Biogenic nanocrystals (NCs) were synthesized from Ginkgo biloba leaf extract (GLE) and applied as photocatalytic and antibacterial agents. XRD patterns revealed the formation of ZnO/CuO NCs with a crystalline quality and intra-granular coupling, and HRTEM images showed the globular morphology indicating a porous nature. The lower PL intensity of ZnO/CuO NCs specified the slower recombination rate of electrons and holes for enhanced photocatalytic and antibacterial activity. The maximum photocatalytic degradation efficiency of methylene blue dye was 99% with ZnO/CuO NCs after 60 min under ultraviolet A (UV-A) light, which is much higher than the as-prepared (bare) NCs (75% for ZnO and 36% for CuO). For methylene orange (MO), the photocatalysis with ZnO/CuO NCs resulted in 83% removal efficiency in comparison to the bare ZnO and CuO (31% and 52%), respectively. The dye degradation with ZnO/CuO NCs followed pseudo-first-order kinetics and also exhibited excellent recycling stability even after five cycles. The antibacterial studies shows that gram-negative bacteria are efficiently killed by the NCs due to the surface interaction of the NCs and evolution of reactive oxygen species over the cell wall membranes. The photocatalytic active species correlated with the photodegradation mechanism of ZnO/CuO NCs and reactive oxygen species-based antibacterial activity. This study suggests that biogenic NCs can be used as a promising alternative photocatalyst for dye degradation in wastewater and also as a sustainable antibacterial agent.
|Number of pages||16|
|Journal||Journal of Materials Science: Materials in Electronics|
|Publication status||Published - Jul 2021|