Figure 3From: Facile synthesis and enhanced visible light photocatalytic activity of N and Zr co-doped TiO2 nanostructures from nanotubular titanic acid precursors High-resolution XPS spectra of Ti 2p (a), O 1 s (b), N 1 s (c), and Zr 3d (d) for sample of 0.6% Zr/N-TiO 2 (500). Back to article page