Uv 2600 spectrophotometer

A UV-2600 spectrophotometer (Unico, Shanghai, China) was used to measure the absorption of EPS-1, EPS-2, and EPS-3 (1 mg/mL) from 190 to 500 nm. EPS-1, EPS-2, and EPS-3 (1 mg) were added with potassium bromide (KBr, 100 mg), then they were pressed into 1 millimeter-thick pellets for measurement. Moreover, an FT-IR spectrometer (Bruker Vetex70, Karlsruhe, Germany) was used to scan in the range of 4000–400 cm⁻¹ [21 (link)].

The morphology of the samples was characterized by a Phenom World Phenom ProX scanning electron microscope (SEM) and a JEOL JEMe1200EX transmission electron microscopy (TEM). Both the SEM and TEM were used with an accelerating voltage of 200 kV. The X-ray diffraction (XRD) patterns of the samples were recorded by a X-ray powder diffractometer using a Cu Kα source (λ = 0.15418 nm) at a scanning rate of 2°/min between 5° and 80°. A Thermo Fisher VG Scientific VG ESCALAB250Xi electron spectrometer was used to observe X-ray photoelectron spectroscopy (XPS) results. A monochromatic Al Kα source (1486.7 eV) and a 300 × 500 μm spot size was used to collect the spectra. In 77 K nitrogen atmosphere, the specific surface area and pore size distribution of the sample were determined by a Micromeritics ASAP 2020 surface area and porosity measurement system. A Unico UV-2600 spectrophotometer was used to analyze the concentration of RhB in the photocatalytic process. The photoelectrochemical properties were analyzed using electrochemical workstations (Gamry interface 1010 and Chenhua CHI700E) with blue light (400–450 nm) irradiation. The steady-state photoluminescence (PL) spectra of the samples were detected by using a Hitachi F-7000 fluorescence spectrophotometer with excitation at 280 nm.