Sacrificial hydrogen generation from aqueous triethanolamine with Eosin Y-sensitized Pt/TiO2 photocatalyst in UV, visible and solar light irradiation

• Sacrificial H2 generation in 1 sun is studied with Pt loaded EY-sensitized TiO2.
• H2 generation reaction mechanism in UV, visible and solar light is established.
• In both solar and visible light HCHO is detected as an intermediate.
• H2 generation kinetics follows a Langmuir-type isotherm.
• At lower intensity, QYs were much higher due to insignificant charge recombination.

In this paper, we have studied Eosin Y-sensitized sacrificial hydrogen generation with triethanolamine as electron donor in UV, visible, and solar light irradiation. Aeroxide TiO2 was loaded with platinum metal via solar photo-deposition method to reduce the electron hole recombination process. Photocatalytic sacrificial hydrogen generation was influenced by several factors such as platinum loading (wt%) on TiO2, solution pH, Eosin Y to Pt/TiO2 mass ratio, triethanolamine concentration, and light (UV, visible and solar) intensities. Detailed reaction mechanisms in visible and solar light irradiation were established. Oxidation of triethanolamine and formaldehyde formation was correlated with hydrogen generation in both visible and solar lights. Hydrogen generation kinetics followed a Langmuir-type isotherm with reaction rate constant and adsorption constant of 6.77 × 10−6 mol min−1 and 14.45 M−1, respectively. Sacrificial hydrogen generation and charge recombination processes were studied as a function of light intensities. Apparent quantum yields (QYs) were compared for UV, visible, and solar light at four different light intensities. Highest QYs were attained at lower light intensity because of trivial charge recombination. At 30 mW cm−2 we achieved QYs of 10.82%, 12.23% and 11.33% in UV, visible and solar light respectively.

Figure optionsDownload as PowerPoint slide