An ultrasound-assisted approach to bio-derived nanoporous carbons: disclosing a linear relationship between effective micropores and capacitance

Abstract

There is a linear relationship between the effective micropore volume (surface area) and the specific capacitance of bio-derived nanoporous carbons, regardless of biomass type and activation temperature employed.

Renewable biomass‐derived carbons for electrochemical capacitor applications

“…BDC from mango skins provides a specific surface area of 2776 m 2 ·g –1 and micropore specific surface area of 1600 m 2 ·g –1 . The large micropore specific surface induces a maximum specific capacitance up to 493 F·g –1 and energy density of 27.5 Wh·kg –1 159 . Moreover, BDCs with dominant mesopores often exhibit excellent ions transmission performances because mesopores can serve as ions diffusion channels.…”

High-performance sono/nano-catalytic system: CTSN/Fe3O4–Cu nanocomposite, a promising heterogeneous catalyst for the synthesis of N-arylimidazoles

“…1,2 In recent decade, ultrasound wave (USW) irradiation has been introduced as one of the most effective strategies that can also be considered as a great co-catalyst agent for chemical reactions. 3,4 From both physical and chemical aspects, USW irradiation activates the catalytic sites of the chemicals to enhance the performance of the catalytic systems. Also, USW irradiation leads to obtain high reaction yields in short reaction times, with the least amount of the wasted materials.…”

Harnessing inherently hierarchical microstructures of plant biomass to construct three-dimensional nanoporous nitrogen-doped carbons as efficient and durable oxygen reduction electrocatalysts

“…The XRD patterns of NEA, NA and NE ( Fig. 3a) each present two weak and broad diffraction peaks: one is centred at 25.5 and the other at 43.7 is negligible and hardly observable, corresponding to the (002) and (100) diffraction planes of graphitic carbon, respectively, 18 whereas the XRD pattern of EA shows almost no diffraction peaks, proving the overwhelmingly amorphous feature and poor crystallinity of the four materials; furthermore, the high-intensity curves in the low-angle regions (10)(11)(12)(13)(14)(15) for NEA, NA, NE and EA suggest the existence of many micropores, 27 as discussed below. Moreover, the Raman analysis can be used to evaluate the defective degree of carbonaceous materials.…”

“…Micropores with width smaller than 0.7 nm, known as narrow micropores or ultramicropores, 28 are not easily accessible to K + and OH À as the hydrated diameters of these common electrolyte ions are between 0.6 and 0.7 nm, 29,30 thereby it becoming hard to form triple-phase boundaries that electrode is in contact with electrolyte and gas, where the ORR takes place. 31 Further, wide micropores of width >0.7 nm, termed as effective micropores, 13,20,27 permit the electrolyte ions to permeate through/into pores and to come into contact with the inner walls of pores, where reaction sites emerge. Specic surface areas and pore volumes of narrow micropores (width: <0.7 nm), effective micropores (width: 0.7-2 nm) and mesopores (width: 2-50 nm) of NEA, NA, NE and EA based on the DFT model are summarized in Table 1.…”