Fig. 1: Synthesis and structural characterization of Aux-CN photoelectrode.

a Scheme of the general fabrication procedure for CN and Aux-CN on the FTO. b STEM and c HAADF-STEM images of Aux-CN. Inset of b: HRTEM image of Aux-CN. Isolated bright spots highlighted by a white circle: Au single atom. d XRD patterns of CN and Aux-CN. The asterisk indicates the diffraction from Au nanoparticles. “a.u.” refers to arbitrary units. e Fourier transforms of the EXAFS spectra of Aux-CN and the reference samples.