The Effect of Cu and Ga Doped ZnIn₂S₄ under Visible Light on the High Generation of H₂ Production

• Main Authors: Ikki Tateishi, Mai Furukawa, Hideyuki Katsumata, Satoshi Kaneco
• Format: Article
• Language: English
• Published: MDPI AG 2019-09-01
• Series: ChemEngineering
• Subjects: photocatalytic hydrogen generation; copper; gallium; znin₂s₄
• Online Access: https://www.mdpi.com/2305-7084/3/4/79

A Cu⁺ and Ga³⁺ co-doped ZnIn₂S₄ photocatalyst (Zn_(1−2x)(CuGa)_xIn₂S₄) with controlled band gap was prepared via a simple one-step solvothermal method. Zn_(1−2x)(CuGa)_xIn₂S₄ acted as an efficient photocatalyst for H₂ evolution under visible light irradiation (λ > 420 nm; 4500 µW/cm²). The effects of the (Cu and Ga)/Zn molar ratios of Zn_(1−2x)(CuGa)_xIn₂S₄ on the crystal structure (hexagonal structure), morphology (microsphere-like flower), optical property (light harvesting activity and charge hole separation ability), and photocatalytic activity have been investigated in detail. The maximum H₂ evolution rate (1650 µmol·h^−1·g^−1) was achieved over Zn_0.84(CuGa)_0.13In₂S₄, showing a 3.3 times higher rate than that of untreated ZnIn₂S₄. The bandgap energy of Zn_(1−2x)(CuGa)_xIn₂S₄ decreased from 2.67 to 1.90 eV as the amount of doping Cu⁺ and Ga³⁺ increased.