Visible light activated carbon and nitrogen co-doped mesoporous TiO2 as efficient photocatalyst for degradation of ibuprofen

Schematic diagram illustrating proposed mechanism of visible light activated TiO2 for degradation of low concentration IBF from aqueous solutions; The synergistic effect of the junction between the two crystalline phases enlarge the life time separation of electron-hole pairs for a better photo-catalytic removal of hazardous IBF and the carbon acts as photosensitizer. [Display omitted] •One pot synthesis of (C, N) codoped mesoporous B/A TiO2 was achieved.•Tunable brookite/anatase ratios controlled by glycine.•For first time, codoped B/A was used for complete removed of low conc. Ibuprofen.•The doped samples of B/A was much better than undoped sample under visible light. Carbon and nitrogen co-doped mesoporous TiO2 photocatalysts with tunable brookite/anatase ratios controlled by glycine assistant were synthesized through one-pot hydrothermal process. Structural investigations indicated a formation of pure brookite TiO2 nano-spindles in the absence of glycine, while when glycine was added, mesoporous heterojunction TiO2 nanoparticles consisted of small quasi-spherical anatase and brookite nanorods were obtained. The band gap of the optimum C and N doped TiO2 was 2.85eV, indicated the formation of a visible light-activated photocatalyst. XPS and FT-IR results identified CC, CH and NH bonds, providing clear evidence for doping of nitrogen and carbon into mesoporous TiO2 network. The photocatalytic activity of all prepared catalysts was investigated via photodegradation of ibuprofen (IBF) solutions under visible light and UV illumination. The samples obtained at 74.4% anatase/25.6% brookite heterojunction TiO2 using 1Mglycine exhibited the highest activity, due to its superior properties under visible light illumination with 99% photodegradation efficiency. Moreover, the PL results showed that the e−/h+ recombination rate of the optimal sample was significantly reduced compared to other prepared samples using more or less 1Mglycine content. The improved photocatalytic activity of the optimal sample was attributed to large surface area, heterostructure formation, and high absorption in the visible range and efficient separation of the charge carriers. This study elucidates a facile method for TiO2 synthesis with different mixtures of TiO2 polymorphs with desirable properties for various potential applications.