Fig. 2: Operando GAXS and quick-XAS characterizations for the OER.

a Schematic illustration of the operando liquid electrochemical cell for the GAXS and quick-XAS apparatus. Operando GAXS of (b) pure Cu2O and (c) H-Cu2O catalysts. d Proposed structural reconstruction during OER. Operando Fourier-transformed EXAFS of (e) pure Cu2O and (f) H-Cu2O catalysts (stages I, II and III are assigned to hydroxylation, oxygen evolution and after OER (potential off), respectively).