Catalyst-free solvothermal synthesis of ultrapure elemental N- and B-doped graphene for energy storage application

• Published in: Solid state ionics Vol. 353; p. 115371
• Main Authors: Bhushan, Rebti, Kumar, Prashant, Thakur, A.K.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.10.2020; Elsevier BV
• Subjects: Boron; Chemical fingerprinting; Chemical synthesis; Doping; Energy; Energy industry; Energy storage; Flux density; Graphene; Graphene doping; Heat transfer; Nitrogen; Photoelectrons; Pseudo-capacitive energy storage; Raman spectroscopy; Semiconductor doping; Solvothermal technique; Pseudo-capacitive energy storage; Solvothermal technique; Graphene doping
• ISSN: 0167-2738; 1872-7689
• DOI: 10.1016/j.ssi.2020.115371

Even though atomically thin graphene has excellent electronic mobility, is flexible and promptly removes unwanted heat from device interfaces, the wonder material is not yet been able to be employed in energy sector due to unavailability of electrochemically active sites. Doping graphene not only is expected to generate electrochemically active sites, will enhance inter-layer distance as a consequence of doping (up to 6 Å). On-demand tunable high level of doping of graphene is thus desirable to enable it for energy sector applications. While Raman spectroscopy of doped graphene attained via solvothermal method, attests to chemical fingerprints of doped graphene systems, X-ray photoelectron spectroscopy establishes that doping of graphene (as high as ~19.8%) by nitrogen and boron has been attained. While pristine as well as B-doped graphene exhibited EDLC behaviour, N doped graphene exhibited excellent signatures of pseudo-capacitive energy storage behaviour with energy density of 170 Wh/kg and power density as high as 8.3 kW/kg. Solvothermal technique of doping graphene being single step, facile and economic; seems to have great potential for pseudo-capacitive energy storage applications where scalable production of doped graphene is needed. Doped graphene synthesized via facile and scalable solvothermal technique was explored for their potential in pseudo-capacitive energy storage. [Display omitted] •Unprecedented doping of 19.8% by N and 11.7% by B synthesized via catalyst-free solvothermal process.•Salient attributes of the pressure catalyzed synthesis are (a) facile, (b) singlestep (c) economic, (d) scalable, (e) highly tunable and (f) efficient•While pristine graphene exhibited pure EDLC behaviour, heavily N-doped graphene exhibited a clear signature of pseudo-capacitive energy storage mechanism.•Adequate doping along with enhanced carrier density, can facilitate pseudocapacitive behaviour with higher ED as well as high PD (170 Wh/kg and 8.3 kW/kg).