The pronounced diffraction fringe o

The pronounced diffraction fringe of the HRTEM image (inset of Fig. 3f) showed d-spacings of 0.246 and 0.213 nm, corresponding to the (1 1 1) and (2 0 0) facets of cubic Cu 2 O, respectively.[36,37] To further explore the detailed elemental distributions, energy-filtered W, Cu, and O maps of the Cu 2 O/WO 3 -001 sample were constructed and shown in Fig. S3. As can be seen, all the elements were homogenously distributed, indicating that Cu 2 O was uniformly deposited on the surface of WO 3 nanosheet by the electroreduction method.