Developing cost-effective, efficient, and durable bifunctional non-noble metal electrocatalysts is crucial for addressing the energy crisis. Electronic modulation of intrinsic materials by vanadium doping enhances catalytic activity; thus, unique nanodendrites over 2D nanosheets of vanadium-doped CoTe₂/MoTe₂ on carbon cloth (V-CoTe₂/MoTe₂@CC) are engineered by hydrothermal treatment and subsequent tellurization. V dopants modulate the electronic environment of CoTe₂/MoTe₂, increasing binding energies, decreasing the energy barrier, and creating multiple active sites at elevated lattices to accelerate the reaction kinetics for water splitting. As a result, V-CoTe₂/MoTe₂@CC shows outstanding catalytic performance for the HER (η₁₀ = 79 mV), OER (η₁₀ = 249 mV), and overall water splitting requiring 1.51 V to deliver 10 mA cm⁻². V-CoTe₂/MoTe₂@CC demonstrates impressive durability for up to 100 h of continuous operation, signifying its potential practical application. This work establishes V-CoTe₂/MoTe₂@CC as an effective bifunctional electrocatalyst and also introduces a salient approach to tuning electronic structures for high-performance electrocatalysts.

In this work, we report the carbon fiber-based wire-type asymmetric supercapacitors (ASCs). The highly conductive carbon fibers were prepared by the carbonized and graphitized process using the polyimide (PI) as a carbon fiber precursor. To assemble the ASC device, the CoMnO₂-coated and Fe₂O₃-coated carbon fibers were used as the cathode and the anode materials, respectively. Herein, the nanostructured CoMnO₂ were directly deposited onto carbon fibers by a chemical oxidation route without high temperature treatment in presence of ammonium persulfate (APS) as an oxidizing agent. FE-SEM analysis confirmed that the CoMnO₂-coated carbon fiber electrode exhibited the porous hierarchical interconnected nanosheet structures, depending on the added amount of APS, and Fe₂O₃-coated carbon fiber electrode showed a uniform distribution of porous Fe₂O₃ nanorods over the surface of carbon fibers. The electrochemical properties of the CoMnO₂-coated carbon fiber with the concentration of 6 mmol APS presented the enhanced electrochemical activity, probably due to its porous morphologies and good conductivity. Further, to reduce the interfacial contact resistance as well as improve the adhesion between transition metal nanostructures and carbon fibers, the carbon fibers were pre-coated with the Ni layer as a seed layer using an electrochemical deposition method. The fabricated ASC device delivered a specific capacitance of 221 F g⁻¹ at 0.7 A g⁻¹ and good rate capability of 34.8% at 4.9 A g⁻¹. Moreover, the wire-type device displayed the superior energy density of 60.2 Wh kg⁻¹ at a power density of 490 W kg⁻¹ and excellent capacitance retention of 95% up to 3000 charge/discharge cycles.

In this work, we prepared network-structured carbon nanofibers using polyacrylonitrile blends (PAN150 and PAN85) with different molecular weights (150,000 and 85,000 g mol⁻¹) as precursors through electrospinning/hot-pressing methods and stabilization/carbonization processes. The obtained PAN150/PAN85 polymer nanofibers (PNFs; PNF-73, PNF-64 and PNF-55) with different weight ratios of 70/30, 60/40 and 50/50 (w/w) provided good mechanical and electrochemical properties due to the formation of physically bonded network structures between the blended PAN nanofibers during the hot-processing/stabilization processes. The resulting carbonized PNFs (cPNFs; cPNF-73, cPNF-64, and cPNF-55) were utilized as anode materials for supercapacitor applications. cPNF-73 exhibited a good specific capacitance of 689 F g⁻¹ at 1 A g⁻¹ in a three-electrode set-up compared to cPNF-64 (588 F g⁻¹ at 1 A g⁻¹) and cPNF-55 (343 F g⁻¹ at 1 A g⁻¹). In addition, an asymmetric hybrid cPNF-73//NiCo₂O₄ supercapacitor device also showed a good specific capacitance of 428 F g⁻¹ at 1 A g⁻¹ compared to cPNF-64 (400 F g⁻¹ at 1 A g⁻¹) and cPNF-55 (315 F g⁻¹ at 1 A g⁻¹). The cPNF-73-based device showed a good energy density of 1.74 W h kg⁻¹ (0.38 W kg⁻¹) as well as an excellent cyclic stability (83%) even after 2000 continuous charge–discharge cycles at a current density of 2 A g⁻¹.

P-doped NiTe ₂ /CoTe ₂ mesoporous nanosheets on carbon cloth show enhanced HER/OER activity and stability for overall water splitting, driven by P-induced electronic modulation, Ni–Co synergy, and mesoporous architecture.

Ordered and disordered mesoporous structures were synthesized by a self-assembly method using a mixture of phenolic resin and petroleum-based mesophase pitch as the starting materials, amphiphilic triblock copolymer F127 as a soft template, hydrochloric acid as a catalyst, and distilled water as a solvent. Then, mesoporous carbons were obtained via autoclave method at low temperature (60 °C) and then carbonization at a relatively low temperature (600 °C), respectively. X-ray diffraction (XRD), small-angle X-ray scattering (SAXS), and transmission electron microscopy (TEM) analyses revealed that the porous carbons with a mesophase pitch content of approximately 10 wt% showed a highly ordered hexagonal mesostructure with a highly uniform pore size of ca. 5.0 nm. In addition, the mesoporous carbons prepared by self-assembly and low-temperature autoclave methods exhibited the amorphous or crystalline carbon structures with higher specific surface area (SSA) of 756 m²/s and pore volume of 0.63 cm³/g, depending on the synthesis method. As a result, mesoporous carbons having a high SSA were successfully prepared by changing the mixing ratio of mesophase pitch and phenolic resin. The electrochemical properties of as-obtained mesoporous carbon materials were investigated. Further, the OMC-meso-10 electrode delivered the maximum SC of about 241 F/g at an applied current density of 1 A/g, which was higher than those of the MC-10 (~104 F/g) and OMC-20 (~115 F/g).