Visible light responsive titania photocatalysts codoped by nitrogen and metal (Fe, Ni, Ag, or Pt) for remediation of aqueous pollutants

Abstract

Various cation and nitrogen doped and codoped TiO 2 photocatalysts, such as N-TiO 2 , Pt-TiO 2 , N-Fe-TiO 2 , N-Ni-TiO 2 , NAg -TiO 2 and N-Pt-TiO 2 , were prepared by an acid-catalysed sol-gel process. The photocatalysts were characterised by X-ray diffraction (XRD), nitrogen adsorption-desorption isotherms, UV-visible diffuse reflectance absorption spectroscopy (UV-vis DRS), and X-ray photoelectron spectroscopy (XPS). The activities of the photocatalysts were evaluated in photodegradation of phenol solutions under simulated sunlight irradiations. A negative effect of some transition metals (iron and nickel) on photocatalysis was observed on N-metal codoped TiO 2 , while enhancements in photocatalysis from noble metals (silver and platinum) were obtained. N-Pt codoped TiO 2 showed a higher activity under UV-vis irradiations than Degussa P25, with an enhancement of 5.9 times higher. The synergistic effect of N-Pt-codoping was ascribed to the multivalent states of platinum. In addition, photocatalytic activity of N-, Pt-doped and N-Pt-codoped materials were further investigated under visible light irradiations with λ > 430 nm and λ > 490 nm. This study therefore demonstrated a promising strategy for design of highly efficient photocatalysts for remediation of aqueous pollutants.

The influence of Ce doping of titania on the photodegradation of phenol

“…It was found that all samples calcined at 400°C were of anatase phase. Compared to highly crystalline anatase TiO 2 , (103) and (112) crystal faces did not grow very well, which commonly occurred in TiO 2 calcined below 500°C (Sun et al 2013). …”

Nanocarbons in different structural dimensions (0–3D) for phenol adsorption and metal-free catalytic oxidation

“…Pillared clays, zeolites, mesoporous metal oxides, polymers and metal-organic frameworks have shown varying effectiveness in removing toxic pollutants [6]. However, most traditional adsorbents and catalysts are metal-based materials [7][8][9][10] and the demerits of high-cost, scarcity in nature and metal leaching of those materials were experienced [11]. Metal-free carbon materials for adsorption and catalytic oxidation are expected to overcome the issues.…”

Novel polyoxometalate@g-C3N4 hybrid photocatalysts for degradation of dyes and phenolics

“…[4,5] In development of heterogeneous photocatalysis for environmental remediation, metal oxides (TiO 2 , ZnO or Ta 2 O 5 , etc. ), [6,7] metal sulfides (CdS, ZnS or CuS 2 , etc. ), [8] and noble metals (Au, Ag and Pt, etc.…”