Degradation of phenol in industrial wastewater over the F–Fe/TiO_2 photocatalysts under visible light illumination

F–Fe/TiO_2 composite photocatalyst was synthesized by a facile one-step hydrothermal method and then characterized by XRD, XPS and UV–Vis DRS. The catalyst of F–Fe/TiO_2 exhibited the highest photodegradation rate for phenol as compared with pure TiO_2, F/TiO_2, Fe/TiO_2, F0.38–Fe0.13–TiO_2 and Fe(III)/F-TiO_2 under visible light irradiation. The simulated conditions of industrial phenolic wastewater including initial phenol concentration,visible light intensity, p H and different anions were investigated in the presence of F–Fe/TiO_2 photocatalyst. In addition, as expected, the F–Fe/TiO_2 photocatalyst displayed excellent stability, showing a potential industrial application for the treatment of phenolic wastewater.

Sm-doped g-C_(3)N_(4)/Ti_(3)C_(2) MXene heterojunction for visible-light photocatalytic degradation of ciprofloxacin

A heterojunction of Sm-doped g-C_(3)N_(4)/Ti_(3)C_(2) MXene(SCN/MX)was constructed via prepolymerization and solid mixture-calcination method.The modified g-C_(3)N_(4) presented a hollow porous seaweed-like shape which can increase its specific area and active sites.In SCN/MX composite,the optical properties,no matter optical absorption ability or separation performance of photo-induced electrons and holes,were enhanced.Among them,Sm-doping may play an important role on transferring the photogenerated electrons to suppress their recombination,and Ti_(3)C_(2) MXene would broaden light absorption and further improve the carrier migration efficiency.The SCN/MX presented higher photocatalytic degradation efficiency(>99%)of cipro floxacin under visible light irradiation.The quenching experiments and electron spin-resonance spectroscopy confirmed that the dominated active materials were superoxide radical and holes.The degradation mechanisms of ciprofloxacin(CIP)over the SCN/MX were attacking of the active materials on the piperazine ring and quinolone ring,and the final products were CO_(2),H_(2)O and F^(-).

Mesoporous WO_3-graphene photocatalyst for photocatalytic degradation of Methylene Blue dye under visible light illumination

Advanced oxidation technologies are a friendly environmental approach for the remediation of industrial wastewaters. Here, one pot synthesis of mesoporous WO3 and WO3-graphene oxide（GO） nanocomposites has been performed through the sol–gel method. Then, platinum（Pt） nanoparticles were deposited onto the WO3 and WO3-GO nanocomposite through photochemical reduction to produce mesoporous Pt/WO3 and Pt/WO3-GO nanocomposites. X-ray diffraction（XRD） findings exhibit a formation of monoclinic and triclinic WO3 phases. Transmission Electron Microscope（TEM） images of Pt/WO3-GO nanocomposites exhibited that WO3 nanoparticles are obviously agglomerated and the particle sizes of Pt and WO3 are ~ 10 nm and 20–50 nm, respectively. The mesoporous Pt/WO3 and Pt/WO3-GO nanocomposites were assessed for photocatalytic degradation of Methylene Blue（MB） as a probe molecule under visible light illumination.The findings showed that mesoporous Pt/WO3, WO3-GO and Pt/WO3-GO nanocomposites exhibited much higher photocatalytic efficiencies than the pure WO3. The photodegradation rates by mesoporous Pt/WO3-GO nanocomposites are 3, 2 and 1.15 times greater than those by mesoporous WO3, WO3-GO, and Pt/WO3, respectively. The key factors of the enhanced photocatalytic performance of Pt/WO3-GO nanocomposites could be explained by the highly freedom electron transfer through the synergetic effect between WO3 and GO sheets, in addition to the Pt nanoparticles that act as active sites for O2 reduction, which suppresses the electron hole pair recombination in the Pt/WO3-GO nanocomposites.

Heterostructured Nitrogen and Sulfur co-Doped Black TiO2/g-C3N4 Photocatalyst with Enhanced Photocatalytic Activity

Conventional titanium dioxide(TiO2)photocatalyst could absorb only ultraviolet light due to its wide bandgap.In this paper,black TiO2 with narrow bandgap was prepared by introducing oxygen vacancies.Meanwhile.nitrogen(N)and sulfur(S)elements were doped to further broaden the visible light response range of TiOx(NS-BT),and then heterostructured N.S-doped black TiOz/g-C3Na(CN/NS-BT)was successfully constructed by easily accessible route.The formation of CN/NS-BT heteroiunction structure increased the generation and separation efficiency of photogenerated electron-hole pairs,as well as accelerated the transfer rate of the carriers.The as-prepared CN/NS-BT exhibited excellent photocatalytic performance towards the degradation of Rhodamine B(RhB)under visible light irradiation with satisfactory stability.The apparent reaction rate constant of CN/NS-BT(0.0079)was 15.8-fold higher than that of commercial P25(0.0005),The structure,morphology,chemical composition and optical properties of the as-prepared CN/NS-BT were characterized by various analytical methods,and possible photocatalytic enhancement mechanism was proposed.Overall,CN/NS-BT composites look promising as photocatalytic material for future environmental treatment.