Photocatalytic degradation of 1,4-dioxane and hydrogen production using liquid phase plasma on N- and Ni- codoped TiO₂ photocatalyst

A process of reducing 1,4-dioxane (DO) and producing hydrogen simultaneously was attempted through a photocatalytic decomposition in aqueous DO solution, known as a carcinogen, using liquid phase plasma (LPP) and photocatalyst. N- and Ni- codoped TiO₂ (N-Ni-TiO₂) was prepared as a photocatalyst sensitive to visible light. The prepared N-Ni-TiO₂ absorbed the light extended to the visible light region compared to TiO₂. The bandgap of the photocatalyst was about 2.4 eV. The photocatalyst doped with Ni ions showed the effect of greatly narrowing the bandgap. During the photocatalytic decomposition of DO, hydrogen was generated simultaneously with DO decomposition. In this reaction, N-Ni-TiO₂ showed better DO decomposition and hydrogen production efficiency than TiO₂ by irradiation of LPP emitting strong UV and visible light. This is because N-Ni-TiO₂ can cause photocatalytic reaction in both UV and visible light.