Photocatalytic Hydrogen Production by RGO/ZnIn₂S₄ under Visible Light with Simultaneous Organic Amine Degradation

In this work, the study of photocatalytic hydrogen production by RGO/ZnIn₂S₄ with simultaneous degradation of organic amines was carried out in the presence of organic amines in wastewater as the sacrificial agents. The effects of several factors, such as organic amine types, pH value, catalyst concentration, organic amine concentration, and sunlight source, on the photocatalytic activity of RGO/ZnIn₂S₄ for H₂ production were investigated. At the same time, its performance of degrading organic amines during H₂ production was also examined. The results showed that the order of H₂ production activity of RGO/ZnIn₂S₄ in six organic amine solutions was N(CH₂CH₃)₃ > N(HOCH₂CH₂)₃ > N(CH₃)₃ > HO(CH₂)₂NH₂ > C₆H₅-N₂> CO(NH₂)₂, and the highest H₂ production was in N(CH₂CH₃)₃ (triethylamine) solution, being 1597 μmol·g^-1·h^-1, which is 2.6 times as high as that using the aqueous solution mixture of Na₂S and Na₂SO₃ as the sacrificial agent. In addition, when the pH was 13, the catalyst concentration was 1.0 g·L^-1, and the triethylamine concentration was 1.0 mol·L^-1, the photocatalytic activity was the highest. Furthermore, the relationship between triethylamine concentration and H₂ production was analyzed according to the theory of dynamics.