Fabrication, Characterization and Response Surface Method (RSM) Optimization for Tetracycline Photodegration by Bi3.84W0.16O6.24- graphene oxide (BWO-GO)

RSM is a powerful tool for optimizing photocatalytic processes. The BWO-GO photocatalysts have been successfully synthesized via inorganic-salt-assisted hydrothermal method. XRD, TEM, FESEM, HRTEM and STEM are used to characterize BWO-GO heterojunction. UV-vis, PL, ESR and radical scavenger experiments are used to explore the photocatalysis mechanism. The photocatalysts are evaluated by TC photodegradation under visible light irradiation. And the main active species in TC photodegradation is ·O2-. Response surface methodology is used to optimize three key independent operating parameters, namely photocatalyst dosage (X1), percentages of GO (X2) and reaction time (X3), for TC photodegradation. The central composite design (CCD) is used to conduct experiments. The results showed that TC removal is significantly affected by the synergistic effect of linear term of X1 and X3. However, the quadratic terms of X12 and X32 had an antagonistic effect on T removal. The obtained RSM model (R2 = 0.9206) shows a satisfactory correlation between experimental and predicted values of TC removal. The optimized conditions is of 0.3 g photocatalyst dosage, 1.49 wt% GO loaded percentage and 90 min reaction time. Under this condition, theoretical prediction removal is 80.22% and the actual removal is 78.43%.