Development of novel (BiO)2OHCl/BiOBr enriched with boron doped-carbon nanowalls for photocatalytic cytostatic drug degradation: Assessing photocatalytic process utilization in environmental condition

• Highly efficient nanocomposites were obtained solvothermally. • 5-fluorouracil was oxidized major by h + and minor by • O 2 - • The roles of B:DGNW in enhancing photocatalytic activity were complex. • Cytostatic drug was effectively photooxidized in actual fresh and sea waters. • (BiO) 2 OHCl/BiOBr-1.5%B:DGNW is a promising material for water purification. In this work, a series of novel (BiO) 2 OHCl/BiOBr-x%B:DGNW (x = 0%, 1%, 1.5%, 2%) composites with different content of boron-doped diamond/graphene nanowalls (B:DGNW) were fabricated by simple solvothermal synthesis. A boron-doped diamond/graphene nanowalls (B:DGNW) were prepared by CVD method. A series of analyses: XRD, XPS, SEM, and TEM showed that the photocatalyst (BiO) 2 OHCl/BiOBr-x%B:DGNW with a “flower-like” morphology was successfully synthesized. The photocatalytic activity of the obtained composites in the degradation of 5-fluorouracil (5-FU) in various water matrices (deionized water, sea, and surface water) under the influence of artificial solar radiation was assessed. The results showed that all the prepared (BiO) 2 OHCl/BiOBr-x%B:DGNW composites were characterized by excellent photocatalytic activity. The calculated pseudo-first rate constant for 5-FU degradation increased with the elevation of amount of B:DGNW up to 1.5% in (BiO) 2 OHCl/BiOBr, and it dropped down to value obtained for non-riched material by B:DGNW, when of 2% B:DGNW was introduced to composite. The results showed that B:DGNW play a key role in the separation of charge carriers h+/e- enhancing degradation rate of 5-FU. The photoactivity of (BiO) 2 OHCl/BiOBr-1.5%B:DGNW composite to 5-FU removal was also satisfied in natural water, although its structure has changed in seawater.