DFT Study on the Role of Oxygen Vacancies in the Structural and Electronic Properties of Spinel NiCo2O4

Authors

  • Nurzaihani Batrisyia Said Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Malaysia
  • Nur Hamizah Mohd Zaki Ionic Material& Devices (iMADE) Research Laboratory, Institute of Science (IOS), Universiti Teknologi MARA, 40450 Shah Alam, Malaysia
  • Nursyahirah Nordin Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Malaysia
  • Fatin Nabilah Sazman Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Malaysia
  • Nur Amirah Syafiqah Amirul Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Malaysia
  • Nafisha Balqis Khairuddin Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Malaysia
  • Ainnur-Sherene Kamisan Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Malaysia
  • Oskar Hasdinor Hassan Ionic Material& Devices (iMADE) Research Laboratory, Institute of Science (IOS), Universiti Teknologi MARA, 40450 Shah Alam, Malaysia
  • Mohamad Fariz Mohamad Taib Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Malaysia
  • Muhd Zu Azhan Yahya Faculty of Defence Science & Technology, Universiti Pertahanan Nasional Malaysia, 57100 Kuala Lumpur, Malaysia

DOI:

https://doi.org/10.24191/scl.v20i2.9447

Keywords:

Structural, Band gap, Supercapacitor, CASTEP, Nickel cobaltite

Abstract

NiCo₂O₄ (NCO) has been widely studied as an electrode material for supercapacitors due to its good redox properties and conductivity. In this study, the effects of oxygen vacancies on the structural and electronic properties of NCO were investigated using density functional theory (DFT). An oxygen atom was removed from the structure to create a vacancy, which caused slight lattice expansion and local distortion. These changes were mainly due to the reduction of Co3+ to Co2+. The formation energy was calculated as 4.43eV, showing that the vacancy can form under suitable conditions. A decrease in band gap from 1.158eV to 0.746eV was observed, indicating improved conductivity. From the density of states, more Co 3d states and fewer O 2p states were found near the Fermi level. This suggests that charge transport can be enhanced by the presence of oxygen vacancies. Overall, the performance of NCO as a supercapacitor electrode can be improved by introducing oxygen vacancies.

 

Author Biographies

  • Nurzaihani Batrisyia Said, Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Malaysia

    Nurzaihani Batrisyia binti Said holds a Bachelor of Science (Hons) in Physics and is currently a Master candidate in Physics at Universiti Teknologi MARA, Malaysia. Her research focuses on electrode materials for supercapacitors, particularly investigating the structural and electronic properties of transition-metal oxides to enhance energy storage performance. She can be reached via email at nurzaihanibatrisyia@uitm.edu.my.

  • Nur Hamizah Mohd Zaki, Ionic Material& Devices (iMADE) Research Laboratory, Institute of Science (IOS), Universiti Teknologi MARA, 40450 Shah Alam, Malaysia

    Nur Hamizah binti Mohd Zaki is a senior lecturer at Faculty of Applied Science and a researcher of Ionic Material and Devices (IMADE) at Universiti Teknlogi MARA. He holds a Doctor of Philosophy in Material Physics from Universiti Teknologi MARA. His research focuses on Computational Materials Science (First Principles), Oxide materials, energy storage studies, such as supercapacitor. She can be contacted at hamizahzaki@uitm.edu.my

  • Nursyahirah Nordin, Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Malaysia

    Nursyahirah binti Nordin holds a Bachelor of Science (Hons) in Education Physics and is currently a Master candidate in Physics at Universiti Teknologi MARA, Malaysia. Her research focuses on electrode materials for battery, particularly investigating the structural and electronic properties to enhance energy storage performance. She can be reached via email nursyahirahnor1001@gmail.com.

  • Fatin Nabilah Sazman, Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Malaysia

    Fatin Nabilah binti Sazman holds a Master of Science (Hons) in Physics and is currently a PhD. candidate in Physics at Universiti Teknologi MARA, Malaysia. Her research focuses on electrode materials for battery, particularly investigating the structural and electronic properties to enhance energy storage performance. She can be reached via email fatinsazman29@gmail.com

  • Nur Amirah Syafiqah Amirul, Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Malaysia

    Nur Amirah Syafiqah binti Amirul holds a Bachelor of Science (Hons) in Physics and is currently a PhD. candidate in Physics at Universiti Teknologi MARA, Malaysia. Her research focuses on materials for solar panel, particularly investigating the structural electronic and optical properties to enhance energy storage performance. She can be reached via email nuramirahsyafiqahamirul@gmail.com

  • Nafisha Balqis Khairuddin, Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Malaysia

    Nafisha Balqis bin Khairuddin holds a Bachelor of Science (Hons) in Physics and is currently Master candidate in Physics at Universiti Teknologi MARA, Malaysia. Her research focuses on materials for solar panel, particularly investigating the structural electronic and optical properties to enhance energy storage performance. She can be reached via email nafishablqs@gmail.com

  • Ainnur-Sherene Kamisan, Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Malaysia

    Ainnur-Sherene Kamisan is a senior lecturer at Faculty of Applied Science and a researcher of Ionic Material and Devices (IMADE) at Universiti Teknlogi MARA. He holds a Doctor of Philosophy in Material Physics from Universiti Teknologi MARA. His research focuses on Computational Materials Science (First Principles), Oxide materials, nanogenerator studies, Nano Technology (CNT, Graphene), and Solar Cell. He can be contacted at ainnur@uitm.edu.my

  • Oskar Hasdinor Hassan, Ionic Material& Devices (iMADE) Research Laboratory, Institute of Science (IOS), Universiti Teknologi MARA, 40450 Shah Alam, Malaysia

    Oskar Hasdinor Hassan is a professor at College of Creative Arts and currently the Director of Institute of Science at Universiti Teknlogi MARA. He holds a Doctor of Philosophy in Design Manufacturing from Ruhr-University Bochum, W. Germany and Professional Technologist in Material Science Technology (N/P:PT19030109). His research focuses on Renewable Energy (focus on Nanogenerator Technology), Design and Technology, Ceramics battery and super-capacitor, Solid Oxide Fuel Cells and computational materials. He can be contacted at oskar@uitm.edu.my

  • Mohamad Fariz Mohamad Taib , Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam, Malaysia

    Mohamad Fariz Mohamad Taib is an associate professor at Faculty of Applied Science and currently the Lead Researcher of Ionic Material and Devices (IMADE) at Universiti Teknlogi MARA. He holds a Doctor of Philosophy in Computational Physics from Universiti Teknologi MARA. His research focuses on Computational Materials Science (First Principles and Ab-Initio) of Ferroelectric, Multiferroic, Batteries (Lithium cathode material), Nano Technology (CNT, Graphene), Heusler Alloy, Sensors, Solar Cell and Superconductor. He can be contacted at mfariz@uitm.edu.my

  • Muhd Zu Azhan Yahya, Faculty of Defence Science & Technology, Universiti Pertahanan Nasional Malaysia, 57100 Kuala Lumpur, Malaysia

    Prof. Ts. Dr. Muhd Zu Azhan bin Yahya is a Professor of Physics (Materials Science) in the Department of Defence Science, Faculty of Defence Science & Technology at the National Defence University of Malaysia (UPNM). He holds a PhD in Advanced Materials from the University of Malaya. A well-known figure in the field of advanced materials, his research primarily focuses on energy technology, including batteries, supercapacitors, and solar cells. His work encompasses both experimental and computational methods. He can be contacted mzay@upnm.edu.my

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Published

2026-06-30

Issue

Vol. 20 No. 2 (2026): Volume 20, Issue 2, June 2026

Section

Articles

License

Copyright (c) 2026 Nurzaihani Batrisyia Said, Nur Hamizah Mohd Zaki, Nursyahirah Nordin, Fatin Nabilah Sazman, Nur Amirah Syafiqah Amirul, Nafisha Balqis Khairuddin, Ainnur-Sherene Kamisan, Oskar Hasdinor Hassan, Mohamad Fariz Mohamad Taib , Muhd Zu Azhan Yahya

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