Fig. 2. Characterization of PDA-coated MoO_3–x nanosheets. (a) FT-IR spectrum and (b) survey XPS spectra of PDA-coated MoO_3–x nanosheets. (c) High-resolution XPS of C 1s of PDA and (d) Mo 3d of PDA-coated MoO_3–x nanosheets. (e) XRD patterns and (f) EPR spectra of MoO₃ and PDA-coated MoO_3–x nanosheets.