Photocatalytic Si nanowires/TiO ₂ microparticles with extended absorption edge up to 700nm

Single-crystalline Si nanowires are fabricated by Ag-assisted chemical etching at room temperature. On the basis of efficient light harvesting of Si nanowires, the novel photocatalysts are prepared by mixing the as-prepared Si nanowires with TiO ₂ microparticles of various weight ratios. The dye degradation of these combined photocatalysts is above two times more efficient than conventionally used TiO ₂ under 580nm light irradiation. We have also validated that the involving photodegradation agrees well with the first-order kinetic model. These photocatalysts possess broad-band absorption with extended edge up to 700nm, facilitating high photocatalytic activity for the urgent treatment of water pollutants.