N-doped TiO2 Immobilized on Nickel Foam and Its Photocatalytic Performance for Formaldehyde Degradation under Visible Light

N-doped nanosized TiO2 powders were directly synthesized by a low temperature hydrothermal method with tetrabutyl titanate as Ti resource and urea as nitrogen resource, and then immobilized on nickel foam substrates. N-doped TiO2 powders were characterized by XRD, SEM, TEM, UV-Vis and XPS. The photocatalytic decomposi- tion property of N-doped nanosized TiO2 to formaldehyde under visible light was investigated. The result shows that nitrogen is incorporated into the TiO2 lattice, so the lattice constants of TiO2 increase (a and c). Nitrogen par- tially substitutes for oxygen and titanium in the TiO2 lattice. The chemical statuses of N can be assigned to Ti−N−Ti and O−N−O in the TiO2 lattice. N-doped TiO2 may be described as Ti1-yO2-xNx+y-TiO2-xNx with its absorbing bound- ary wavelength red shifting to 600nm. N-doped nanosized TiO2 powders can be uniformly dispersed on nickel foam substrates, showing a high photocatalytic decomposition activity to formaldehyde under visible light.