Preparation and characterization of C,N-codoped TiO2 photocatalyst for the degradation of diclofenac from wastewater

Abstract

Application of mesoporous C- and C,N-codoped TiO2 in the removal of diclofenac from water was studied. The sol-gel method was used for the preparation of the photocatalysts. The physicochemical properties of studied materials were characterized by BET (Brunauer, Emmett and Teller), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy and X-ray diffraction (XRD) methods. XPS confirmed the incorporation of nitrogen and carbon atoms into TiO2 lattice. The synthesized catalysts were effective in the removal of the studied pollutant from water and enabled reduction of the COD (chemical oxygen demand) value of the wastewater by at least 60%. The process of diclofenac photooxidation over the C,N-codoped and C-doped TiO2 photocatalysts proceeded similarly and was followed by pseudo-first order kinetics. The increase in calcination temperature resulted in the rutile fraction (5%) slightly lowering the effectiveness of treatment. The results over pure anatase structures confirmed that anatase has usually a better photocatalytic activity than rutile. The best changes in the water quality were observed during the first 50 min of treatment, but mineralization of pollutant did not lead to complete.

Study of nitric oxide degradation properties of photoactive concrete containing nitrogen and/or carbon co‐modified titanium dioxide – preliminary findings

“…13–20%), containing N and/or C‐modified TiO 2 additives, is believed to be connected with the presence of the non‐metals in the TiO 2 structure. The higher photocatalytic activity of such modified photocatalysts was confirmed in the variety of photocatalytic oxidation processes [24–27] and ascribed to the formation of additional energy states in TiO 2 lattice. As presented in Table 2, the TiO 2 /N and TiO 2 /N,C photocatalysts displayed similar amounts of N, which might explain an almost identical NO (and NO x ) conversion on the Con + TiO 2 /N and Con + TiO 2 /N,C materials.…”

Removal of Pharmaceutical Contaminants in Wastewater Using Nanomaterials: A Comprehensive Review

“…Co-doping may increase OHgroups on to the surface of nano-TiO 2 improving the stability of desired defects in TiO 2 crystal lattice and reducing the photo-generated electron hole pair recombinations [222,223]. For example, Buda and Czech et al (2013) achieved an effective (80%) degradation of diclofenac in wastewater by using carbon/nitrogen co-doped TiO 2 [224]. Segne et al (2011) [225] evaluated the photocatalytic degradation of pharmaceuticals using Mg +2 /Cu +2 co-doped TiO 2 which showed shifts in the absorbance band from UV to visible region reducing the band gap energy from 3.2 eV to 2.50 eV.…”

CdS quantum dots modified N-doped titania plates for the photocatalytic mineralization of diclofenac in water under visible light irradiation

“…Many publications have demonstrated that DCF can be decomposed due to the photocatalysis of TiO 2 [6][7][8][9][10]. Unfortunately, to our knowledge, only UV and near UV-Visible (366 nm) light were used to excite the photocatalytic decomposition of DCF so far [6][7][8][9][10], due to the restrictive light absorption of TiO 2 resulted from its wide band-gap [11]. From the viewpoint of utilizing solar light, visible light responsive TiO 2 photocatalysts with high activity for the decomposition of DCF are highly desired.…”