2 Preparation And Photoelectrocatalytic Performance Composite Graphite / TiO

The combination of TiO2with graphite materials could solve the problem of thehigh recombination of photoinduced charge carriers in the photocatalytic reaction. Inthis thesis, EG/TiO2and Nano-G/TiO2composite were synthesized via a sol-gel method,composites photoanodes were prepared with titanium mesh as a sport. And thephotoelectrochemical properties of photoanodes and photoelectrocatalytic degradationrate of phenol were investigated.The morphology and structures of EG/TiO2and Nano-G/TiO2were characterizedby SEM, TEM, XRD, Raman and FT-IR. The results showed that the anatase phase ofTiO2nanoparticles were dispersed uniformly on the EG and Nano-G, Ti-O-C bondswere formed.The photoelectrochemical properties of EG/TiO2and Nano-G/TiO2wereinvestigated through UV-visible diffuse reflectance spectrum (DRS), electro-chemicalimpedance spectroscopy (EIS) and photocurrent response (PCR). The results showedthat the absorption edge of two types of composite photoanodes could red-shift of15-20nm, and display stronger photoabsorbance over the entire visible light region,compared to bare TiO2photoanode. The resistance of photoanodes significantly reduced.Transient photo generated current of two types of composite photoanodes were10timeshigher than that of TiO2photoanode.Photoelectric catalysis systems were set up with the EG/TiO2and the Nano-G/TiO2photoanode and the titanium mesh cathode. The photoelectrocatalytic mechanism anddegradation rate of phenol were investigated. The results showed that the degradationrate for phenol were94.8%and99.2%, respectively, under the condition of phenolinitial concentration of25mg/L, Na2SO4concentration of0.1mol/L, voltage of2.0V,initial pH of7.0, photoelectrolysis for90min.·OH,·O2-, h+, H2O2played important rolein controlling the photoelectrocatalytic degradation rate of organic matter, and the participation of·OH radicals were mainly responsible for the photoelectrocatalyticreactions.