Chandu Venkata Veera Muralee Gopi is a Ph.D student of Department of Electrical Engineering at Pusan National University, Busan, South Korea. His current scientific interests focus on design, synthesis and application of nanomaterials for applications in energy conversion/storage. He has published over 43 papers and his works have been cited over 318 times.
Carbon nanotubes (CNT) and metal sulfides have attracted considerable attention owing to their outstanding properties and multiple application areas, such as electrochemical energy conversion and energy storage. Here we describes a cost-effective and facile solution approach to the preparation of metal sulfides (PbS, CuS, CoS, and NiS) grown directly on CNTs, such as CNT/PbS, CNT/CuS, CNT/CoS, and CNT/NiS flexible electrodes for quantum dot-sensitized solar cells (QDSSCs) and supercapacitors (SCs). X-ray photoelectron spectroscopy, X-ray diffraction, and transmission electron microscopy confirmed that the CNT network was covered with high-purity metal sulfide compounds. QDSSCs equipped with the CNT/NiS counter electrode (CE) showed an impressive energy conversion efficiency (η) of 6.41% and remarkable stability. Interestingly, the assembled symmetric CNT/NiS-based polysulfide SC device exhibited a maximal energy density of 35.39 W h kg-1 and superior cycling durability with 98.39% retention after 1,000 cycles compared to the other CNT/metal-sulfides. The elevated performance of the composites was attributed mainly to the good conductivity, high surface area with mesoporous structures and stability of the CNTs and the high electrocatalytic activity of the metal sulfides. Overall, the designed composite CNT/metal-sulfide electrodes offer an important guideline for the development of next level energy conversion and energy storage devices.
Audience Take away:
The energy crisis and global warming concerns have increasing the demand for progress into high performance energy conversion and energy storage devices. The development of new electrode materials for energy conversion and energy storage technologies, particularly quantum-dot-sensitized solar cells (QDSSCs) and supercapacitors (SCs) have attracted special attention.
To date, there have been many reports on individual CNTs and metal chalcogenides used as electrode materials in both QDSSCs and SCs. None of these studies, however, examined composite CNT/metal sulfides as efficient electrode for high-performance QDSSCs and SCs. Therefore, the combination of CNTs with metal sulfides has been proposed to enhance the electrocatalytic activity and conductivity of CEs.
Overall, these results indicate that the CNT/metal-sulfide composites provide a new path for the development of similar advanced electrochemical electrode materials for a range of applications. Fourth, the flexible property of the supercapacitor is highly desired for actual applications.