Preparation and capacitance performance of polyaniline/titanium nitride nanotube hybrid

Enhanced solar-driven photoelectrochemical water splitting using nanoflower Au/CuO/GaN hybrid photoanodes

Harnessing solar energy for large-scale hydrogen fuel (H2) production shows promise in addressing the energy crisis and ecological degradation. This study focuses on the development of GaN-based photoelectrodes for efficient photoelectrochemical (PEC) water splitting, enabling environmentally friendly H2 production. Herein, a novel nanoflower Au/CuO/GaN hybrid structure was successfully synthesized using a combination of methods including successive ionic layer adsorption and reaction (SILAR), RF/DC sputtering, and metal-organic chemical vapour deposition (MOCVD) techniques. Structural, morphological, and optical characteristics and elemental composition of the prepared samples were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), UV-Vis spectroscopy, and energy-dispersive X-ray (EDX) spectroscopy, respectively. PEC and electrochemical impedance measurements were performed for all samples. The nanoflower Au/CuO/GaN hybrid structure exhibited the highest photocurrent density of ∼4 mA cm-2 at 1.5 V vs. RHE in a Na2SO4 electrolyte with recorded moles of H2 of about 3246 μmol h-1 cm-2. By combining these three materials in a unique structure, we achieved improved performance in the conversion of solar energy into chemical energy. The nanoflower structure provides a large surface area and promotes light absorption while the Au, CuO, and GaN components contribute to efficient charge separation and transfer. This study presents a promising strategy for advancing sustainable H2 production via efficient solar-driven water splitting.

Fabrication of composite material of RuCo2O4 and graphene on nickel foam for supercapacitor electrodes

Supercapacitors are energy storage devices with the advantage of rapid charging and discharging, which need a higher specific capacitance and superior cycling stability. Hence, a composite material consisting of RuCo₂O₄ and reduced graphene oxide with a nanowire network structure was synthesized on nickel foam using a one-step hydrothermal method and annealing process. The nanowire network structure consists of nanowires with gaps that provide more active sites for electrochemical reactions and shorten the diffusion path of electrolyte ions. The prepared electrodes exhibit outstanding electrochemical performance with 2283 F g⁻¹ at 1 A g⁻¹. When the current density is 10 A g⁻¹, the specific capacitance of the electrodes is 1850 F g⁻¹, which maintains 81% of the initial specific capacitance. In addition, the prepared electrodes have a long-term cycling life with capacitance retention of 92.60% after 3000 cycles under the current density of 10 A g⁻¹. The composite material is a promising electrode material for high-performance supercapacitors.

The RuCo₂O₄/rGO@NF composite electrode has been prepared by a one-step hydrothermal method and annealing process, with high specific capacitance and excellent cycle stability.

Maize-like ionic liquid@polyaniline nanocomposites for high performance supercapacitor

In this study, ionic liquids (IL) containing carboxyl and different alkyl chains were fabricated and used to dope polyaniline (PANI). The results revealed that IL@PANI composites could be facilely obtained via template-free polymerization of aniline using ammonium persulfate as the oxidant. The as-prepared IL@PANI composites were measured by FT-IR, XPS, and SEM. Electrochemical performances of IL@PANI nanocomposites were investigated by cyclic voltammetry and galvanostatic charge/discharge. The results indicate that the alkyl chains of ILs have an important influence on the morphology and capacitance performance of IL@PANI electrode materials. With the shorter alkyl group in ILs, IL@PANI materials presented higher specific capacitance. Especially, 1-vinyl-3-carboxymethyl-imidazolium chloride ([VCMIm]Cl)@PANI composite presented the highest specific capacitance. Cycling performance measurement demonstrated that 82% capacitance retention could be achieved after 1000 cycles in 0.5 M H2SO4 aqueous solution. Therefore, our strategy provides a new technique for PANI nanocomposites with tunable morphology and high performance.

Flexible all-solid-state supercapacitors based on polyaniline orderly nanotubes array

Flexible all-solid-state supercapacitors are crucial to meet the growing needs for portable electronic devices such as foldable phones and wearable electronics. As promising candidates for pseudocapacitor electrode materials, polyaniline (PANI) orderly nanotube arrays are prepared via a simple template electrodeposition method. The structures of the final product were characterized using various characterization techniques, including scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR), and X-ray photoelectron spectroscopy (XPS). The obtained PANI nanotube film could be directly used as a flexible all-solid-state supercapacitor electrode. Electrochemical results show that the areal capacitance of a PANI nanotube-based supercapacitor with the deposition cycle number of 100 can achieve a maximum areal capacitance of 237.5 mF cm^-2 at a scan rate of 10 mV s^-1 and maximum energy density of 24.31 mW h cm^-2 at a power density of 2.74 mW cm^-2. In addition, the prepared supercapacitor exhibits excellent flexibility under different bending conditions. It retains 95.2% of its initial capacitance value after 2000 cycles at a current density of 1.0 mA cm^-1, which displays its superior cycling stability. Moreover, the prepared flexible all-solid-state supercapacitor can power a light-emitting-diode (LED), which meets the practical applications of micropower supplies.

Fabrication and supercapacitor behavior of phosphomolybdic acid/polyaniline/titanium nitride core–shell nanowire array

PMo₁₂/PANI/TiN was designed by electrostatic adsorption between the heteropolyanion PMo₁₂O₄₀³⁻ and proton-doped PANI.

All Metal Nitrides Solid-State Asymmetric Supercapacitors

Two metal nitrides, TiN porous layers and Fe2 N nanoparticles, are grown uniformly with the assistance of atomic layer deposition on vertically aligned graphene nanosheets and used as the cathode and anode for solid-state supercapacitors, respectively. Full cells are constructed and show good flexibility, high-rate capability, and 98% capacitance retention after 20,000 cycles.

Preparation of carbon-coated lithium iron phosphate/titanium nitride for a lithium-ion supercapacitor

Carbon-coated lithium iron phosphate supported on a titanium nitride nanowire network was designed as the electrode material for a lithium-ion supercapacitor.

Electrochemical capacitance of a carbon quantum dots–polypyrrole/titania nanotube hybrid

Carbon quantum dots modified polypyrrole/titania (CQDs–PPy/TiO₂) nanotube hybrid was designed as supercapacitor electrode material and showed higher capacitive performance than PPy/TiO₂.

Evolution of cellulose into flexible conductive green electronics: a smart strategy to fabricate sustainable electrodes for supercapacitors

The integration of cellulose with electronic elements could form green electronics with the merits of the biopolymer and conductive polymer.

Preparation and electrochemical capacitance of graphene/titanium nitride nanotube array

The graphene composite electrode material was synthesized on the substrate of titanium nitride nanotube array (TiN NTA) through a simple adsorption–reduction process, forming chemical reduction graphene/TiN NTA (G/TiN NTA) and thermal reduction graphene/TiN NTA (TRG/TiN NTA).

SERS performance of graphene oxide decorated silver nanoparticle/titania nanotube array

A schematic illustrates the preparation of recyclable GO/Ag/TiO₂ NTA substrate keeping both active SERS detection and photocatalytic self-cleaning properties.