In situ self‐template synthesis of cobalt/nitrogen‐doped nanocarbons with controllable shapes for oxygen reduction reaction and supercapacitors

Abstract

Summary Shape‐controlled Co/N‐doped nanocarbons derived from polyacrylonitrile (PAN) were synthesized by a one‐step in situ self‐template method followed by a pyrolysis procedure. This is the first study to tune the nanostructure of Co/N‐doped carbon materials by providing a metal salt as the template and additive. The moderate surface area (699.47 m2 g−1), highly developed pore structure, homogenous Co and N doping and designed “egg‐box” structure impart Co/N‐doped cross‐linked porous carbon (Co/N‐CLPC) with excellent electrocatalytic activity and capacitive performance. This material displayed an onset potential of 0.805 V (vs RHE), a current density of −5.102 mA cm−2, excellent long‐term durability, and good resistance to methanol crossover, which are comparable with the characteristics of a commercial 20‐wt% Pt/C catalyst. In addition, Co/N‐CLPC demonstrated a high specific capacitance of 313 F g−1 at 0.5 A g−1, notable rate performance of 63% at 50 A g−1, and good cycling stability of 104.8% retention after 5000 cycles when used as a supercapacitor electrode. This method enables new routes to obtaining Co/N‐doped nanocarbons with shape‐controlled structures for energy conversion and storage applications.

Boosting the energy storage performance of cobalt molybdate microspheres constructed from urotropin‐induced ultrathin nanosheets

“…In Figure 9A, the similar rectangle shape of all the CV curves reflects the energy storage mechanism of reversible electrochemical double layers. 43 This fact can also be proved by the symmetric and linear GCD curves ( Figure 9B). In Figure 9C, the specific capacitances of the AC are 361, 272, 244, 196, and 178 F/g at 0.50, 0.75, 1.00, 2.00, and 2.50 A/g, respectively, based on Equation (2).…”

“…Before the assembly, the supercapacitor behaviors of AC should be measured to balance the charge of two electrodes. In Figure A, the similar rectangle shape of all the CV curves reflects the energy storage mechanism of reversible electrochemical double layers . This fact can also be proved by the symmetric and linear GCD curves (Figure B).…”

High‐performance activated carbons for electrochemical double layer capacitors: Effects of morphology and porous structures

“…23 Currently, the most widely used electrode materials in EDLCs are activated carbons (ACs), which generally possess high surface area, good electric conductivity, and excellent long-term cycling stability. 22,[24][25][26] Heteroatoms doping [27][28][29][30][31] or co-doping [32][33][34][35] can effectively improve the energy storage of ACs, and the dependence of the chargestorage capability of ACs on the surface area of ACs has stimulated the interest to fabricate porous ACs to increase specific adsorption sites. 5 However, the topology of ACs is another important factor likely controlling the migration of electrolyte ions during electrochemical cycling.…”

The electrochemical properties of reduced graphene oxide film with capsular pores prepared by using oxalic acid as template

“…upsurge for EDLCs because of its high theoretical specific surface area (SSA), high thermal conductivity, and good electrical conductivity. [16][17][18] Up to date, template method has drawn considerable attention to control the structure of the carbonaceous materials. 6,15 Rationally designing and precisely controlling the structures of carbon-based materials is the effective route to obtain the electrode materials with novel functions and extraordinary properties.…”

“…6,15 Rationally designing and precisely controlling the structures of carbon-based materials is the effective route to obtain the electrode materials with novel functions and extraordinary properties. [16][17][18] Up to date, template method has drawn considerable attention to control the structure of the carbonaceous materials. 7,19 For example, threedimensional networks of carbon nanocage with multiscale pores have been designed by carbonizing and activating the carbon precursor coated on flower-like basic magnesium carbonate microspheres 20 ; by using soft template, the bowl-shaped hollow carbon sphere has also been prepared by combining the hydrothermal and carbonizing method.…”