Facile Synthesis of Sulfur Doped Graphene Quantum Dots for High Performance Supercapacitor Applications

Abstract

A comprehensive study of an efficient pseudocapacitor electrode material has been done for sulfur doped graphene quantum dots (S-GQDs). Two different electrode materials were prepared by selecting two different sulfur containing powders that is, MgSO₄.7H₂O (sample-I), CuSO₄.7H₂O (sample-II), as source material by using the facile hydrothermal method. HRTEM results show that sample-II (∼5–20 nm) had a small size in comparison to sample-I (∼10–50 nm). The measured specific capacitance for sample-II was found to be 133 Fg⁻¹ at 0.1 mAg⁻¹ is much higher than in sample-II due to enhancement in electrical conductivity and improvement in the electron transfer between electrodes and electrolyte.

Keywords:

• Graphene quantum dots (GQDs)
• hydrothermal treatment
• magnesium sulfate
• copper sulfate
• specific capacitance
• electrical conductivity

Acknowledgments

This work was financially supported by Dr. D.S. Kothari Post-Doctoral Fellowship, University Grants Commission, of India. The author also would like to acknowledge Department of Science & Technology, New Delhi under Women Scientist Scheme A (WOS-A), for providing the financial support in favor of the reference no. of SR/WOS-A/PM-107/2017.