Preparation of a polyaniline-supported Ce-Ag-doped ZnO nanocomposite for efficient photocatalytic degradation of acid blue 113 dye
Mortaza Elahian, Najmeh Ahmadi, Amir Abbas Heidari, Nezamaddin Mengelīzadeh, Davoud Balarak
Abstract
• Ce-Ag-ZnO/PANI was prepared and used as a photocatalytic for acid blue 113 removal. • BOD 5 /COD ratio increased from 0.21 to 0.72 and BOD 5 /TOC increased from 0.61 to 1.27. • Mineralization, energy consumption, radical scavenger, and toxicity tests were conducted. • Ce-Ag-ZnO/PANI acts as an efficacious catalyst and is recyclable. • 100 % Acid blue 113 degradation efficiency was achieved under optimum conditions. In this research, ZnO nanocomposite doped with cerium and silver/polyaniline (Ce-Ag-ZnO/PANI) was synthesized as a photocatalyst for eliminating Acid Blue 113 (AB113) dye. XRD, FESEM, EDX, TEM, UV–Vis, and FTIR analyses were employed to investigate the synthesized samples. Photocatalytic tests demonstrated the better efficiency of synthesized nanocomposite compared to other samples (ZnO and Ce-Ag-ZnO). The result presented that after 60 min of testing, 100 % of AB113 dye was destroyed by this nanocomposite. Energy consumption during the process was calculated to be between 21.3 and 37.8 kWh/m³, depending on radiation intensity ranging from 8 to 32 W. The mineralization level was determined by the percentage of Total Organic Carbon (TOC) removal, while the degree of biodegradability was estimated based on the BOD₅/COD (biological oxygen demand over 5 days/chemical oxygen demand) and BOD₅/TOC ratios. The TOC removal percentage was 0.81 %. Also, the BOD 5 /COD ratio increased from 0.21 to 0.72, and BOD 5 /TOC increased from 0.61 to 1.27. Scavenging experiments showed that ● OH and O 2 •– and holes, all three factors contributed to the degradation of AB113, although the main role was played by the • OH. The findings ascertained that the degradation kinetics follows the pseudo-first-order kinetic (PFO) model. The reaction rate constant for AB113 degradation with Ce-Ag-ZnO/PANI was equal to 0.096 min −1 , which was 8.13 and 11.4 times higher than the dye degradation with ZnO and Ce-Ag-ZnO catalysts. Due to its efficient and stable photocatalytic activity, the Ce-Ag-ZnO/PANI synthesized in our study was considered an operative photocatalyst in degrading organic pollutants individually or simultaneously.