Zinc iron selenide nanoflowers anchored g-C₃N₄ as advanced catalyst for photocatalytic water splitting and dye degradation

Hydrogen has been considered as a promising clean energy source owing to its renewability and zero carbon emission. Accordingly, photocatalytic water splitting has drawn much attention as a key green technology of producing hydrogen. However, it has remained as a great challenge due to the low production rate and expensive constituents of photocatalytic systems. Herein, we synthesised nanostructures consisting of transition metal selenide and g-C₃N₄ for photocatalytic water splitting reaction. They include ZnSe, FeSe₂, Zn/FeSe₂ and ZnFeSe₂ nanoflowers and a nanocomposite made of Zn/FeSe₂ and g-C₃N₄. Hydrogen evolution rates in the presence of ZnSe, FeSe₂, Zn/FeSe₂ and ZnFeSe₂ photocatalysts were measured as 60.03, 128.02, 155.11 and 83.59 μmolg⁻¹ min⁻¹, respectively. On the other hand, with the nanocomposite consisting of Zn/FeSe₂ and g-C₃N₄, the hydrogen and oxygen evolution rates were significantly enhanced up to 202.94 μmol g⁻¹min⁻¹ and 90.92 μmol g⁻¹min⁻¹, respectively. The nanocomposite was also examined as a photocatalyst for degradation of rhodamine B showing that it photodegrades the compound two times faster compared to pristine Zn/FeSe₂ nanoflowers without g-C₃N_4. Our study suggests the nanocomposite of Zn/FeSe₂ and g-C₃N₄ as a promising photocatalyst for energy and environmental applications.