A series of cerium ion-doped titanium dioxide (Ce 3+ –TiO2) catalysts with special 4 f electron configuration was prepared by a sol–gel process and characterized by Brunauer-Emmett-Teller method, X-ray diffraction, X-ray photoelectron spectroscopy (XPS), UV–vis diffuse reflectance spectroscopy (DRS), and also photoluminescence (PL) emission spectroscopy. The photocatalytic activity of Ce 3+ –TiO2 catalysts was evaluated in the 2-mercaptobenzothiazole (MBT) degradation in aqueous suspension under UV or visible light illumination. The experimental results demonstrated that the overall photocatalytic activity of Ce 3+ –TiO2 catalysts in MBT degradation was signigicantly enhanced due to higher adsorption capacity and better separation of electron-hole pairs. The experimental results verified that both the adsorption equilibrium constant (Ka) and the saturated adsorption amount (Gmax) increased with the increase of cerium ion content. The results of XPS analysis showed that the Ti 3+ ,C e 3+ , and Ce 4+ ions reside in the Ce 3+ –TiO2 catalysts. The results of DRS analysis indicated that the Ce 3+ –TiO2 catalysts had significant optical absorption in the visible region between 400 and 500 nm because electrons could be excited from the valence band of TiO2 or ground state of cerium oxides to Ce 4 f level. In the meantime, the dependence of the electron-hole pair separation on cerium ion content was investigated by the PL analysis. It was found that the separation efficiency of electron-hole pairs increased with the increase of cerium ion content at first and then decreased when the cerium ion content exceeded its optimal value. It is proposed that the formation of two sub-energy levels (defect level and Ce 4 f level) in Ce 3+ –TiO2 might be a critical reason to eliminate the recombination of

for 2-mercaptobenzothiazole degradation in aqueous suspension for odour control

The new Introduction to Environmental Engineering and Science covers the basics needed to understand technology, manage resources, control pollution, and successfully comply with the regulations. Thoroughly updated and expanded, this edition features a new chapter and new coverage on risk and uncertainty analyses; hydrology; basic principles of soil science, soil erosion, and sedimentation; mining; and policies, programs, and the latest status reports on key environmental issues.

Introduction to Environmental Engineering and Science

Organic pollutants removal in wastewater by heterogeneous photocatalytic ozonation

Improvement in concrete resistance against water and chloride ingress by adding graphene nanoplatelet

Photocatalytic air cleaners and materials technologies – Abilities and limitations

Resistance of high-performance fiber-reinforced cement composites against high-velocity projectile impact

Metal-ions doped TiO 2 (M-TiO 2 ) were synthesized using a hydrothermal method with a post-annealing process, including individual Ag + , Cu 2+ , Mn 2+ , Ce 3+ , Fe 3+ and Zr 4+ ions. Physical properties of the synthesized M-TiO 2 were characterized including XRD pattern, BET surface area, diffuse reflectance spectra and visible-light photoactivity tests. Total photocatalytic performances of M-TiO 2 were evaluated by degrading rhodamine b under whole solar-light irradiation with manganese-ions doped TiO 2 (Mn-TiO 2 ) showing the highest degradation efficiency. Compared to crystalline structure and visible-light photoactivity, BET surface area of M-TiO 2 particles exhibits the most significant impacts, showing a positive correlation with the total photocatalytic performance of M-TiO 2 . Total photocatalytic efficiencies of Mn-TiO 2 were further optimized through synthesis with 3% of Mn doping concentration, 180 °C of hydrothermal treatment and 450 °C of post-annealing temperature.

Huajun Feng

Papers

Resistance of high-performance fiber-reinforced cement composites against high-velocity projectile impact

Hydrothermal synthesis and photocatalytic performance of metal-ions doped TiO2

Effects of silanes and silane derivatives on cement hydration and mechanical properties of mortars

Photocatalytic degradation of particulate pollutants and self-cleaning performance of TiO2-containing silicate coating and mortar

Ultrasonic synthesis and photocatalytic performance of metal-ions doped TiO2 catalysts under solar light irradiation