Abstract
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•BiVO4 was prepared and calcined at 400, 500, 600 and 700 °C.•Different wt.% of GO (5, 10, 15, 20 and 25) were loaded on BiVO4.•The addition of GO to the BiVO4 and calcination at 250 °C decreases the band gap energy till reaches 1.59 eV for the sample 10GBV4-250.•The calcination temperature, catalyst weight, initial dyes concentration and pH affect the photodegradation process.•MB and RhB molecules were completely removed after 30 and 50 min, respectively, over10GBV4-250 nanocomposite.•The prepared nanocomposites were more effective in destroying the three bacterial strains (E. coli, B. subtilis and C. Albicans).
Different BiVO4 (BV) and reduced graphene/BiVO4 nanocomposites photocatalysts were successfully prepared and used in the removal of MB and RhB dyes from aqueous solutions under indirect Sun light irradiation. The prepared samples were characterized by XRD, FTIR, SEM, EDS and TEM techniques. XRD, SEM and TEM analyses showed that the higher temperatures promote the particles growth and influence on the morphology and the structure of the BiVO4 powders that tightly attached to the graphene surface. FTIR and EDS analyses confirmed the reduction of GO into RGO by the calcination of GO/BiVO4 (GBV) nanocomposites at 250 °C. The band gap (Eg) results showed that increasing of the calcination temperature and graphene content were accompanied by a gradual decrease in the Eg till reaches 1.59 eV for 10GBV4-250 sample. The 10GBV4-250 nanocomposite was found to give the best results among the prepared photocatalysts; it removes MB molecules after 30 min and RhB molecules after 50 min. The kinetic studies showed that the photodegradation follows the pseudo-first-order kinetic behavior. The prepared photocatalysts exhibited good photocatalytic stability and reusability under indirect Sun light irradiation. The results of antibacterial activities showed that the nanocomposites are more effective in destroying three bacterial strains and the sample 10GBV4-250 gives the best results.