Enhancement of commercial dye photocatalytic degradation through the use of silver-doped kaolinite-zinc oxide quantum dots

To manufacture (Ag)Kao/ZnO-QDs, which are utilized to remove rhodamine B (RhB) and indigo carmine (IC) dyes, we present a simple pyrofabrication method for silver-doped kaolinite-zinc oxide quantum dots. A homogenous combination between zinc nitrate hexahydrate, silver nitrate besides kaolinite was completely mixed then heated gradually till 400 °C to create the very effective photocatalyst known as (Ag)Kao/ZnO-QDs. TEM, SEM-EDX, XRD, FTIR, XPS, ZP, UV-Vis DRS and BET were among the examination techniques used to analyze the (Ag)Kao/ZnO-QDs nanoparticle. To investigate the effectiveness of the (Ag)Kao/ZnO-QDs photocatalyst for elimination of IC and RhB dyes in aqueous solutions, various pH dye solutions were exposed to solar light during ambient conditions. A total pore volume of 0.0769 cc/g, an enhanced particular surface area of 50.3148 m²g^{- 1} and a pore size of 3.0565 nm were all characteristics of the generated nanostructure. Furthermore, 2.89 eV was found to be the optical band gap energy. Following 150 min of exposition to solar irradiation, the study indicates that the (Ag)Kao/ZnO-QDs nanostructure with optimal dose of 2000 and 2500 mg/L achieved the highest removal performance of IC and RhB dyes at 93.92 and 96.93%, respectively, at neutral conditions (pH = 7). The dye removal process of IC and RhB dyes followed first-order kinetics with rate constants of 0.0166 and 0.018 min^{- 1} at pH = 7, individually. Scavenger radical tests have demonstrated that superoxide radicals (^•O₂^-) are essential to the mechanism of the decomposition of IC dye. While superoxide radicals (^•O₂^-) plus hydroxyl radicals (^•OH) are necessary for the photocatalytic degradation pathway of RhB dye. After triple reuse studies, it was showed that the (Ag)Kao/ZnO-QDs nanoparticle was highly stable as evidenced by the photodegradation efficacy of IC and RhB dyes which went from 93.92 to 92.78, 91.54, and 89.76% as well as from 96.93 to 95.08, 94.11 and 92.58%, individually. The Box-Behnken design (BBD) which identified the optimal values for a number of variables was appropriate for the photocatalytic degradation tests.