Photoelectrochemical Degradation Organic Pollutant And Generation Hydrogen By Modified TiO₂ Nanotubes Arrays

Photocatalyis is a new and effective technology to treat environmental pollution(eg. Organic pollutants). Nanosized Ti O2 was extensively studied due to its excellent photocatalytic activity. The most important focus has been on their provement of efficiency of utilizing solar energy and photocatalytic activity. Non-metal-doping can increase utilization of visible-light activity and photoelectrochemical(PEC) system is an efficient process to improve photocatalytic activity of Ti O2.This study applies anodization and chemical deposition method to synthesize carbon and nitrogen co-doped Ti O2 nanotube arrays. FESEM, XRD, XPS and UV-vis spectroscopy were conducted to characterize the obtained C-N-TNTAs. PEC degradation of hazardous organic compounds was exemplified by Methyl Orange(MO) and PFOA, in the anode, while hydrogen generation in the cathode. Concurrent PEC reduction of H2 O and oxidation of MO were conducted by applying C-N-TNTAs. XRD results show that C-N-TNTAs primary phase is anatase but not rutile and with a high crystallinity; FESEM image shows that the order nanotube arrays structure had not damaged after carbon and nitrogen doped; The light response range can be broaden by doping treatment from UV-vis result; XPS result proved that carbon and nitrogen atom was successfully doped into the TNTAs. The characterization results show that carbon and nitrogen atom was successfully doped into the TNTAs and broaden the range of light response while without disturbing the order nanotube arrays structure. C-N-TNTAs has a high photocatalytic degradation efficiency and removal 5 mg/L MO 100% in 30 min in the photoelectrochemical system. A high hydrogen generation efficiency also obtain by C-N-TNTAs phtoelectrochemical water reduction(2.66 mmol/h), which concurrent at PFOA degradation. Electrochemical analysis result show that the probality of recombination of electron-hole pair can be reduced by applying the bias potential in PEC system. The larger of the bias potential, the higher of photoelectrochemical activity. Thus, this experiment system may have an excellent applicable prospect in PEC degradation of organic pollutants and hydrogen generation concurrently.