Effective visible light-active boron and carbon modified TiO2 photocatalyst for degradation of organic pollutant

A visible light-active TiO2 photocatalyst modified by boron and carbon was synthesized by sol–gel followed solvothermal process. The resulting photocatalyst was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), UV–vis absorption spectroscopy, and electron paramagnetic resonance (EPR). It was found that the boron and carbon modified TiO2 showed obvious absorption in the range 400–500 nm. XPS results suggested boron species entered into interstitial site of TiO2 matrix and formed the B–O–Ti bond, while carbon species were in the form of carbonates species. EPR results showed the existence of oxygen vacancy in carbon and boron modified TiO2. This may result in the sensitivity of the as-synthesized photocatalyst to visible light. The resulting boron and carbon modified TiO2 exhibited significantly higher photocatalytic activity than carbon modified TiO2 and undoped anatase TiO2 on the degradation of Acid Orange 7 (AO7) in aqueous solution under visible light irradiation. The presence of carbon originating from organic precursor has great influence on the surface properties of B-doped TiO2.