Preparation And Photocatalytic Property Of N-doped TiO₂/Biochar

With the rapid development of the food industry and personal care products industry in China,paraben which are toxic bring great impact to our environment and human body.Therefore,it is urgent to find a new type of photocatalytic material with high efficiency,low cost and good performance to remove paraben.Because of the photocatalytic ability,low cost and chemical stability and non-toxic,titanium dioxide?TiO₂?are widely used.However,due to the large band gap of TiO₂,it can only produce photocatalytic effect under ultraviolet light irradiation,which limits the use of solar energy and industry of TiO₂.At the same time,the TiO₂ powder are difficult to recycle,so it needs to be loaded with suitable carrier to adapt to large-scale practical applications.Biochar?BC?owns good physical and chemical properties.BC can easily combine with TiO₂ to form a composite.In this paper,nitrogen-doped and biochar were used to improve the photocatalytic activity of TiO₂,so as to prepare photocatalytic materials that have good photocatalytic activity and are conducive to recovery.They also efficiently utilize solar energy and are suitable to large-scale practical applications.In this paper,the mechanism of photocatalytic degradation of EP using TiO₂ was studied by adding BC.The impact factors included weight ratio of BC to TiO₂,temperature and p H were investigated consecutively.The fourier infrared spectroscopy and scanning electron microscope indicated that the functional groups decreased and agglomeration increased of BC with the rise of temperature.It was conducive to the charge transfer.BC,rougher surface and smaller pore,is favorable for the adsorption of pollutants.The 42.5% removal of EP was obtained at BC to TiO₂ ratio of 10%,temperature 500°C,p H 9,irradiation time of 120 min.The combination of BC and TiO₂ improved the removal efficiency of EP compared with pure TiO₂,but the increase was not obvious.Because simple mixing did not fully exert the effect of BC.The BC/TiO₂ composites were made by sol-gel method.The photocatalytic activity of samples was assessed by photodegradation of EP.At the same time,the effects of weight ratioof BC to TiO₂,calcination temperature and p H were disscussed.Structure characteristics analysis of samples were measured by X-ray diffractometer,Diffuse reflectance UV-visible absorption spectra,Scanning electron microscope and Brunauer-Emmett-Teller.The results showed that the TiO₂ particles were evenly distributed on the BC and the particle size of the composites was reduced.The spectral absorption range of the composites was extended from the ultraviolet region to the visible region.The 73.1% removal of EP was obtained at BC to TiO₂ ratio of 5%,temperature 500°C,p H 5,irradiation time of 120 min.Pseudo-first order kinetic model could well describe the photocatalytic degradation of EP.The composites of BC and TiO₂ could effectively improve the photocatalytic performance of TiO₂,and the composites exhibited good reusability.The nitrogen-doped BC/TiO₂ composites were prepared by sol-gel method.The photocatalytic activity of samples was assessed by photocatalytic degradation of EP.At the same time,the effects of weight ratio of BC to TiO₂,calcination temperature and p H were disscussed.The results showed that the incorporation of N into TiO₂ particles could restrain the agglomeration of TiO₂ particles and reduced the band gap.It also greatly improved the absorption of visible region and the specific surface area of the composite.The 91% removal of EP was obtained at BC to TiO₂ ratio of 3%,temperature 500°C,p H 5,irradiation time of 120 min.Pseudo-first order kinetic model could well describe the photocatalytic degradation of EP.The Nitrogen-doped could improve photocatalytic performance of the composites,and the composites exhibited good reusability.It was expected to be widely used in wastewater treatment.