Fig. 4: The non-covalent interaction between BiVO4 and Cu complexes.
a Uv-vis spectra of BI solutions in MeCN with variable concentration of Cu ions. Inset was the optical image of the solutions. b High wavenumber region and c low wavenumber region in ATR IR spectra of BI solutions in MeCN with variable concentration of Cu ions. d Calculated BDEN−H of BI molecules, Cu-BI complexes and corresponding adsorbed configurations on BiVO4 surface. e Radial distribution functions, g(r), between Cu atom and the N, O, Bi, V atoms. Inset was the representative configurations of Cu-BI complexes on the BiVO4 surface. Cu (orange), N (blue), H (white), C (sky blue), O (red), Bi (pink), V(Gray). f Isosurface plots (s = 0.3) of the RDG for the BiVO4/Cu-BI complexes interfaces. The Multiwfn analysis was based on the equilibrium configuration, without considering polarization effects that may arise from photovoltages. g Schematic illustration of the measured energy diagram at BiVO4/Cu-BI complexes interfaces. The diagram included the conduction band minimum (ECBM), valence band maximum (EVBM), electron quasi-Fermi level (Ee), hole quasi-Fermi level (Eh), and the redox potentials of active species in the Helmholtz layer (Eredox). h Comparison of photovoltage for WOR, BIOR and Cu-assisted BIOR with different Cu ions concentrations. The error bars represented the standard deviations across three parallel experiments.
