Optical near-field induced visible response photoelectrochemical water splitting on nanorod TiO2

Here we report a way to induce the visible response of non-doped TiO2 in the photocatalytic electrochemical water splitting, which is achieved by utilizing the optical near-field (ONF) generated on nanorod TiO2. The visible response is attributed to the ONF-induced phonon-assisted excitation process, in which TiO2 is excited by sub-bandgap photons via phonon energy. Our approach directly gets involved in the excitation process without chemical modification of materials; accordingly it is expected to have few drawbacks on the photocatalytic performance. This study may offer another perspective on the development of solar harvesting materials.