Escalab 250xi x ray photoelectron spectroscope

The phases of as prepared photocatalysts were characterized by X-ray power diffraction (XRD) on a Rigaku DMAX2500 X-ray diffractometer using a copper target. Particle sizes and morphologies of the samples were determined using transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM) on a JEM-2010 apparatus with an acceleration voltage of 200 kV and field-emission scanning electron microscopy (FE-SEM, HITACHI S-4800). Element distribution was obtained on energy-dispersive X-ray spectroscopy (EDX). UV-vis diffuse reflectance spectra (UV-DRS) of the samples were measured using a Lambda 750 UV/Vis spectrometer with BaSO₄ act as the corrected baseline at room temperature. The photoluminescence (PL) spectra of the samples were recorded on Edinburgh Instruments FLS 920 spectrometer at an excitation wavelength of 320 nm. Surface composition and chemical states were analyzed with a Thermo Scientific Escalab 250Xi X-ray photoelectron spectroscope (XPS) equipped with Al Kα radiation, and the binding energy was calibrated by the C1s peak (284.6 eV) of the contamination carbon.

High-resolution transmission electron microscopy (HRTEM) of the EDA-GO@Fe₃O₄ was collected with a Tecnai G2-F20 (FEI, USA). The EDS spectrum was collected with an energy-dispersive X-ray spectrometer (FEI, USA). The FT-IR spectrum of EDA-GO@Fe₃O₄ was collected using a Magna-IR 170 spectrometer with KBr pellets at room temperature (Nicolet, USA). TG and DSC curves were recorded using a Q600 thermoanalyzer (TA, USA). The surface elemental composition was analyzed using an ESCALAB 250Xi X-ray photoelectron spectroscope with a resolution of 0.5 eV (Thermo, USA).

Morphology of g-C₃N₄ photocatalysts before and after the H₂+CO₂ plasma modification was recorded by a JEM-2200F transmission electron microscope (TEM) at an accelerating voltage of 300 kV. The polymerization structure of the photocatalysts was determined by an X-ray diffractometer (XRD, Smartlab9K Advance). Fourier transform infrared spectra (FTIR) were recorded with a Nicolet IS5 spectrometer. Solid-state 13C nuclear magnetic resonance (NMR) spectra were acquired on a Bruker Avance III 400 NMR spectrometer. A Thermo Scientific Escalab 250Xi X-ray photoelectron spectroscope (XPS) was run under Al Kα monochromatization to perform XPS elemental analysis and valence spectrum analysis. All ultraviolet-visible (UV-vis) absorption spectra were conducted with a UV-vis absorption spectrophotometer (UV-3600 plus). The photo-electron and hole recombination rates of the photocatalysts were determined by a fluorescence spectrometer (PL, Hitachi FLS1000) at room temperature. Electron paramagnetic resonance (EPR) signals were investigated on a Bruker model EPR A300 spectrometer. Electrochemical impedance spectroscopy (EIS) and transient photocurrents were recorded by a Chi660e electrochemical workstation based on a conventional three-electrode system from frequency 0.01 Hz to 100 kHz at the circuit potential.