Decreased Surface Photovoltage of ZnO Photoanode Films via Optimal Annealing Temperature for Enhanced Photoelectrochemical Performance

Figure 2

(a) Cross-sectional schematic and energy band alignment of the ZnO photoanode for water splitting. Comparisons of PEC properties of four different photoanodes: unannealed ZnO (black), ZnO-350 (blue), ZnO-450 (red), and ZnO-550 (cyan). (b) Linear sweep voltammetry measurements in the dark and under illumination, (c) the corresponding applied bias photo-to-current efficiency as a function of applied potential vs. RHE, and (d) Nyquist plots measured at an applied potential of 0 V vs. Ag/AgCl under illumination. The inset is the equivalent circuit used to fit the Nyquist plots.

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