N/P Codoped Porous Carbon/One-Dimensional Hollow Tubular Carbon Heterojunction from Biomass Inherent Structure for Supercapacitors

Abstract

A N/P codoped porous carbon/one-dimensional (1D) hollow tubular carbon heterojunction was successfully fabricated from waste biomass. 1D carbon microtube (CMT) originating from the inherent biological structure of enteromorpha prolifera (EP) was used for constructing the heterojunction with uniform heteroatom distribution and good conductivity by pyrolyzing the chitosan dihydrogen phosphate protic salt (CDPPS)-coated CMT, in which CMT was used as conductive substrate and CDPPS as carbon, nitrogen, phosphorus sources, and "soft" activating agent. The optimized heterojunction (NPEPC-6-900) possesses a large specific surface area (1220 m 2 g −1 ) and high content of heteroatom functionalities (4.50 at. % N and 2.36 at. % P). A similar effect also occurs on cotton with analogous 1D hollow tubular architecture structure, and the sample presents a specific surface area (766 m 2 g −1 ) and chemical composition (3.75 at. % N and 1.34 at. % P). Benefiting from the distinctive structural feature and desirable heteroatom doping, the NPEPC-6-900-based electrode indicates high capacitance of 324 F g −1 at 1 A g −1 , and still maintains the capacitance of 231 F g −1 even at 20 A g −1 (ca. 71.3% capacitance retention). Moreover, it also possesses good cycling stability with only a loss of 2% after 5000 cycles.

Renewable biomass‐derived carbons for electrochemical capacitor applications

“…In most cases, BDCs may inherit or evolve the special structures of biomass precursors. The diversity of biomass leads to the formation of BDCs with spherical, 44,45 fibrous, 46,47 sheet‐like, 48,49 and skeleton structure 50–53 . Biomass, especially lignocellulosic biomass, consists of mainly cellulose, hemicellulose, and lignin (Figure 3), 54–56 chemically composed of C, H, and O with the partial presence of N, S, and P, as well as a trace of Fe, Ca, K, Si, and other elements.…”

“…Meanwhile, the rich pores in tubular carbon walls further increase the specific surface area for ions storage, as well as provide fast ions transport channels. Some biomass, such as enteromorpha prolifera, 47 cotton, 93 kapok fibers, 217,218 and coconut fibers, 53 possesses natural hollow tubular structure that can easily be converted into hollow tubular BDCs. For instance, BDCs from kapok fibers have tubular structures and N‐containing sandwich‐like walls, promoting ions transport.…”

Biomass Straw-Derived Porous Carbon Synthesized for Supercapacitor by Ball Milling

“…The electrochemical impedance spectroscopy (EIS) was carried out over the frequency range from 0.01 Hz to 100 kHz to further explore the electrochemical properties of TCZn-X samples. Figure 5 d displays the Nyquist plots of all samples, which can be divided in two distinct parts, the low frequency (R s ) and the high frequency (R ct : charge transfer resistance), respectively [ 51 ]. At low frequency, the more vertical the plots slope, the faster the diffusion of ions, which would result in a higher conduction performance [ 52 ].…”

One‐Pot Synthesis of Sulfur and Nitrogen Co‐Functionalized Graphene Material using Deep Eutectic Solvents for Supercapacitors

“…Generally,DESs show comparable physicochemical properties to the traditionally used ionic liquids(ILs). [24] Liang et al used porouso rganic polymers (POPs)a sc arbon sourcet op roduce carbon materials for energy storage. In addition, DESs are expected to be less toxic and have better biocompatibility than ILs.…”

“…Li et al produced aN /P co-doped porous carbon/1 Dh ollow tubular carbon heterojunction through the pyrolyzation of the chitosan dihydrogen phosphate protic salt as C, N, and Ps ources. [24] Liang et al used porouso rganic polymers (POPs)a sc arbon sourcet op roduce carbon materials for energy storage. [25] Sun et al developed an IL to produce Na nd Ag reen approacht ot he synthesis of sulfur and nitrogen cofunctionalized reduced graphene oxide (SN-rGO) is presented; it involves the reduction of graphene oxide (GO) using ad eep eutectics olvent (DES) as chemical reducing agent andd opant.…”