Hole annihilation vs. induced convection: Breakdown of different contributions to the photocorrosion mechanism of oxide-covered iron

• Illumination increases the dissolution rate of oxide covered iron. The behaves as n-type semiconductor with direct band gap 1.9–2.1 eV. Electron–hole pair formation enhances by hole annihilation. Induced convection and thermal effects in also increase corrosion rate. Contributions from three light on photocorrosion iron are quantified. mechanism behind anodised under illumination has been studied comparing photocurrents currents polarisation curves controlled convection. Under photon energies larger than ∼2 eV, current densities increased maximum 30%, triggered largely annihilation through cation dissolution. Thermal play a role. Photocurrent measurements indicate little upward bending, fluctuations, at open circuit. contributions different mechanisms to have quantified, relevant for steels photoelectrochemical water splitting.