fig2

Figure 2. Characterizations of the reconstructed catalysts. (A and B) In situ XRD patterns of CuO-MoS₂/MoO₃ during HER process; (C and D) In situ XRD patterns of CuO-MoS₂/MoO₃ during OER process; AC-STEM images of (E) Cu-MoS₂ and (F) CuO-MoS₂/MoO₃ after reaction; XPS spectra of (G) Cu 2p, (H) Mo 3d, (I) S 2p, and (J) O 1s in Cu-MoS₂ and CuO-MoS₂/MoO₃.