Environmental issues such as global warming due to fossil fuel use are now major worldwide concerns, and interest in renewable and clean energy is growing. Of the various types of renewable energy, green hydrogen energy has recently attracted attention because of its eco-friendly and high-energy density. Electrochemical water splitting is considered a pollution-free means of producing clean hydrogen and oxygen and in large quantities. The development of non-noble electrocatalysts with low cost and high performance in water splitting has also attracted considerable attention. In this study, we successfully synthesized a NiCo2O4/NF electrode for an oxygen evolution reaction in alkaline water splitting using a hydrothermal method, which was followed by post-heat treatment. The effects of heat treatment on the electrochemical performance of the electrodes were evaluated under different heat-treatment conditions. The optimized NCO/NF-300 electrode showed an overpotential of 416 mV at a high current density of 50 mA/cm2 and a low Tafel slope (49.06 mV dec-1). It also showed excellent stability (due to the large surface area) and the lowest charge transfer resistance (12.59 Ω). The results suggested that our noble-metal free electrodes have great potential for use in developing alkaline electrolysis systems.

Abstract
1. 서 론
2. 실험방법
3. 결과 및 고찰
4. 결 론
감사의 글
References

• 권민솔(충북대학교 도시·에너지·환경 융합학부) | Minsol Kwon (Department of Urban, Energy, and Environmental Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Chungbuk 28644, Republic of Korea)
• 고재성(충북대학교 신소재공학과) | Jaeseong Go (Department of Advanced Materials Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Chungbuk 28644, Republic of Korea)
• 이예솔(충북대학교 신소재공학과) | Yesol Lee (Department of Advanced Materials Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Chungbuk 28644, Republic of Korea)
• 이성민(충북대학교 신소재공학과) | Sungmin Lee (Department of Advanced Materials Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Chungbuk 28644, Republic of Korea)
• 유지수(충북대학교 신소재공학과) | Jisu Yu (Department of Advanced Materials Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Chungbuk 28644, Republic of Korea)
• 이효원(충북대학교 신소재공학과) | Hyowon Lee (Department of Advanced Materials Engineering, Chungbuk National University, Chungdae-ro 1, Seowon-Gu, Cheongju, Chungbuk 28644, Republic of Korea)
• 송성호(공주대학교 신소재공학부) | Sung Ho Song (Division of Advanced Materials Engineering, Kongju National University, Chungnam 330-717, Cheonan-si, Republic of Korea) Corresponding author
• 이동주(충북대학교 도시·에너지·환경 융합학부, 충북대학교 신소재공학과) | Dongju Lee (Department of Urban, Energy, and Environmental Engineering, Chungbuk National University,Department of Advanced Materials Engineering, Chungbuk National University) Corresponding author