Synthesis of Ag-doped CuPc-ZnO/hydrophobic silica aerogel photocatalyst for enhanced photocatalytic degradation of floating benzene

Water pollution caused by water-immiscible pollutants such as BTXs (Benzene, Toluene, Xylene) has become a major concern for researchers in recent years. This study presents the synthesis of a hydrophobic photocatalyst, Ag-Copper Phthalocyanine (CuPc)-ZnO/Silica Aerogel, prepared using sol–gel and impregnation methods for the degradation of floating benzene. The effect of different percentages of Ag on the photocatalyst performance was studied, and the optimal sample was tested in rectangular and cylindrical photoreactors. The physicochemical properties of the hydrophobic photocatalyst were analyzed using XRD, FESEM, FTIR, BET/BJH, PL, contact angle, and UV-Vis DRS. Our analysis showed that decreasing nanoparticle size led to an increased specific surface area and decreased pore diameter. DRS analysis demonstrated that increasing Ag content led to a decreased bandgap and increased light absorption in the visible light region with CuPc addition. PL analysis indicated a significant decrease in electron-hole recombination with 5% Ag and confirms the efficient charge separation. The 5% wt. Ag sample achieved the highest benzene photodegradation efficiency, resulting in 95.27% degradation of benzene in 90 min. Additionally, the rectangular photoreactor surpassed in degradation rates, space-time yield (STY), photocatalytic space-time yield (PSTY), and quantum yield (QY) due to uniform light distribution and enhanced illumination compared to the cylindrical photoreactor. This study offers valuable insights on hydrophobic photocatalysts for degrading water-immiscible pollutants, emphasizing the need to optimize catalyst performance for efficient wastewater treatment.