Schematic Synthesis of Zinc Oxide Nanoflowers Decorated Flyash (ZnO@FA) Particles for Superior Photocatalytic and Antibacterial Applications

Flyash is a waste byproduct and a major environmental concern, whereas ZnO, owing to its many advantages such as stability, low cost, and wide band gap has been widely used in myriad applications. To address the environmental burden associated with the large‐scale generation of fly ash (FA), this study presents the development of a highly efficient and sustainable composite material. The FA core was chemically activated to impart a negative surface charge, while zinc oxide (ZnO) nuclei were functionalized with polyethyleneimine (PEI), enabling the formation of a ZnO@FA core–shell architecture decorated with uniformly distributed ZnO nanoflowers. The resulting composite was thoroughly characterized using techniques such as XRD, FESEM, HRTEM, FTIR, and BET analysis, and demonstrated outstanding performance as a photocatalyst for the degradation of fuchsin basic dye, along with strong antibacterial activity against E. coli and S. aureus . Compared to pristine FA, the enhanced performance is attributed to the optimized crystalline structure and increased surface area of the composite. Moreover, the material exhibits good reusability, highlighting its potential as a cost‐effective and sustainable solution for water purification and antimicrobial applications.