The oxygen evolution reaction (OER) is very sluggish compared to the hydrogen evolution reaction (HER). Considering this difference is essential when designing and developing a cost-effective and facile synthesis method for a catalyst that can effectively perform OER activity. The material should possess a high surface area and more active sites. Considering these points, in this work we successfully synthesized sheets of cobalt phosphate hydrate (CP) and sulphurated cobalt phosphate hydrate (CPS) material, using simple successive ionic layered adsorption and reaction (SILAR) methods followed by sulfurization. The CP and CPS electrodes exhibited overpotentials of 279 mV with a Tafel slope of 212 mV dec1 and 381 mV with a Tafel slope of 212 mV dec1, respectively. The superior performance after sulfurization is attributed to the intrinsic activity of the deposited well-aligned nanosheet structures, which provided a substantial number of electrochemically active surface sites, speeded electron transfer, and at the same time improved the diffusion of the electrolyte.

Abstract
1. Introduction
2. Experimental Method
    2.1. Synthesis of cobalt phosphate hydrate
3. Results and Discussion
    3.1. Structural and morphological characterization
    3.2. Electrochemical measurements
    3.3. Electrochemical activity towards OER
4. Conclusion
Acknowledgment
References

• Girish Kamble(Optoelectronic Convergence Research Center, Department of Materials Science and Engineering, Chonnam National University)
• Dhanaji Malavekar(Optoelectronic Convergence Research Center, Department of Materials Science and Engineering, Chonnam National University)
• Suyoung Jang(Optoelectronic Convergence Research Center, Department of Materials Science and Engineering, Chonnam National University)
• Jin Hyeok Kim(Optoelectronic Convergence Research Center, Department of Materials Science and Engineering, Chonnam National University) Corresponding author