Investigating Ultrasonically Assisted Cd_xCr_yFe_{3 – (x + y)}O₄ for Its Electrochemical Efficacy towards Water Electrolysis, Ethanol and Methanol Oxidation

To increase the effectiveness of various electrochemical energy conversion and storage systems, electroactive and affordable electrocatalysts must be developed. Herein, the developed ultrasonic approach in the design and synthesis of the Fe-based spinel oxide (Fe₃O₄, CdFe₂O₄, CrFe₂O₄, and Cd_0.2Cr_0.8Fe₂O₄) nano-boxes, whose electrochemical performance was studied, is reported. The X-ray diffraction patterns proved the presence of the complete solitary-phase nano-spinel oxides. The Fourier-transform infrared spectra also supported the developed oxide structures. The thermogravimetric analysis showed a notable decline in the sample’s weights, with the most significant weight loss observed at approximately 35.46%. The cyclic voltammetry and the Tafel measurements were applied to investigate the electrochemical merits of the synthesized nanoparticles on a titanium supported electrode for different electrocatalytic applications. The results from cyclic voltammetry revealed that the substitution of the A site of the Fe atom with Cr or Cd had a detrimental impact on the current density value, and the ferrite with only chromium substitution exhibited the minimal current density at 0.7 V. The electrocatalytic activity estimated by Tafel curves towards an oxygen evolution reaction, ethanol and methanol oxidation reactions showed that the ternary ferrite with cadmium and chromium substitution (Cd_0.8Cr_0.2Fe₂O₄) had the highest current density of 0.224 mA/cm² at 850 mV towards an oxygen evolution reaction and was the most active towards a methanol oxidation reaction.