CoFeS2@CoS2 Nanocubes Entangled with CNT for Efficient Bifunctional Performance for Oxygen Evolution and Oxygen Reduction Reactions

Abstract

Exploring bifunctional electrocatalysts to lower the activation energy barriers for sluggish electrochemical reactions for both the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) are of great importance in achieving lower energy consumption and higher conversion efficiency for future energy conversion and storage system. Despite the excellent performance of precious metal-based electrocatalysts for OER and ORR, their high cost and scarcity hamper their large-scale industrial application. As alternatives to precious metal-based electrocatalysts, the development of earth-abundant and efficient catalysts with excellent electrocatalytic performance in both the OER and the ORR is urgently required. Herein, we report a core–shell CoFeS2@CoS2 heterostructure entangled with carbon nanotubes as an efficient bifunctional electrocatalyst for both the OER and the ORR. The CoFeS2@CoS2 nanocubes entangled with carbon nanotubes show superior electrochemical performance for both the OER and the ORR: a potential of 1.5 V (vs. RHE) at a current density of 10 mA cm−2 for the OER in alkaline medium and an onset potential of 0.976 V for the ORR. This work suggests a processing methodology for the development of the core–shell heterostructures with enhanced bifunctional performance for both the OER and the ORR.

Construction of Core–Shell CoMoO4@γ-FeOOH Nanosheets for Efficient Oxygen Evolution Reaction

“…Wang's group has recently reported that the core-shell structure of Au@NiCo 2 S 4 core-shell NPs could result in a higher proportion of high-valance Ni/Co cations and improve its electronic conductivity, which collectively enhances its OER catalytic performance [20]. In addition, a great number of the heterostructures have also been fabricated for an improved electronical performance, such as CoP/FeP 4 [21], Co 9 S 8 /CoO/NC [22], CoFeS 2 @CoS 2 [23], Ni-P-S@FeOOH/CC [24], Ni 5 P 4 /Ni 2 P-FeNi [25], and MnO-OVs/NCNTs [26].…”

Research Progress of Bifunctional Oxygen Reactive Electrocatalysts for Zinc–Air Batteries

“…Changing the specific surface area and the surface interface properties of catalysts can affect their catalytic properties; hence, the structure of the materials can be reasonably designed and regulated to obtain the desired catalytic properties. The synthesis methods of the catalysts are mainly divided into thermal decomposition, electrodeposition, and electrospinning [ 85 , 86 ]. During OER/ORR, the adsorption energy of the oxygen intermediates depends on the surface geometry.…”

In situ decorated Cu2FeSnS4 nanosheet arrays for low voltage hydrogen production through the ammonia oxidation reaction

“…Whereas the peak corresponding to sulfur-oxygen bonding at the binding energy of 169.5 eV has become significant, inferring the oxidation of sulfur during the water oxidation process, which is quite sensible to observe in catalysts like CFTS and has been reported similarly in related reports. 70,71 Moreover, the oxidation of transition metal sulfides upon the long-term OER reaction under strong alkaline conditions is investigated in detail and has been reported to be thermodynamically unavoidable by Han et al 71 Furthermore, a partial oxidation process occurs during the long-term OER, resulting in the formation of an amorphous oxide layer on the electrocatalyst, which is beneficial for the adsorption and desorption of OH and H atoms, ensuring undeteriorated performance even after the long-term OER reaction. 71 However, the XRD pattern of EG-CFTS after the AOR test for 20 h revealed that there was no significant change in the crystal phase (Fig.…”