•An oxygen-vacancy-rich Z-scheme BCN-TiO2 were prepared by a calcination method.•BCN-TiO2 showed the higher visible-light photocatalytic H2 production activity.•The formation of oxygen vacancy can enhance visible light absorption of BCN-TiO2.•Interaction between BCN and TiO2 promoted charge transfer due to oxygen vacancies.BCN-TiO2 nanocomposites are obtained by a simple calcination method using a hexagonal boron carbon nitride (BCN) semiconductor and nanotubular titanic acid (NTA) as precursors. The BCN-TiO2 nanocomposites are characterized systematically by XRD, TEM, XPS, DRS, ESR, BET, I-t and PL techniques. Compared with the novel TiO2 or single BCN sample, the BCN-TiO2 nanocomposites prepared by a calcination method show the highest photocatalytic activity for hydrogen production under visible-light irradiation. The photocatalytic activity of BCN-TiO2 nanocomposites is optimized by changing the amount of BCN. Characterization results confirm that a large amount of single electron oxygen vacancies can be formed when NTA was calcined at the higher temperature, which is beneficial to the enhancement of visible light absorption and the transfer of photogenerated carriers due to the formation of ohmic contact at the interface between BCN and novel TiO2. Therefore, the visible light photocatalytic activity for H2 production of BCN-TiO2 nanocomposites has been improved significantly by the formation of BCN-TiO2 Z-scheme photocatalyst, which results in efficient space separation of photo-induced charge carriers.

Zr/N co-doped TiO2 nanostructures were successfully synthesized using nanotubular titanic acid (NTA) as precursors by a facile wet chemical route and subsequent calcination. These Zr/N-doped TiO2 nanostructures made by NTA precursors show significantly enhanced visible light absorption and much higher photocatalytic performance than the Zr/N-doped P25 TiO2 nanoparticles. Impacts of Zr/N co-doping on the morphologies, optical properties, and photocatalytic activities of the NTA precursor-based TiO2 were thoroughly investigated. The origin of the enhanced visible light photocatalytic activity is discussed in detail.

In this paper, we report on the co-doping nitrogen and sulfur has been achieved in the TiO2 nanotube array films by treatment with thiourea and calcination under vacuum at 500 °C for 3 h. The samples were characterized by scanning electron microscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and ultraviolet–visible diffuse reflectance spectroscopy. XPS spectra revealed that N might coexist in the forms of NTiO and NOTi, S was incorporated into the lattice of TiO2 through substituting oxygen atoms in the N + S co-doped TiO2 nanotube array films. XRD patterns indicated that improved crystallinity was obtained for N + S co-doped TiO2 nanotube arrays as compared to that of undoped TiO2 nanotube arrays. In photoelectrochemical measurements, the photocurrent of N + S co-doped TiO2 nanotube array films was greatly enhanced compared to that of undoped samples under visible light irradiation. And the photocatalytic activities of the samples were evaluated on the removal of methylene blue under visible light irradiation. The N + S co-doped TiO2 nanotube array films showed a better photocatalytic activity than the undoped sample due to the N, S doping.