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-C3N4. Our study suggests the nanocomposite of Zn/FeSe2 and g-C3N4 as a promising photocatalyst for energy and environmental applications.