NiCo2O4/MWCNT/PANI coral-like nanostructured composite for electrochemical energy-storage applications

Recent Research of NiCo2O4/Carbon Composites for Supercapacitors

Supercapacitors have played an important role in electrochemical energy storage. Recently, researchers have found many effective methods to improve electrode materials with more robust performances through the increasing volume of scientific publications in this field. Though nickel cobaltite (NiCo2O4), as a promising electrode material, has substantially demonstrated potential properties for supercapacitors, its composites usually show much better performances than the pristine NiCo2O4. The combination of carbon-based materials and NiCo2O4 has been implemented recently due to the dual mechanisms for energy storage and the unique advantages of carbon materials. In this paper, we review the recent research on the hybrids of NiCo2O4 and carbon nanomaterials for supercapacitors. Typically, we focused on the reports related to the composites containing graphene (or reduced graphene oxide), carbon nanotubes, and amorphous carbon, as well as the major synthesis routes and electrochemical performances. Finally, the prospect for the future work is also discussed.

Controlled Growth of 3D Interpenetrated Networks by NiCo2O4 and Graphdiyne for High-Performance Supercapacitor

In this paper, the 2D all-carbon graphdiyne, which possesses superior 2D strength and high mixed conductivities for both electrons and ions, is used to protect nickel cobalt oxide nanostructures with multidimensions. The in situ grown graphdiyne seamlessly wraps on nanostructures to form 3D interpenetrating networks, leading to significant improvement in the conductivity and avoidance of the structural degradation. The assembled hybrid asymmetric supercapacitor showed a high specific capacitance of 200.9 F g^-1 at 1 A g^-1 with an energy density of 62.8 Wh kg^-1 and a power density of 747.9 W kg^-1. The device also showed a preeminent rate capability (86.4% capacitance retention, while the current density was increased from 1 to 20 A g^-1) and an ultrastable long-term cycling performance (the capacitance retention is about 97.7% after 10 000 cycles at a high current density of 20 A g^-1).

Understanding the Z-scheme heterojunction of BiVO4/PANI for photoelectrochemical nitrogen reduction

Based on the idea that a heterojunction can significantly promote photoelectrochemical (PEC) efficiency, BiVO₄/PANI (polyaniline), as a Z-scheme heterojunction, was designed in this work. BiVO₄/PANI achieved a desirable NH₃ yield rate (r_NH3 = 0.93 μg h^-1 cm^-2) and faradaic efficiency (FE = 26.43%). This study presents novel insight into PEC NRR research, and it could be extended to the modification of other catalysts for boosting PEC N₂ reduction reaction performance.