Superior Multifunctional Activity of Nanoporous Carbons with Widely Tunable Porosity: Enhanced Storage Capacities for Carbon‐Dioxide, Hydrogen, Water, and Electric Charge
Srinivas Gadipelli, Christopher A. Howard, Jian Guo, Neal T. Skipper, Hong Zhang, Paul R. Shearing, Dan J. L. Brett
Abstract
Abstract Nanoporous carbons (NPCs) with engineered specific pore sizes and sufficiently high porosities (both specific surface area and pore volume) are necessary for storing energy in the form of electric charges and molecules. Herein, NPCs, derived from biomass pine‐cones, coffee‐grounds, graphene‐oxide and metal‐organic frameworks, with systematically increased pore width (<1.0 nm to a few nm), micropore volume (0.2–0.9 cm 3 g −1 ) and specific surface area (800–2800 m 2 g −1 ) are presented. Superior CO 2 , H 2, and H 2 O uptakes of 35.0 wt% (≈7.9 mmol g −1 at 273 K), 3.0 wt% (at 77 K) and 85.0 wt% (at 298 K), respectively at 1 bar, are achieved. At controlled microporosity, supercapacitors deliver impressive performance with a capacity of 320 and 230 F g −1 at 500 mA g −1 , in aqueous and organic electrolytes, respectively. Excellent areal capacitance and energy density (>50 Wh kg −1 at high power density, 1000 W kg −1 ) are achieved to form the highest reported values among the range of carbons in the literature. The noteworthy energy storage performance of the NPCs for all five cases (CO 2 , H 2 , H 2 O, and capacitance in aqueous and organic electrolytes) is highlighted by direct comparison to numerous existing porous solids. A further analysis on the specific pore type governed physisorption capacities is presented.