Preparation And Properties Of Carbon Nitride?g-C₃N₄? Modified Metal Oxide Photocatalyst

In recent scientific research,graphite-like carbon nitride?g-C₃N₄?has attracted more and more attentions because of its strong visible light absorption,high physicochemical stability,easy preparation and nontoxicity.It has been successfully used as high-efficiency visible light catalyst solar water decomposition and organic pollutants degradation.Semiconductor metal oxide materials have been widely used in many areas such as hydrogen production,water pollution control and dye-sensitized solar cells to address solve the growing global crisis in energy and the environment.However,similar to titanium dioxide,zinc oxide and many other semiconductor photocatalysts,the practical application of semiconducting metal oxides as efficient photocatalysts is still limited by the rapid recombination of photo-induced electron-hole pairs and the low efficiency of solar energy conversion.In this paper,we mainly study the design,synthesis route and application results of carbon nitride modified metal oxide photocatalyst.The main contents and conclusions are as follows:1.Using urea as the precursor,the graphite-like carbon nitride?g-C₃N₄?was successfully prepared by calcination method?10?/min,550?,3 h?after treated by three different methods.The results show that the nitrocarbon photocatalyst obtained by the freeze-drying method had the highest activity,and the degradation efficiency for rhodamine B?RhB?was more than 95%after being exposed to visible light for 90 min.2.Using tin tetrachloride pentahydrate and glucose as raw materials,pure phase SnO₂nanospheres were successfully synthesized by hydrothermal method and calcination method,and the most effective carbon nitride prepared by the prepared SnO₂ and freeze-drying method was used as the main raw material.The SnO₂/g-C₃N₄ composite photocatalyst was also prepared by the hydrothermal method.After a series of characterization and analysis,it was proved that the introduction of carbon nitride increased the photocatalytic activity of SnO₂under visible light.The degradation efficiency for RhB after SnO₂/g-C₃N₄?g-C₃N₄ 4 wt%?composite photocatalyst irradiation in visible light for 90 min can reach over 70%?the efficiency of SnO₂ degradation is 30%under the same conditions?.3.Ag₂O/g-C₃N₄ composite photocatalyst was synthesized by liquid precipitation method using silver nitrate,sodium hydroxide and carbon nitride as the main raw materials.After a series of characterization and analysis,it was proved that the introduction of carbon nitride increased the photocatalytic activity of Ag₂O in visible light.The best photocatalytic activity of Ag₂O/g-C₃N₄ is 2 wt%.When the optimum amount of carbon nitride in the system is 2 wt%,the photocatalytic activity of Ag₂O/g-C₃N₄ is the best and the rate can be as high as 98%.