FIGURE 5 Cross-sectional and Top-view (inset) SEM images of the tubular MXene/SS membranes grown with different electrophoresis time.
XRD characterization of the tubular MXene/SS membranes with different electrophoresis time was performed, as shown in Figure 6. The corresponding d -spacing could be calculated using the Bragg equation \(2d\sin\theta=n\lambda\) and finally the empty interlayer spacing \(l=d-l_{0}\) was calculated, where \(l_{0}\) was the thickness of the theoretical monolayer MXene nanosheet. Since it was inconvenient for sample preparation due to the hard tubular stainless steel substrate, an electric conductive adhesive (ECA) was used to stick the membrane on the holder to perform XRD characterization. Because the ECA contained metal aluminum flakes, there were diffraction peaks of metal aluminum at 44.59, 64.97, and 78.12° in the XRD patterns, respectively. The angle of (002) diffraction peak of a series of tubular MXene/SS membranes prepared by electrophoretic deposition was around 6.42° withd -spacing of 1.375 nm, where the empty interlayer spacing was 0.375 nm. To verify whether the electrophoretic deposition process had an effect on the interlayer spacing of the tubular MXene/SS membrane, another MXene membrane prepared by vacuum filtration (labeled as MXene/ECAVF) was also performed. It could be obtained from the XRD patterns that the MXene/ECAVF membrane exhibited a diffraction peak of 002 crystal plane at an angle of 6.50° with the d -spacing of 1.358 nm (empty interlayer spacing of 0.358 nm), which was consistent with our previous work and other literature.59,60