Experimental Study On Photodegradation Of Phenolic Organic Pollutants In Water

Development of a suitable in-situ remediation technology for surface water purification is an attractive issue in environmental geochemistry area,which possesses significance in both theoretical research and practical application.Photocatalysis is a green,efficient,sustainable,environmental purification technology which can decompose organic pollutants completely.Currently,P25powder has become commercially available.But defects of P25,such as limitation of recyclability and photocatalytic activity,hindered it's practical application.Therefore,in this paper,advanced photocatalysts were synthesized for in-situ degradation of bisphenol A,which is a common organic pollutants in surface water.The photocatalytic mechanism was carefully investigated.The results are shown as follows:?1?Sheet-like BiOI/TiO₂ photocatalysts with size of 2 cm were synthesized by using electrospinning and hydrothermal method.As-prepared photocatalysts exhibited enhanced activity for methyl blue degradation.Besides,photocatalysts could be recovery because it's large-scale morphology.Basic physicochemical properties of photocatalysts were carefully investigated.Photocatalytic degradation mechanism was elucidated by using electron spin resonances,XPS valence band spectra,PL spectra and electrochemistry work station.The results showed that the enhancement of photocatalytic activity was attributed to high production of free radicals,which related to the exposed reactive facet,manipulation of heterostructures and efficient charge transfer behavior.?2?Bi OI semiconductor with deposited Bi nanoparticle was synthesized by using hydrothermal method,which could achieve oxygen vacancies and enhance charge transfer capacity.As-prepared photocatalysts showed enhanced photocatalytic activity under the irradiation of visible light.Bisphenol A was employed as probe molecular to evaluate the photocatalytic activity.In the 10 mg/L bisphenol A solution containing 1g/L photocatalysts,86%of bisphenol A was decomposed after 4 hours irradiation of visible light.The decomposition pathway of bisphenol A was investigated by using ESI-MS,and results showed that the bisphenol A was decomposed completely into water and carbon dioxide.In this paper,two types of advanced photocatalysts were synthesized,that is the BiOI/TiO₂ heterostructures and BiOI semiconductor photocatalysts.As-prepared photocatalysts could utilize visble light for in-situ remediation of organic pollutants in surface water.