Fig. 3: Charge distribution via N-doping strategy.

a High-resolution N 1s XPS spectrum of N–CuO. b Normalized Cu K-edge XANES spectra of N–CuO and its reference samples (Cu foil, Cu2O and CuO). c, d Fourier transform-EXAFS spectra (c) and WT-EXAFS plots (d) from Cu K-edge XANES spectra. e EXAFS fitting analysis of N–CuO at R space. f Schematic optimized atomic coordination model of the N–CuO from EXAFS data.