Figure 4

Schematic diagram and photocurrent response of P25 control, CdSe/P25, H-TiO₂ and CdSe/H-TiO₂ under AM 1.5 illumination (100 mW/cm²).

(a) Schematic diagram showing the hydrogen generating mechanism of CdSe/H-TiO₂. (b) Linear sweep voltammetry measurements of P25, p-P25, P25/st-TIO and H-TiO₂ under UV-visible and dark conditions. (c) Linear sweep voltammetry measurements of CdSe/P25 and CdSe/H-TiO₂ under UV-visible, visible light illumination and dark conditions. (d) J-t curves of CdSe/H-TiO₂ at a bias of 0.5 V under UV-visible and visible light illumination. (e) EIS response of P25 and H-TiO₂. The measurement was conducted at a frequency range from 100 kHz to 0.1 Hz under open circuit voltage conditions. (f) Measurement of the incident photon-to-electron conversion efficiency. All experiments were performed with a 0.24 M Na₂S and 0.35 M Na₂SO₃ electrolyte (pH = 12) and 100 mW/cm² xenon lamp coupled with a UV/IR filter as the light source.