Fig. 1: Characterization of Au/CuO nanocubes.
a The schematic diagram showing the fabrication of Au/Cu0 nanocubes using galvanic replacement and the generation of H2O2 and •OH. b UV–Vis profiles of Cu, Au, and different Au/Cu0 nanocubes. c–g TEM images of Cu nanocubes (solid morphology), Au0.02Cu0.98 (with a rough surface), Au0.05Cu0.95 (with slightly hollow appearance), Au0.1Cu0.9 (hollow structure), and Au0.5Cu0.5 (cage-like structure) under galvanic replacement reaction. (One representative data was shown from three independently repeated experiments). h Synchrotron X-ray powder diffraction patterns of Au/Cu0 nanocubes (colored online version). Peaks are indexed as Au (Fm-3m) and Cu (Fm-3m) crystallites. The entire Au(111) region colored under the peak near 40° indicates that the integrated peak areas in these Au/Cu0 nanocubes decrease with decreasing Au content. i and j. XANES spectra for Au L3-edge and Cu K-edge for Au/Cu0 nanocubes including Cu NPs (nanocubes), Cu foil, Cu2O, CuO, and Au foil. k and l Fourier-transformed EXAFS spectra for Au L3-edge and Cu K-edge in Au/Cu0 nanocubes with the solid lines representing best-fit models. Spectra of Au foil and Cu NPs (nanocubes) for comparison. m and o HR-TEM image of the single Au0.02Cu0.98 nanocube and the corresponding atomic ratios in EDS mapping of Cu (red) and Au (cyan). p and q The diffraction pattern and lattice fringe of the Au0.02Cu0.98 nanocube. r AC HAADF-STEM image of the Au0.02Cu0.98 nanocube (red circles indicating Au single atoms). (m–r one representative data was shown from three independently repeated experiments).
