^?1 in solar light and 5.26 μmol min^?1 and 6.67 M^?1 in visible light, respectively. The reaction mechanism of hydrogen generation in the tested system is proposed and discussed.