Boosting green hydrogen generation using Zn-substituted CoFe₂O₄ catalysts prepared by sol-gel technique for water...

Hydrogen has the potential to become a suitable alternative to the non-renewable sources like fossil fuels. The higher calorific values and ease of storage makes it better alternative to other renewable sources of energy. But the limiting factor for the usage of hydrogen is its inefficient production. To overcome this drawback, in our current work, we have developed a class of Zn substituted cobalt nanoferrites as a catalyst for producing the green and sustainable hydrogen energy. The cobalt nano catalysts are prepared through sol-gel auto-combustion (SA) method. A spinel phase is observed for the fabricated catalysts. Spherical shaped grains are found in the FESEM images of CoF1 and CoF3 catalysts. With Zn substitution, the band gap is found to vary between 1.69 to 1.91 eV which helps in the catalytic property of prepared catalysts. XPS investigation shows oxidation states of Zn, Co, Fe, and O. The magnetic measurements confirms that the introduction of dopant causes a decrease in coercivity while maintaining the saturation magnetisation, which helps in the recoverability of catalysis during the procedure. Zn_0.06Co_0.94Fe₂O₄ (x = 0.06) catalyst shows maximum photocatalytic hydrogen production of 21.51 mmol[Formula: see text], with a Tafel slope of 141.88 mV/dec. Thus, the study provides the cost-effective alternative to traditionally use the catalysts which are not economically efficient for the sustainable and green H₂ generation.