Yue Situ

Construction of Heterostructured g-C3N4/Ag/TiO2 Microspheres with Enhanced Photocatalysis Performance under Visible-Light Irradiation

The visible-light photocatalytic performance of the heterostructured g-C3N4/Ag/TiO2 microspheres was investigated. As an electron-conduction bridge, Ag nanoparticles were photodeposited as the interlayer between g-C3N4 and the surface of TiO2 microspheres to increase visible-light absorption via the surface plasmon resonance. The interface between Ag/TiO2 and g-C3N4 facilitates the direct migration of photoinduced electrons from g-C3N4 to Ag/TiO2, which is conductive to retarding the recombination of electron-holes. The g-C3N4 (4%)/Ag/TiO2 microsphere sample shows significant photocatalytic activity, higher than the sum of g-C3N4 (1.2 mg) and Ag/TiO2 samples, or the sum of TiO2 and Ag/g-C3N4 (1.8 mg) samples. It indicates that the heterostructured combination of g-C3N4, Ag and TiO2 microspheres provides synergistic photocatalytic activity through an efficient electron transfer process.

Facile synthesis of the Ti 3+ –TiO 2 –rGO compound with controllable visible light photocatalytic performance: GO regulating lattice defects

AbstractVisible light photocatalytic Ti3+–TiO2–rGO compound with controllable photocatalytic performance was prepared by a one-step microemulsion method, via altering the amount of lattice defects in TiO2. A facile method for regulating Ti3+ doping concentration and the lattice defects was obtained based on the aggregation effect of the positively charged Ti species on GO surface in the micelles. Raman and X-ray photoelectron spectroscopy were used to confirm the existence of Ti3+ and rGO in the self-doped samples and electron spin resonance (ESR) was adapted to semi-quantitatively analyze the relationship between lattice defects and the amount of GO added. It was found that the ESR signal rose progressively in intensity with the increase in the amount of GO addition, indicating that GO could regulate the lattice defects existed in the compound. A possible regulating and enhancing mechanism of visible light photocatalytic activity for self-doped Ti3+–TiO2–rGO was also proposed.

In-situ growth of lepidocrocite on Bi2O3 rod: A perfect cycle coupling photocatalysis and heterogeneous fenton-like process by potential-level matching with advanced oxidation

γ-FeOOH was grown in situ on the surface of rod Bi2O3 to construct a perfect cycle coupling photocatalysis and heterogeneous Fenton-like process. The degradation efficiency of this system was detected under the irradiation of visible light. γ-FeOOH/Bi2O3 showed better degradation efficiency than pure Bi2O3 and γ-FeOOH, and the amount of TOC was decreased to 4.3, suggesting that the system exhibits outstanding oxidation ability that MO and phenol could be degraded to CO2 and H2O totally. PL spectra, trapping experiments and ESR test were also carried out to confirm the mechanism of photocatalysis with heterogeneous Fenton-like process, and the suitable conduction band (CB) of Bi2O3 matches the electric potential of iron ions was proved to be the key to keep the perfect cycle. Then optimal concentration of H2O2, the effect of pH and the stability of the photocatalyst were also investigated.