Developing novel photoactive bimetal Cr/Ag-codoped CeO2 nanozymes with synergistic activity toward biophotodegradation of organic dyes from real water media and textile wastewater

A novel biophotodegradation method of organic dyes was developed using photoactive bimetal Cr/Ag-codoped CeO 2 nanozymes with synergistic activity toward dye biophotodegradation from real water media and textile wastewater. The photoactive bimetal Cr/Ag-codoped CeO 2 nanozymes were synthesized and then comprehensively identified using several characterization methods. The developed bimetal Cr/Ag-codoped CeO 2 nanozymes revealed enhanced peroxidase-like activity. The introduced bimetal Cr/Ag-codoped CeO 2 nanozymes exhibited 6.66-order, 3.53-fold, and 2.0-order higher enzyme-like activity than the CeO 2, Ag-CeO 2, and Cr-CeO 2 , respectively, revealing the synergistic effect of bimetal-codoping on their catalytic activity. The photonanozymatic activity of the nanozymes was found to be 1.47-fold and 2.48-order higher than their nanozymatic and photocatalytic activity , respectively. Hence, they were applied for environmental mineralization applications via biophotodegradation of methylene blue . The effective factors on the yield of biodegradation were optimized by the one-factor-at-a-time method, providing maximal biophotodegradation of 99.95 % within 7.0 min. The storage and cycling stability of the developed photoactive bimetal Cr/Ag-codoped CeO 2 nanozymes were assessed, exhibiting that they are sable for at-least 30 days and 10 recycles without any change in their activity. The method was then practically applied for the treatment of water media (biophotodegradation, 98.7–99.6 %) and textile wastewater (biophotodegradation, 89.6–99.5 %). • A novel biophotodegradation method of organic dyes using photoactive bimetal Cr/Ag-codoped CeO 2 nanozymes. • Exhibiting 3.53-fold and 2.0-order higher enzyme-like activity than the Ag-CeO 2 and Cr-CeO 2 , respectively. • Providing 1.47-fold and 2.48-order higher photonanozymatic activity than nanozymatic and photocatalytic activity. • Exhibiting high storage and cycling stability for at-least 30 days and 10 recycles, in order • Practically application for the treatment of water media and textile wastewater.