Search

Metal–organic framework (MOF)-derived electroactive materials have drawn great attention due to their diverse design and high electrochemical activity. Herein, a unique hybrid structure consisting of Ni–Co layered double hydroxides (LDHs) and hollow carbon spheres (HCSs) is first synthesized using HCS@ZIF-67 as a precursor. Particularly, when the ZIF-67 content in the precursor is optimized, a novel hybrid with a hollow-in-hollow structure can be obtained by distributing ZIF-67-derived hollow Ni–Co LDHs on a HCS shell. Owing to their distinctive structural characteristics, the as-prepared architectures deliver a high specific capacity (156.4 mA h g−1 at 5 A g−1) and excellent cycle stability (73.4% capacity retention after 10 000 cycles). Notably, during the charge storage process, the dual hollow system of the composite effectively decreases the ion diffusion path, resulting in drastically improved rate performance (70% retention of its highest capacity at 80 A g−1). Furthermore, an all-solid-state hybrid supercapacitor is assembled using the as-fabricated hybrid as the positive material and mesoporous plasma-reduced graphene oxide as the negative material, and exhibits a maximum energy density of 34.5 W h kg−1 and a peak power density of 55 kW kg−1.

Hierarchical fibrous structures composed of ZnO quantum dots, amorphous carbons, and carbon nanofibers are synthesized via a single carbonization process of electrospun ZIF-8/PVA nanofibers. This newly designed electrode material for supercapacitors exhibits outstanding electrochemical performances with high capacitance, reliable rate capability, and long cycle life.

One-dimensional (1D) carbon materials are typically used for electric double layer capacitor (EDLC) electrodes due to their excellent charge carrier mobility. However, improvement of the low capacitance and energy density of these carbon-based EDLCs has been required although they have a fast charge/discharge rate and long cycle life. In this work, nitrogen and fluorine doped mesoporous carbon nanofibers (NFMCNFs) were fabricated using a hydrothermal treatment for structural modification to create porosity and a vacuum plasma process for introducing heteroatoms into the carbon lattice. Applied to supercapacitor devices, the NFMCNFs exhibited a remarkable EDLC performance of 252.6 F g−1 at 0.5 A g−1 in a 1 M H2SO4 electrolyte. Additionally, all-solid-state flexible symmetric supercapacitors (SSCs) were assembled with a high specific capacitance of 58.1 F g−1 at 0.5 A g−1 and outstanding long-term cycle stability over 20 000 cycles. Remarkably, the SSCs also exhibited high energy and power densities of 8.07 W h kg−1 and 248 W kg−1, respectively. This dynamic porous structure and heteroatom co-doping based carbon material provides a sensational approach for designing energy storage systems.

A fluorine plasma-treated carbon electrode is used in HTM-free perovskite solar cells for high efficiency and moisture resistance. The fluorine-treated device with a champion power conversion efficiency (PCE) of 14.86% is achieved with a highly enhanced FF (FF = 0.69), showing superior long-term stability and excellent moisture penetration suppression.

A new, simple method is reported to enhance the electrorheological (ER) activity of nanomaterials. Plasma treatment was the ideal technique owing to its ease of use, versatility, and common usage in mass production. Multi-gram quantities of ER nanomaterials with different morphologies, sizes, and compositions were successfully treated by ammonia plasma.

In this report, a polyaniline/MoS2 nanocomposite has been firstly produced using a self-stabilized dispersion polymerization method. The synthesized polyaniline/MoS2 nanocomposite exhibited a remarkably high electrical conductivity of ca. 28.6 S cm−1, which is higher than other previously reported MoS2-based composites. Additionally, the PANI/MoS2 nanocomposite exhibited substantially improved capacitance (ca. 400 F g−1) compared to pristine MoS2 nanosheets (ca. 3 F g−1) and PANI (ca. 232 F g−1) and enhanced cycling stability (retention rate of 84%) in comparison with pure PANI (retention rate of 62%). Furthermore, the PANI/MoS2 nanocomposite demonstrated a higher energy density (4.7 W h kg−1 at 1000 W kg−1) than conventional electrochemical capacitors and other previously reported carbon and carbon/conducting polymer based electrochemical capacitors owing to its high utilizing of pseudocapacitance attributed to high electrical conductivity. What is more, the synthesized PANI/MoS2 nanocomposite demonstrated good rate capability and a good power characteristic as the supercapacitor electrode by keeping its high energy density (3.8 W h kg−1) at a high power density (2000 W kg−1) due to the existence of sufficient empty space between interconnected PANI nanofibers and high electrical conductivity of the PANI/MoS2 nanocomposite.

Recently, using graphene oxide (GO) for “carbocatalysis” has been very attractive as a novel application of graphene-based nanomaterials and is expected to open a host of possibilities for chemical synthesis because of the abundance of natural carbon sources, as well as the low density, extensive chemical functionalization, hydrophilicity, low cost, and ease of preparation. Here, we demonstrate that the GO can play a role as a chemical oxidant for various CPs (polythiophene, polyaniline, and polypyrrole), and diverse graphene–CP composites (graphene–polythiophene, graphene–polyaniline, and graphene–polypyrrole) can simply and rapidly be synthesized by using the GO as both graphene precursor and chemical oxidant. The UV–vis analysis confirms that the GO has successfully polymerized the CPs and been transformed to reduced graphene oxide (RGO). The SEM and TEM analyses show that the CPs have successfully been coated on the few-layered graphene sheets. Raman analysis and series of FT-IR analyses have been con...