Impact of Co:Fe cations composition in amorphous and mesoporous cobalt iron phosphate electrocatalysts synthesized by SILAR method on durable electrochemical water splitting

• Published in: International journal of hydrogen energy 2024-04, Vol.61, p.162-172
• Main Authors: Khalate, Suraj A., Kadam, Sujit A., Ma, Yuan-Ron, Kumbhar, Sambhaji S., Bhosale, Shraddha B., Patil, Vinod V., Parale, Vinayak G., Kulkarni, Sachin B., Lokhande, Chandrakant D., Park, Hyung-Ho, Patil, Umakant M.
• Format: Article
• Language: English
• Subjects: Amorphous thin film electrocatalyst; Cations composition variation; Electrochemical water splitting; SILAR method
• ISSN: 0360-3199; 1879-3487
• DOI: 10.1016/j.ijhydene.2024.02.259

Efficient and durable electrocatalysts are crucial for energy conversion devices that perform the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER). The structural and morphological characteristics of the electrocatalyst can significantly impact the HER/OER performance. Therefore, it is essential to develop a high-performing electrocatalyst with desired properties using a simple and cost-effective chemical process. So, herein, successive ionic layer adsorption and reaction (SILAR) deposited amorphous, hydrous cobalt iron phosphate (CFP) thin film electrocatalysts are implemented toward electrochemical water splitting. Moreover, in the present work, the molar proportions of cobalt and iron were streamlined to study their synergistic effect on electrochemical HER and OER performance. The electrode of best-performing (CFP–S2) requires the lowest overpotentials of 242 mV for OER and 67.9 mV for HER at a current density of 10 mA/cm2, which maintains its activity after 24 h. The alkaline water splitting into a similar electrolytic bath using two electrode systems was demonstrated for 100 h with the lowest overpotential of 1.72 V. The remarkable electrochemical performance and postmortem analysis unambiguously demonstrate that CFP electrodes are a highly promising and robust option for long-duration water-splitting devices, and the facile SILAR method for scalable CFP electrode synthesis indicates enormous potential for commercial applications. The facile chemical synthesis successive ionic layer adsorption and reaction (SILAR) method employed in this study yields promising results, highlighting the scalable binder-free synthesis and potential for durable electrochemical overall water splitting for clean fuel production. [Display omitted] •Novel synthesis of cobalt iron phosphate (CFP) by SILAR method.•Lower overpotentials for OER (242 mV) and HER (67.9 mV).•Overall water splitting with low potential (1.72 V).•Robustness of material for more than 100 h overall water splitting.•Lab-made device performance with the volume ratio 1:2 for O2 and H2 evolution.