Pd-TiO2/ITO films were prepared by a dip-coating and subsequent photo-deposition procedure. The Pd-TiO2/ITO film was well characterized by X-ray diffraction, scanning electron microscope and open circuit voltage. It was found that the Pd-TiO2/ITO film not only possessed higher photocatalytic and photoelectrocatalytic activities, compared with bared TiO2/ITO film, but also showed a certain non-photocatalytic activity towards HCOOH degradation at room temperature and atmosphere pressure. This is the first report about versatile catalytic activities of Pd-TiO2 film.

The removal of chemical oxygen demand (COD) from wastewater-containing phenol was investigated using threephase three-dimensional electrode reactor. Special attention was paid to experimentally probe the performance of the reactor in COD removal in the process of repeated batch runs. The experimental results showed that the reactor could remove COD from phenol-containing wastewater much more efficiently than both granulated activated carbon (GAC) adsorption bed and conventional three-dimensional electrode. For 200th batch run, the three-phase three-dimensional electrode reactor with an airflow of 5 1min-1 and a cell voltage of 30 V could remove 1350 ppm COD from the wastewater in 30 min while conventional three-dimensional electrode reactor with a same cell voltage and GAC adsorption bed with a same airflow only could remove 610 and 1000 ppm, respectively, at the same reaction duration. Although it was found that COD removal decreased with increasing repeated batch runs in our experimental range, due to adsorption saturation of GAC and electrode passivation, the extent of decrease for the three-phase three-dimensional electrode is much less than those for conventional three-dimensional electrodes and GAC adsorption beds. The passivated reactor could be partly re-activated by electrolysis in the presence of MnO2.

Ag-TiO2 composite film was supported on indium–tin oxide glass (ITO) by a dip-coating and subsequent photodeposition procedure. The composite film was characterised by UV-Vis diffuse reflectance spectra, X-ray reflection diffraction (XRD) spectra, scanning electron microscope (SEM) and photoelectrochemical measurement. Itwas used as a photoanode in a two-compartment photoelectrochemical cell to investigate the feasibility of a hybrid technology of Ag deposition combined with the application of an external electric field. The experimental results show that the combination has an apparent additive effect with respect to suppressing the recombination between the photogenerated charge carriers and enhancing the photoelectrocatalytic (PEC) oxidation of formic acid. A primary approach to a pulse PEC technology presents the possibility that the Ag-TiO2/ITO film electrode is performed at an anodic bias over the oxidation potential of the deposited Ag.

The application of a small anodic bias can promote the photocatalytic oxidation of formic acid on Cu-TiO2 film. However, the photocatalytic activity was not stable at higher anodic biases or in the process of repeated use due to the electrochemical oxidation of Cu. A new photocatalytic technology with a pulse anodic bias was proposed to tackle the deficiency of the Cu-TiO2 film. It was found that the photocatalytic technology could not only overcome the Cu oxidation but also increased the photocatalytic activity of the Cu-TiO2 film.

Deeolourization and COD removal fm synthetic wastewater containing Reactive Btilliant Orige K-R (RBOKR) dye using sonophotoeatalydc technology was investigated. Experimental results showed that this hybrid technology could eflleiently remove the eolour and aduce COD from the synthetic dye-cont aining wastewater, and that both processes fonowed pseudo first-order kinetics. At the condition of 0.1 m3 h-I airflow, 0.7S gdm-3 titanium dioxide and 0.5 mmol dm 3 RBOKR solution, the rate constants of decolourlzation and COD removal we 0.0750 d 0.0143 min-1 respectively for the sonophotoeatalytic process; 0.0197 d 0.0046 min respectively for the phot at Mytic process and 0.000S and 0.0001 min J respectively for the sonochieal process. The rate constants of sonophotocatalysis were greater than that of both the photocatalytic and sonochemical processes either in isohtion or as a sum of the individual prcess, indicating an appannt synergetic effect heeen the photo-and sono-processes.