Synthesis and characterization of visible light driven N-Fe-codoped TiO2/SiO2 for simultaneous photoremoval of Cr (VI) and azo dyes in a novel fixed bed continuous flow photoreactor

NFe-codoped TiO2/SiO2 nanocomposites were prepared and stabilized onto glass beads by coupling two methods of dip coating and heat attachment. The prepared nanocomposites were characterized by DRS-UV/vis, FTIR, XRD, FESEM, EDX, TEM, XPS, and N-2 adsorption/desorption analyses. The operational parameters of pH, flow rate, and the photoreactor's angle against sunlight were optimized to achieve the highest degradation efficiency. Then, the photocatalytic efficacy of the prepared substrates was examined in a novel fabricated photoreactor on a complex pollutant mixture consisting of Cr (VI), BR-29, BB-41, and BY-51, under two irradiation sources of visible light and sunlight. Moreover, to virtualize the process under natural irradiation conditions, the effectiveness of the performance was evaluated in various outdoor climate circumstances. Consequently, the results demonstrated the enhanced photocatalytic activity of the prepared nanocomposites under visible and solar irradiations. The removal percentages were also considerable under a partly cloudy sky and were 91.73%, 85.64%, 87.23%, and 58.59% for Cr (VI), BR-29, BB-41, and BY-51, respectively. The results showed the promising activity of the innovative photoreactor and the as-prepared nanocomposites for photocatalytic remediation of the water pollutants under natural climate conditions.