Silver nanoparticles (AgNPs) are promising photocatalysts with a broad light absorption range and high catalytic activity. However, conventional synthesis methods often involve toxic chemicals, limiting their environmental applicability. In this study, we developed an eco-friendly bio-templating method to synthesize hierarchical micro/nano-structured silver (MNAg) photocatalysts that uses plant leaves, including Nelumbo nucifera (lotus leaf), Rosa sp. (rose petal), and Limonium sinuatum (statice petal), as natural templates. By modifying the leaf surfaces with citrate functional groups, AgNPs were selectively formed along the microstructures of the templates, preserving their hierarchical morphology. MNAg photocatalysts were subsequently obtained through controlled calcination, and successfully retained the microscale structure of the original template. The surface morphology, chemical composition and crystalline structure of the MNAg were characterized using scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD), confirming the successful formation of hierarchical AgNPs. The optical behavior of the MNAg, characterized with diffuse reflectance spectroscopy (DRS), demonstrated broadened absorption across the visible region, which is attributed to plasmonic coupling among the densely packed AgNPs, partially interconnected along the hierarchical surface. The photocatalytic performance of the MNAg materials was evaluated for methylene blue degradation under UV-Vis illumination. The MNAg derived from lotus leaves exhibited the highest photocatalytic efficiency. This study presents a sustainable route to hierarchical Ag photocatalysts, highlighting the potential of bio-inspired nanomaterials for environmental applications.

Abstract
1. 서 론
2. 실험 방법
    2.1. MNAg의 합성
    2.2. 광흡수 특성 및 광촉매 효과 분석
3. 결과 및 고찰
    3.1. MNAg의 합성
    3.2. 광흡수 특성 및 광촉매 효과 분석
4. 결 론
Acknowledgement
References
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• 박원우(대전과학고등학교) | Won Woo Park (Daejeon Science High School, Daejeon 34142, Republic of Korea)
• 황우찬(대전과학고등학교) | Woo Chan Hwang (Daejeon Science High School, Daejeon 34142, Republic of Korea)
• 인수현(대전과학고등학교) | Soo Hyun In (Daejeon Science High School, Daejeon 34142, Republic of Korea)
• 최한성(대전과학고등학교) | Han Sung Choi (Daejeon Science High School, Daejeon 34142, Republic of Korea)
• 김희준(대전과학고등학교) | Heejoon Kim (Daejeon Science High School, Daejeon 34142, Republic of Korea)
• 서성현(대전과학고등학교) | Seong-Hyeon Seo (Daejeon Science High School, Daejeon 34142, Republic of Korea)
• 윤정현(대전과학고등학교) | Jeonghyun Yun (Daejeon Science High School, Daejeon 34142, Republic of Korea)
• 한미영(대전과학고등학교) | Mi Young Han (Daejeon Science High School, Daejeon 34142, Republic of Korea) Corresponding author