Investigating factors affecting the production of PVA/GO/BaTiO3 composite hydrogel and eva‎luating its photocatalytic properties

7/2/2024 12:00:00 AM

The removal of organic water pollutants by the photocatalytic method as a green method is one of the most important topics that has been on the agenda of many researchers since 2010. Improving and developing the properties of photocatalytic materials and increasing productivity, as a result, is one of the most important activities in this field. In this research, the photocatalytic properties of barium titanate and graphene oxide were used simultaneously. First, graphene oxide and barium titanate were synthesized by modified Hamers and hydrothermal methods, respectively. Then hydrogels of PVA and borax with different physical properties were synthesized and eva‎luated. To make these hydrogels, PVA powder, and distilled water were mixed for five hours at a temperature of 95 ℃ on a magnetic stirrer. After adding ethylenediamine to the PVA solution, the borax solution with different weight percentages of borax was added to this solution and the solution turned into a gel. In the next step, composites of barium titanate, graphene oxide, and PVA were made. In making these hydrogels, PVA solution and graphene oxide were mixed, and then a suspension of barium titanate powder in water was added to them. Borax solution was also added in the last step to form a gel. XRD, SEM, UV-Vis, and FTIR analyses were used to eva‎luate the synthesized material. The X-ray diffraction pattern of barium titanate powder confirmed the presence of an orthorhombic phase. The results of visible-ultraviolet spectroscopic analysis of composite hydrogels showed the absorption and degradation of methylene blue in xenon light. Dried hydrogels weighing 0.02 g in the presence of 200 cc of methylene blue aqueous solution with a concentration of 20 ppm for a period of 2 h were placed in a dark environment to reach the adsorption-desorption equilibrium. After that, the container containing the methylene blue solution and the sample were exposed to xenon light and samples were taken at specific time intervals. These samples were analyzed with a UV-Vis spectrometer. Three composite hydrogels with different percentages of graphene oxide and barium titanate were able to destroy more than 50% of methylene blue within 150 min. The best result belonged to the 50% wt barium titanate hydrogel, which was able to remove 88% of methylene blue. The presence of various carbon and oxide bonds was also confirmed by Fourier infrared spectroscopy.

فوتوكاتاليست , اكسيدگرافن , تيتانات باريم , كامپوزيت , پلي وينيل الكل

photocatalyst , graphene oxide , baruim titanate , composite , polyvinyl alcohol

zahra zahedi

Dr. hajar ghanbari