Figure 3: Comparison of PEC performance.

(a) Photocurrent-potential (J–V) curves of undoped, W-doped, C-doped and (W, C)-codoped TiO₂ NWs measured in a three-electrode setup (TiO₂ working, Pt-wire counter, SCE reference electrode, scan rate of 50 mV s⁻¹) and 1 M KOH electrolyte under simulated solar light illumination (AM 1.5 G, 100 mW cm⁻²). (b) The photocurrent density-time response shows good stability of TiO₂:(W, C). (c) IPCE spectra measured at 1.23 V versus RHE. The inset shows a magnified view in the wavelength region of 400–500 nm.