Chi 660e electrochemical workstation

A Japan SHIMADZU SSX-550 scanning electron microscope (SEM) equipped with an energy-dispersive X-ray spectrometer (EDX) was used to examine the morphology and composition of the as prepared samples. The image visualization software ImageJ was used to analyze the mean diameters of the composite micro-nanofibers. 100 measurements per field were chosen based on the SEM images.^{29 (link)} Thermal gravimetric analysis (TGA) was performed on a PerkinElmer Pyris 1 TGA (United States) from room temperature to 800 °C under a flowing air atmosphere. The vibration in the functional groups of the micro-nanofibers was analyzed using a Japan SHIMADZU 1.50SU1 Fourier transform-infrared radiation (FT-IR) spectrometer. X-ray powder diffractometry (XRD) was conducted on a Siemens X-ray diffractometer (D5005XRD) to study the crystal structure of the calcined micro-nanofibers. Scans were set from 30 to 70° (2θ). All electrochemical experiments were performed on a CHI 660E Electrochemical Workstation (CH Instruments, USA), using a traditional three-electrode electrochemical cell (a working volume of 5 mL) with a working electrode, a saturated calomel electrode, and a platinum wire counter electrode.

Scanning electron microscopy (SEM, Hitachi S-4800) was used to measure the surface morphology of the sample at an accelerating voltage of 15 kV. The thickness of samples was tested via atomic force microscopy (AFM, Veeco-Multimode-V, Plainview, NY, USA). X-ray diffraction (XRD) patterns were reported on a powder X-Ray diffractometer (D8 ADVANCE, Bruker, Germany) with Cu Kα (λ = 0.154 nm) radiation. Transmission electron microscopy (TEM) and high-resolution TEM were measured on an FEI Tecnai G20 at 120 and 200 kV acceleration voltage, respectively.
All electrochemical tests were operated at a CHI 660E electrochemical workstation (CH Instruments, Austin, TX, USA) with a classical three-electrode electrochemical cell. Among them, the working electrode was modified electrode or glassy carbon electrode (GCE), the counter electrode was platinum disk electrode, and the reference electrode was saturated calomel electrode (SCE).

Electrochemical measurements were carried out on a CHI660e electrochemical workstation (Shanghai CH Instruments Ins., Shanghai, China) in a classical three-electrode, along with as-prepared Co-MOF on Ni foam as the work electrode, a Pt plate as the counter electrode, and an Hg/HgO as the reference electrode. Next, 2 M KOH was chosen to be the electrolyte. Cyclic voltammetry (CV) measurements were displayed at different scan rate (2–50 mV s⁻¹) with a potential range from 0 to 0.6 V. Galvanostatic charge discharge (GCD) curves were performed at different current densities (2–50 mA cm⁻²) with a potential range from 0 to 0.5 V.
The area specific capacitance (Cs) of as-prepared active Co-MOF on a Ni foam electrode was calculated by the following equation: $C_s=\frac{I\times \mathsf{\Delta }t}{s}$ where I, Δt, and s represent the discharge current (A), discharge time (s), and the area (cm²) of the electrode, respectively.
The home-made ACS device was assembled by using as-prepared Co-MOF on Ni foam as the cathode and active carbon-coated Ni foam as the anode, with a cellulosic separator in between. The mass ratio of cathode to anode was determined according to the charge balance equation. The area energy density E (Wh cm⁻²) and power density P (W cm⁻²) were calculated by the following equations: $E=\frac{C\mathsf{\Delta }{V}^2}{2}\times \frac{1000}{3600}$
$P=\frac{E}{\mathsf{\Delta }t}\times 3600$

The photoelectrochemical measurements were performed on CHI 660E electrochemical workstation (CH Instruments) in three-electrode system under light irradiation. In all, 3.0 mg of catalyst was dispersed in 800 μL of DI water and then dropped onto a 1 × 3 cm fluorine-doped tin oxide (FTO)-coated glass for employed as work electrode. The Pt foil and saturated Ag/AgCl electrode were used as counter electrode and reference electrode, respectively. 0.5 M Na₂SO₄ aqueous solution was chosen as the electrolyte. The electrolyte was saturated with pure Ar or CH₄ prior before the tests. The photocurrent responses of the prepared photoelectrodes (i.e., I–t) were operated by measuring the photocurrent densities under chopped light irradiation (light on/off cycles: 50 s) at a bias potential of 0.8 V vs. Ag/AgCl for 800 s.

The reflectance spectra of the films were measured using a UV–vis spectrophotometer (V660, JASCO) equipped with an integrating sphere measurement system. A spectroscopic ellipsometer (RC2 XI, J. A. Woollam Co., Inc.) was used to measure the optical constants of all materials. The tensile stress–strain curves of the CNT films were obtained using a tensile testing machine Instron 3365 with a gauge length of 10 mm at a loading rate of 1 mm min⁻¹. The current–voltage curves of the CNT films were obtained using a CHI660E electrochemical workstation (CH Instruments, Inc.). To assess the conductivity stability of the colored films at high temperatures, the colored carbon film and LED were connected in series with a power supply, and the brightness of the LED was observed over time while the alcohol lamp was lit, and a voltage of 2.5 V was applied. The UV radiation resistance test was conducted by irradiating the films with a 325‐nm UV laser for 4 months at a power of 625 W m⁻². The color difference was computed using a Python‐based color space conversion library to transform the reflectance spectra of the colors into their corresponding chroma coordinates in the XYZ color space. Subsequently, the L*a*b* value of the sample under the D65 illuminant was determined, and the appropriate formula was applied to evaluate the color difference between the two samples.