Escalab 250xi photoelectron spectrometer

The porous structure and surface topography of melamine before and after PN growth was observed by using a Sirion-200 scanning electron microscope (FEI, USA). The absorbance spectra of the purifier were measured using a Varian UV–vis spectrophotometer (Cary 5000, USA), coupled with an Agilent integrating sphere. An IR camera (Fluke) was used to measure the temperature increase under solar irradiation. The wettability change of the purifier after solar irradiation was measured by the contact angle analysis system with a 3.0-μL water droplet. Raman spectra were obtained by using LabRAM HR Evolution (HORIBA Jobin Yvon, France) Raman microscope with a 514-nm laser. Elemental analysis was finished using XPS spectra taken out by an ESCALAB 250XI photoelectron spectrometer (ThermoFisher Scientific, USA). X-ray diffractions (XRD) were carried out using a D8 Advance X-ray diffractometer with Cu Kα radiation (λ = 0.15418 nm, Bruker, Germany). The transpiration and guttation experiments were conducted in the lab using a solar simulator with an optical filter for the standard AM 1.5G spectrum. The optical concentrations of 1 sun and 2 sun are 100 and 200 mW cm⁻², respectively. The contact angle was measured using a Dataphysics OCA 15pro CA measuring instrument (DataPhysics Instruments GHPH, Filderstadt).

The crystal structure of the FeF₃@C was characterized using X-ray diffraction (XRD) (Bruker, Billerica, MA, USA) with high-intensity Cu Kα radiation. The chemical bonding state was analyzed by X-ray photoelectron spectroscopy (XPS) using a Thermo Scientific ESCALAB 250XI photoelectron spectrometer (Thermo Fisher Scientific, Wuhan, China). The surface morphology was investigated by scanning electron microscope (SEM; JSM-6700F) (JEOL, Beijing, China). Transmission electron microscopy (TEM) and high-resolution transmission electron microscopy (HR-TEM) were carried out by a JEOL 100CX instrument (JEOL, Beijing, China). The porosity of the materials was characterized by using ASAP-2010 (Micromeritics, Shanghai, China).

Catalyst morphology was observed using scanning electron microscopy (SEM), which was performed on an analytical SEM SU-70 (Hitachi, Japan) microscope operating at a voltage of 10 kV. Catalyst surface loading was analyzed using transmission electron microscopy (TEM), which was performed on a JEM-2100F microscope (JEOL, Japan) operating at a voltage of 200 kV. Use X-ray diffraction (XRD) to scan and analyze the prepared catalyst powder to obtain the diffraction pattern, using Cu Kα radiation, a voltage of 40 kV, a current of 20 mA (λ = 1.5406 Å), and a conventional angle of 5–80°, and compared to the International Center for Diffraction Data (ICDD) powder diffraction file (PDF) database for data processing. An IRTracer 100 (Shimadzu, Japan) Fourier Infrared Spectrometer (FT-IR) was used to evaluate the possible presence of functional groups in the samples. Metal valence states were analyzed using X-ray photoelectron spectroscopy (XPS) with Al Kα X-ray radiation on an Escalab 250 Xi photoelectron spectrometer (Thermo Fisher Scientific, USA) with a scan number of 5. The Brunauer–Emmett–Teller (BET) surface area and pore volume of the nanocomposites were measured by nitrogen physical adsorption at liquid nitrogen temperature on a Mac-ASAP-2460 (Quantachrome, U.S.A.). Pore size distributions were obtained using the Barrett–Joyner–Halenda (BJH) method.