Su8220 device

XRD was performed on a TD‐3500 (Tongda, China) diffractometer, and SEM observations were made on a Hitachi SU‐8220 device. TEM images were captured with a JEM‐2100HR microscope (JEOL, Japan). XPS data were measured using a K‐Alpha+ photoelectron spectrometer (Thermo Fisher Scientific).

The atomic force microscopy (AFM) images were obtained using a Bruker Dimension Icon scanning probe microscope (SPM) in PeakForce tapping mode. The scanning electron microscopy (SEM) images were obtained from the Hitachi SU8220 device (Ibaraki, Japan). The water contact angle was measured using an automatic contact angle measuring instrument (Biolin, Attension Theta, Gothenburg, Sweden). The X-ray photoelectron spectroscopy (XPS) analysis was carried out using a theta probe spectrometer (Thermo Fisher, Brno, Czech Republic) with monochromatic Al-Kα radiation (1486.6 eV). Raman spectroscopy was performed on a Renishaw inVia Reflex Raman microscope (London, England) with 633 nm laser excitation. The FTIR characterization was carried out using a Thermofisher IS50 spectrometer (Brno, Czech Republic) in attenuated total reflection (ATR) mode in the wavenumber range of 400–4000 cm⁻¹. The X-ray diffraction (XRD) analysis was performed using Rigaku Smart Lab X-Ray Diffractometer (Japan) with filtered Cu-Kα radiation (40 kV and 40 mA, λ = 0.154 nm).

SEM images were obtained using a Hitachi SU8220 device. The SEM elemental mapping analysis was conducted using an EDX (Oxford EDS, with INCA software). TEM images were obtained using a JEOL JEM-2100F microscope with an acceleration voltage of 200 kV. Elemental mapping in TEM was conducted using the Bruker EDS System. The XRD analysis was carried out using a Bruker D8 Advance with filtered Cu-Kα radiation (40 kV and 40 mA, λ = 0.154 nm); the step scan was 0.02°, the 2θ range was 2–10° or 2–70°, and the step time was 2 s. FTIR was conducted by Bruker VERTEX 33 units in the wavenumber range of 400–4000 cm⁻¹. The XPS analysis was performed using an ESCALAB 250 spectrometer (Thermo Fisher Scientific) with monochromated Al-Kα radiation (1486.6 eV) under a pressure of 2 × 10⁻⁹ Torr. The AFM images were obtained using a Bruker Multi Mode 8 scanning probe microscope (SPM, VEECO) in tapping mode. The TG measurement was analyzed on a Netzsch STA 449F3 instrument under the flow of N₂. The adsorption isotherms of H₂, CO₂, N₂, and CH₄ on the MXene membranes were measured using a Micromeritics (ASAP 2460) instrument. The mechanical tests were performed using an Instron-5565 universal testing machine (USA).