Designing a Rare DNA-Like Double Helical Microfiber Superstructure via Self-Assembly of In Situ Carbon Fiber-Encapsulated WO3- x Nanorods as an Advanced Supercapacitor Material

Akshay V Salkar; Amarja P Naik; Sheshanath V Bhosale; Pranay P Morajkar

doi:10.1021/acsami.0c21105

Designing a Rare DNA-Like Double Helical Microfiber Superstructure via Self-Assembly of In Situ Carbon Fiber-Encapsulated WO_{3- x} Nanorods as an Advanced Supercapacitor Material

ACS Appl Mater Interfaces. 2021 Jan 13;13(1):1288-1300. doi: 10.1021/acsami.0c21105. Epub 2020 Dec 24.

Authors

Akshay V Salkar¹, Amarja P Naik¹, Sheshanath V Bhosale¹, Pranay P Morajkar¹

Affiliation

¹ School of Chemical Sciences, Goa University, Taleigao Plateau, 403206 Goa, India.

PMID: 33356091
DOI: 10.1021/acsami.0c21105

Abstract

Double helical DNA structure is one of the most beautiful and fascinating nanoarchitecture nature has produced. Mimicking nature's design by the tailored synthesis of semiconductor nanomaterials such as WO₃ into a DNA-like double helical superstructure could impart special properties, such as enhanced stability, electrical conductivity, information storage, signal processing, and catalysis, owing to the synergistic interaction across helices. However, double helical WO₃ synthesis is extremely challenging and has never been reported earlier. This investigation presents the first-ever report on a facile synthesis route for designing a DNA-like double helical WO_3-x/C microfiber superstructure via self-assembly of in situ carbon fiber-encapsulated WO_3-x nanorods. This innovative design strategy is completely template-free and does not require predesigned helical templates or hydro/solvothermal treatment. Detailed spectroscopic material characterization and electrochemical studies confirmed that the double helical structure with carbon fiber-WO_3-x heterostructures enabled effective induction and distribution of oxygen vacancies along with W⁵⁺/W⁶⁺ redox surface states. Furthermore, faster electrode-electrolyte interfacial kinetics, improved electrical conductivity, and cycling stability has been observed in the carbon fiber-WO_3-x heterostructures which resulted in a high area specific capacitance of 401 mF cm^-2 at 2 mA cm^-2 with excellent capacitance retention of >94% for more than 5000 cycles. Additionally, the carbon fiber-WO_3-x heterostructures demonstrated promising performance when fabricated in a solid-state asymmetric supercapacitor device with the power density of 498 W kg^-1 at an energy density of 15.4 W h kg^-1. Therefore, the rare DNA-like double helical WO_3-x/C superstructure synthesized in this study could open new doorways toward in situ, facile fabrication of double helical superstructures for energy and environmental applications.

Keywords: DNA-like superstructures; WO3−x nanorods; asymmetric supercapacitor; charge−discharge; mechanism; self-assembly.