Cobalt oxide nanosheets anchored onto nitrogen-doped carbon nanotubes as dual purpose electrodes for lithium-ion batteries and oxygen evolution reaction

Abstract

Summary Transition metal oxides (TMOs) have been extensively explored as promising electrode materials for electrochemical energy storage and catalysis. However, TMOs intrinsically have low electronic conductivity and suffer severe volume change during electrochemical cycling. In this study, we develop an effective strategy to enhance conductivity and buffer volume changes of TMOs, in which networked nitrogen‐doped carbon nanotubes (N‐CNTs) are incorporated into Co3O4 nanosheets system. Based on the whole mass of Co3O4 and N‐CNT, the composites can maintain a stable discharge capacity of ~590 mAh g−1 after 80 cycles at a current density of 0.5 A g−1. Moreover, the composites also exhibit greatly enhanced catalysis ability towards oxygen evolution reaction (OER), ie, small Tafel slope of 84 mV dec−1, low overpotential of 310 mV at a current density of 10 mA cm−2, and almost no activity decay throughout 30‐hour continuous operation. This study lays a new route for smartly designing advanced electrode materials for energy storage and electrochemical catalysis.

Fabrication of FeO@CuCo 2 S 4 multifunctional electrode for ultrahigh‐capacity supercapacitors and efficient oxygen evolution reaction

“…The obtained results are compared with some state-of-art materials reported previously in the literature as shown in Figure 1. [5][6][7][8][9][10]27,37,[40][41][42][43][44][45][46][47][48][49][50][51][52] Herein, we design and fabricate binder-free FeO@CuCo 2 S 4 on the three-dimensional (3D) architecture of porous Ni foam, together with its impressive EES and electrocatalytic OER properties in aqueous alkaline media of KOH. The optimized FeO@CuCo 2 S 4 electrodes show a cordillera-like morphology along with a nanospheres-like island on its surface.…”

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

“…For instance, Wu et al reported the production of Co/N‐doped multifunctional electrode materials by combining cobalt oxide and N‐doped carbon nanotubes (N‐CNT@Co 3 O 4 ). The composite material was prepared by anchoring Co(OH) 2 onto the prepared N‐doped carbon nanotubes via a multistep compound method, followed by pyrolysis . Some researchers have demonstrated that the encapsulation of metal nanoparticles by graphitic carbon layers is a feasible method for enhancing the stability of the metal nanoparticles against electrolytes that induce oxidation and nanoparticle aggregation .…”

“…The composite material was prepared by anchoring Co(OH) 2 onto the prepared Ndoped carbon nanotubes via a multistep compound method, followed by pyrolysis. 24 Some researchers have demonstrated that the encapsulation of metal nanoparticles by graphitic carbon layers is a feasible method for enhancing the stability of the metal nanoparticles against electrolytes that induce oxidation and nanoparticle aggregation. 25 It has been shown that carbon materials obtained by this method contain an abundance of exposed metal active sites and thus possess desirable electrochemical properties.…”

Iron and nitrogen codoped carbon catalyst with excellent stability and methanol tolerance for oxygen reduction reaction

“…The band at 286.3 eV may be assigned to C═N/C─O structure of carbon black, which is associated with the process of pyrolysis. The broader peak at 289.2 eV corresponds to the C═O bonds of different carbon functional groups such as carbonyl or carboxyl, which are usually produced from the carbon sources . From the XPS spectra of Fe 2p (Figure S2B), it can be seen there are two pairs of distinct peaks.…”