Photocatalytic degradation of methyl orange over monoliths of (m)PTM0, (n) PTM1, (p) PTM2, (q) PTM3 under visible light (a) and full spectrum (b) irradiation.

MO specific removal efficiency (SRE) over PTMx under full spectrum irradiation (a1) and visible light irradiation (a2).

XRD patterns of PTM3 and PTM0.

TEM image of PTM3 with magnification of 50000×.

BJH pore size distribution plots and N2 adsorption–desorption isotherms (inset) of PTM3 and PTM0.

Typical SEM images of PTM3 calcined at 350°C with magnification of 1000× (a); with magnification of 5000× (b).

UV-vis absorption spectra of PTM3.

XPS spectra for PTM3: (a) Ti2p, (b) O1s, (c) C1s, and (d) N1s.

Cycling runs in photocatalytic degradation of methyl orange (insets are the digital pictures of the PTM3 before and after four cycling tests).

Figure 1 XRD patterns of a) neat CdS nanowires and of b) nanoparticles-modified 1D CdS@TiO2 core-shell heterostructure. The stick spectral represent the standard reflections of anatase TiO2 and hexagonal CdS.

Figure 2 a) TEM and b) high-resolution TEM images of nanoparticles-modified 1D CdS@TiO2 core-shell heterostructure.

Figure 3 TEM images of a) nanolayer-modified 1D CdS@TiO2 core-shell heterostructure and d) TiO2 nanotubes. High-resolution TEM images of b) TiO2 shell and c) CdS core of the rectangular region in a). e) SAED pattern of the heterostructure

Figure 4 XRD pattern of pure CdS nanowires annealed at 500 °C for 3 h in air atmosphere.

Figure 5 UV-vis absorption spectral of (a) neat CdS nanowires, and (b) nanoparticles-modified 1D CdS@TiO2 core-shell heterostructure.

Figure 6 a) Absorption spectrum changes of MB aqueous solution (15 mg/L) degraded by nanoparticles-modified 1D CdS@TiO2 core-shell heterostructure with irradiation time: 0, 1, 2, and 3 h, b). Visible-light photodegradation of MB under different conditions. Curves: (1) over nanoparticles-modified 1D CdS@TiO2 core-shell heterostructure, (2) over neat CdS nanowires, (3) over nanolayer-modified 1D CdS@TiO2 core-shell heterostructure and (4) no catalyst.

Figure 7 Diagram of photogenerated charge carriers transmission on nanoparticles-modified 1D CdS@TiO2 core-shell heterostructure.