High performance Sm substituted Ni-Zn catalysts for green hydrogen generation via Photo/Electro catalytic water splitting processes

In this work, samarium doped Ni-Zn catalysts with a composition of Ni_0.9Zn_0.1Sm_yFe_2-yO₄ (y = 0–0.03) are made by inorganic sol–gel auto-combustion (SC) route. These Ni-Zn materials depict the forming of typical cubic crystal structure (Fd3m) and it is affirmed by the X-ray diffraction plots. The existence of cubic, spherical, and aggregated shaped grains with an average grain size that falls in between the range of 188 to 316 nm are confirmed from the FESEM images of prepared materials. According to the photo catalytic water splitting research findings, the total hydrogen yield for the Ni-Zn1, Ni-Zn2, Ni-Zn3, and Ni-Zn4 catalysts after four hours are 16.17, 15.02, 23.47 and 24.99 mmol $g_{cat}^{-1}$. Among all the compositions, the Ni-Zn4 photocatalyst exhibits the maximum photocatalytic performance of 24.99 mmol $g_{cat}^{-1}$. However, the Ni-Zn4 sample also shows the high electro catalytic hydrogen evolution reaction (HER) performance. With their outstanding photo/electro performance, the synthesized Sm-doped Ni-Zn nanoferrites shows great promise as potential candidates for the green hydrogen generation.