Visible-light-driven photocatalyst of La–N-codoped TiO2 nano-photocatalyst: Fabrication and its enhanced photocatalytic performance and mechanism

•La–N–TiO2 nano-photocatalyst was fabricated through sol–gel strategy.•The light absorbance of La–N–TiO2 nano-photocatalyst was red-shifted to visible region.•The physicochemical properties of La–N–TiO2 nano-photocatalyst were studied in detail.•The enhanced visible light driven photocatalytic mechanism was proposed and confirmed.

In this study, La, N codoped TiO2 (La–N–TiO2) nano-photocatalyst was fabricated through simple sol–gel method. The resulting samples were characterized through X-ray diffraction (XRD), scanning electrons microscope (SEM), transmission electrons microscope (TEM), X-ray photoelectron spectroscopy (XPS) and UV–visible light diffuse reflection spectroscopy (UV–vis DRS). Results revealed that La elements were not implanted into the structure of TiO2 but existed as the form of TiOLa bonds in the interstitial site, while N dopants were incorporated into the lattice of TiO2 and coexisted in the substitutional N (NTiO) and interstitial N (TiON) in the La–N–TiO2 catalyst, thereby resulting in the formation of new impurity energy level between the forbidden band and greatly enhancement of light absorption ability in visible light region. The enhanced visible light driven (VLD) photocatalytic (PC) performance for the degradation of phenol aqueous solution could be attributed to the intense light absorbance in visible light region and high separation efficiency of photogenerated charge carriers.

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