XRD analysis shows the formation of MoS2 with a shift of the (002) signal from 13.9° 2θ in nano-MoS2 to 9.0° 2θ for both MoS2-HDA-1 and MoS2-HDA-0.5 samples (Fig. ). This confirms that the addition of HDA pillars to the precursor solution leads to the formation of interlayer-expanded MoS2, with the (002) spacing expanding from 0.64 to 0.98 nm. While the Raman spectrum of nano-MoS2 revealed the formation of the semiconducting 2H phase, the spectra recorded for MoS2-HDA-1 and MoS2-HDA-0.5 samples show a distinctly different signature (Fig. ). The spectra show the characteristic vibrational Raman modes J1 at 153 cm -1 , J2 at 213 cm -1 , J3 at 329 cm -1 and A1g at 412 cm -1 . The spectra indicate the formation of a distorted 1T phase of MoS2 (1T' phase) upon the confinement of HDA pillars as guest species in the MoS2 interlayer space. The distorted 1T phase (1T') can be distinguished from the ideal 1T phase via the presence of the A1g mode at 412 cm -1 and the absence of the E2g mode at 258 cm -1 . We hypothesize that the 1T' phase forms as a consequence of the confined interlayer guest species (i.e., HDA pillars), which has been described for hydrothermally synthesized MoS2 materials with various organic guest species before. The HDA content of the samples was calculated from thermogravimetric analysis (TGA) under O2-containing atmosphere that led to a full burn-off of organic species (and concomitant MoS2-to-MoO3 transformation, Fig. ). The calculated compositions for samples MoS2-HDA-1 and MoS2-HDA-0.5 are (HDA)0.33MoS2 and (HDA)0.26MoS2, respectively, confirming that the variation of HDA concentration in the precursor solution of the hydrothermal process can control the final composition of pillared MoS2 to some extent.