TiO2/C particles as photocatalyst were prepared by dipping TiO2 suspension solution with activated carbon and were applied in the photocatalytic-electrocatalytic degradation of phenol, the Ti/SnO2+Sb2O3/PbO2 electrode and oxygen diffusion electrode were used as anode and cathode respectively, and a 250 W ultraviolet lamp (365 nm) as side light source. The SEM results of TiO2/C and Ti/SnO2+Sb2O3/PbO2 anode indicated that the TiO2 on carbon particles was uniform and PbO2 film on the surface of anode was in cauliflower form, the XRD result of oxygen diffusion electrode showed that only crystalline graphite was found. The influential parameters of degradation process such as applied cell voltage (E), initial concentration of phenol (C0), amount of TiO2 catalyst and air flow rate (v) were discussed. Under the following experimental conditions of C0=50 mg/L, pH=6, E=2 V, TiO2 0.98 mg/mL, v=382.2 mL/min, and light intensity I=10.5 mW/cm2, phenol could be entirely degraded, and about 89% of total organic carbon (TOC) was removed after 3 h degradation.
Two types of Sb-doped SnO2 films on titanium substrate were prepared by the combination of electro-deposition and dip-coating (Ti/SnO2-Sb2O4/SnO2-Sb2O4) and single dip-coating (Ti/SnO2-Sb2O4), respectively. The surface morphology and crystalline structure of both film electrodes were characterized using X-ray diffractometry(XRD) and scanning electron microscopy(SEM). XRD spectra indicate that the rutile SnO2 forms in two films and a TiO2 crystallite exists only in Ti/SnO2-Sb2O4 electrode. SEM images show that the surface morphology of two films is typically cracked-mud structure. The photooxidation experiment was proceeded to further confirm the two electrode activity. The results show that the photoelectrocatalytic degradation efficiency of Ti/SnO2-Sb2O4 electrode with sub-layer is higher than that of simple Ti/SnO2-Sb2O4 electrode using phenol as a model organic pollutant. The Ti/SnO2-Sb2O4/SnO2-Sb2O4 photoanode has a better photoelectrochemical performance than Ti/SnO2-Sb2O4 photoanode for the removal of organic pollutants from water.
