| dc.description.abstract | In this study, the synthesis, characterization, and analysis of a ZnO/CuO composite
photocatalyst based on green tea leaf extract were successfully carried out. The
ZnO/CuO composite was synthesized using a green synthesis method. The synthesis
process began with the mixing of Zn and Cu precursor solutions with green tea leaf
extract, followed by stirring at 60 °C for 2 hours. After drying, the sample was calcined
at 500 °C for 4 hours to obtain a composite powder that was then characterized.
Characterization using SEM showed that the particle morphology was non-uniform
and exhibited agglomeration. This agglomeration is likely caused by van der Waals
forces between closely spaced particles. XRD analysis confirmed the formation of two
distinct crystalline phases, ZnO (hexagonal structure) and CuO (monoclinic
structure). The CuO peaks became more pronounced with increasing CuO content in
the samples. The addition of CuO also led to an increase in crystallite size and degree
of crystallinity. FTIR data showed absorption bands at 909 cm⁻¹ and 685 cm⁻¹,
indicating the presence of Zn–O and Cu–O bonds, as well as an –OH group around
3400 cm⁻¹ attributed to biomolecules from the green tea extract. UV-Vis analysis
showed that the maximum absorption wavelength of methylene blue was observed at
664 nm. The highest degradation efficiency was obtained in the ZnO:CuO = 8:2
sample, with a concentration reduction from 10 ppm to approximately 0.53 ppm, or
about 94.32%. This high photocatalytic activity is presumed to result from the
formation of a p–n heterojunction that enhances charge separation and boosts
photocatalytic performance. | en_US |
