CdS and SnS2 nanoparticles co-sensitized TiO2 nanotube arrays and the enhanced photocatalytic property

• Low deposition concentration can deposit CdS and SnS2 and keep the nanotubular structures.
• SnS2 and CdS can improve the absorbing capability of TiO2 NTs for the visible light.
• The band gap of SnS2/CdS/TiO2 NTs is 1.95 eV.
• SnS2 and CdS nanoparticles are conducive to improve the photocatalytic efficiency.
• The photocatalytic mechanism of SnS2/CdS/TiO2 NTs to methylene blue is reasonable and concise.

TiO2 nanotube arrays co-sensitized with SnS2 and CdS nanoparticles (SnS2/CdS/TiO2 NTs) were successfully fabricated by SILAR method. The as-synthesized SnS2/CdS/TiO2 NTs were characterized with X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), energy dispersive spectrometer (EDS) and ultraviolet-visible (UV–vis). Their photocatalytic activities have been investigated on the degradation of methylene blue under simulated solar light irradiation. XRD results indicate that TiO2 NTs were mainly anatase phase, SnS2 and CdS were highly crystallized. FESEM results indicate that TiO2 NTs can keep the nanotubular structures at low deposition concentration. UV–vis results indicate that SnS2 and CdS can be used to improve the absorbing capability of TiO2 NTs for the visible light. And the band gap of SnS2/CdS/TiO2 NTs is 1.95 eV. Photocatalytic results indicate that SnS2 nanoparticles are conducive to improve the photocatalytic efficiency. And the highest degradation rate to methylene blue of SnS2/CdS/TiO2 NTs is 94.5%. At last, the photocatalytic mechanism of SnS2/CdS/TiO2 NTs to methylene blue is also described.

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