Poly (3, 4-ethylenedioxythiophene) modified polyvinylidene fluoride membrane for visible photoelectrocatalysis and...

A polyvinylidene fluoride (PVDF) organic conductive membrane with photoelectric activity was successfully developed via printing of oxidant (FeCl₃·6H₂O) layer by layer and then chemical vapor deposition (CVD) of Poly (3, 4-ethylenedioxythiophene) (PEDOT). Four kinds of membranes were prepared by changing the number of oxidant coatings layers. The structure and photoelectric properties of four membranes were well characterized. The photocurrent density of 3.7 × 10^-4 A indicated that the four-oxidant coating layers membrane achieved the best performance in photo-electricity activity. A comprehensive study of degradation efficiency under different photoelectric conditions was carried out. Results showed that the photoelectrocatalytic removal of tetracycline hydrochloride was 1.6 and 7.9 times higher than that of photocatalysis and photolysis, respectively, under a voltage of 3 V assisted with visible light irradiation. The anti-interference and stability tests in continuous filtration process demonstrated that the dissolved organic matters (DOMs) can result in a 30% fluctuation on removal rate. The streaming potential tests of DOMs adsorption on membrane surface indicated that the more obvious the adsorption phenomenon was, the degradation of tetracycline hydrochloride was weaker. The degradation intermediates were identified and pathways were proposed in this work. The photoelectrocatalysis of PEDOT modified PVDF membrane provided a new potential for water purification.