چكيده به لاتين
Photocatalysts have been considered one of the ways to solve the energy crisis and environmental pollution, due to their potential applications in the degrada-tion of organic pollutants, hydrogen production, and CO2 reduction. BiVO4 is known as a valuable photocatalyst that is sensitive to visible light. In this re-search, BiVO4 powders were synthesized using the combustion method and used as a photocatalyst to remove methylene blue (MB). In the synthesis of Bi-VO4, glycine was used as fuel in different amounts of fuel to oxidizer (ϕ) 0.5, 1, 2, and 3. The bismuth vanadate sample with a fuel-to-oxidant ratio of 1 had the highest photocatalytic degradation among the BiVO4 samples, which was equal to 90%. High specific surface area (8.738 m2. g-1), reduction of electron-hole recombination (through photoluminescence test), and large particle size (571-875 nm) of bismuth vanadate sample with ϕ=1 is the reason for the superior photocatalytic performance of this sample compared to the rest the effect of MB solution pH on the degradation of this substance was investigated (pH=11,1). Also, for the synthesis of BiVO4 / g-C3N4 composites by combustion method with different amounts of g-C3N4 (30, 15, and 40% by weight), precursors for the synthesis of bismuth vanadate with a ratio of fuel to oxidizer of 1 and graph-ite carbon nitride were used. Among BiVO4/g-C3N4 composites, the sample with 30% by weight of carbon graphite nitride showed the highest degradation, which was equal to 95%. Also, reduction of band gap, reduction of electron-hole recombination, and removal of bismuth oxide impurity were observed in the prepared composites compared to pure bismuth vanadate and pure g-C3N4 samples. Ensure the correct connection of bismuth vanadate particles with gra-phitic carbon nitride sheets, uniform distribution of bismuth vanadate particles on graphite carbon nitride sheets, and strong reduction of electron-hole recom-bination are the reasons for the excellent destruction of the composite sample with 30% of g-C3N4 compared to other samples. The effect of MB solution pH on the degradation of this substance was investigated (pH=10,2).
