چكيده به لاتين
In this study, the synthesis and investigation of the photocatalytic properties of g-C3N4 @TiO2 nanocomposites were carried out. The aim of this study was to increase the photocatalytic properties of graphitic carbon nitride and TiO2. For this purpose, the g-C3N4@TiO2 nanocomposite was synthesized for the first time by a new, simple and single-step method (physical mixing). Also, to compare the photocatalytic properties of the synthesized samples, another method was used to synthesize the nanocomposites. In this method, graphitic carbon nitride was first synthesized from the melamine precursor by thermal pyrolysis. In order to improve the photocatalytic properties of g-C3N4, exfoliation was performed by two thermal and chemical methods. Then, TiO2 nanoparticles were synthesized by sol-gel method. The g-C3N4/TiO2 nanocomposite with heterogeneous bonding structure was synthesized by sol-gel method. XRD, FTIR, UV-VIS, PL, BET and FESEM tests were used to characterize the synthesized samples. The characterization results showed that the synthesis of graphitic carbon nitride, TiO2 nanoparticles and g-C3N4@TiO2 nanocomposites was successful. To investigate the photocatalytic properties of the synthesized samples, photocatalytic degradation tests of the colored pollutant methylene blue were used. The results of this test showed that the samples synthesized by the physical mixing method, which was introduced for the first time in this study, significantly improved the degradation of the pollutant methylene blue. So that the performance of the TiO2 / g-C3N4 (0.3) sample in the aqueous phase under UV and visible light irradiation has degraded 96.31 and 65.5 percent of MB dye within two hours, respectively, while the g-C3N4 sample has degraded 59.5 and 46 percent, respectively, under the same conditions, and the TiO2@g-C3N4 (0.3) sample has increased its performance by 36.81 percent under UV light and 19.5 percent under visible light. Also, three optimal nanocomposite samples with better optical performance have been selected and their performance in acrylic film has been investigated. To investigate the effect of the synthesized nanocomposites on the polymer film, the synthesized samples were used in an amount of two percent in the acrylic film and the photocatalytic properties of the degradation of methylene blue stain were investigated. AC-g-C3N4 film showed much better stain removal properties by removing MB stain with ∆b* under UV and visible light irradiation of 20 and 13, respectively, compared to AC-(0.3)TiO2@g-C3N4 film with ∆b* under UV and visible light irradiation of 14 and 5, respectively. It is concluded from this study that the photocatalytic properties of graphitic carbon nitride are enhanced by the formation of heterogeneous bonding structure with TiO2 nanoparticles and thermal exfoliation in the aqueous phase.
