Figure 2.

a) Linear‐sweep voltammograms (LSVs) of PEC cells made up of two‐electrode system comprising a photoanode and a Pt counter electrode. b) Incident‐photon‐to‐current conversion efficiency (IPCE) spectra of the PEC cells. No external bias is applied. c) Stability of the Au@CdS‐ZnO PEC cell. Inset is the plot of photocurrent density versus time at a bias of 0.4 V. d) Time courses of H₂ evolution of CdS‐ZnO and Au@CdS‐ZnO PEC cells at a bias of 0.4 V under AM1.5 light irradiation. Aqueous electrolyte composing of 0.25 m Na₂S and 0.35 m Na₂SO₃ was used for all PEC cells with two‐electrode configuration.