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