4100 spectrophotometer

X-ray diffraction (XRD) analyses were conducted using a Bruker D8-Focus diffractometer equipped with Cu Kα radiation. The morphology of the synthesized sample was examined via a scanning electron microscope (SEM, SU8010, Hitachi Ltd., Chiyoda, Japan) across an acceleration voltage range of 200 V to 30 kV, supplemented by energy dispersive X-ray (EDX) spectroscopy for elemental analysis. The interplanar spacing of the lattice fringes was determined using a high-resolution transmission electron microscope (HRTEM, Tecnai F20, FEI Company, Hillsboro, OR, USA). Ultraviolet-visible diffuse reflectance spectra (DRS) were acquired on a Hitachi 4100 spectrophotometer, employing BaSO₄ as the reference standard. X-ray photoelectron spectroscopy (XPS) measurements were performed on a PHI Quantera ULVAC XPS system (ULVAC, Inc., Chigasaki, Japan). Photoelectrocatalytic (PEC) characterizations were conducted in a quartz electrochemical cell, incorporating a three-electrode setup, with an electrochemical workstation (CHI 660D, CH Instruments, Inc., Shanghai, China). A 0.1 M solution of Na₂SO₄ served as the electrolyte. Electrochemical impedance spectroscopy (EIS) was executed over a frequency range from 0.005 Hz to 105 Hz, applying a sinusoidal AC disturbance signal of 5 mV to probe the electrochemical properties of the materials.

The reflectance and transmittance of the Al-Ag nanohelix array were measured using Hitachi 4100 spectrophotometer. The spectra were measured at wavelengths from 400 nm to 850 nm with photomultiplier and wavelengths from 850 nm to 2000 nm with cooled type Pbs(Polycrystalline lead sulfide detectors). At oblique incidence, p-polarized and s-polarized spectra were measured separately at angles of incidence from 20° to 70° in steps of 5 degrees.