Optimization of Silver Nano-Structure Growth Using Photo-Chemical Reduction

Tandra, Benedict Ethan Filbert (2025) Optimization of Silver Nano-Structure Growth Using Photo-Chemical Reduction. Other thesis, Institut Teknologi Sepuluh Nopember.

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Abstract

Studi ini memperkenalkan metode yang berkelanjutan, hemat biaya, dan terukur untuk mensintesis nanostruktur perak pada substrat berlapis emas untuk aplikasi Surface-Enhanced Raman Scattering (SERS). Dua metode fabrikasi berbantuan cahaya digunakan: iradiasi laser femtosecond (fs) pada kaca berlapis emas dan reduksi fotokimia berbasis LED menggunakan sumber LED 395 nm dan 448 nm pada wafer silikon berlapis emas. Perak nitrat dan asam askorbat berfungsi sebagai sumber perak dan agen pereduksi, dengan penambahan natrium sitrat dalam kasus-kasus tertentu untuk menyelidiki pengaruhnya terhadap morfologi.
Teknik laser fs memungkinkan kontrol yang tepat atas pembentukan dendrit, mengungkapkan bahwa peningkatan SERS yang optimal dicapai menggunakan 25 iterasi laser. Penambahan natrium sitrat dalam metode laser fs juga secara signifikan memengaruhi morfologi, mendorong terbentuknya struktur yang sangat bercabang menyerupai jarum. Metode berbasis LED menunjukkan bahwa paparan selama 25 menit pada 395 nm dan 448 nm menghasilkan dendrit yang sangat bercabang dan terdistribusi secara seragam dengan aktivitas SERS yang kuat. Sebaliknya, paparan LED yang lebih lama menghasilkan struktur yang terlalu besar dan efisiensi SERS yang berkurang, sementara penambahan natrium sitrat dalam sintesis berbasis LED menghasilkan struktur seperti lempengan dengan kinerja SERS yang menurun.
Nanostruktur yang dihasilkan dikarakterisasi menggunakan field emission scanning electron microscope (FE-SEM) dan dievaluasi kinerja SERS-nya menggunakan Rhodamine 6G dan laser 633 nm. Hasilnya mengonfirmasi pembentukan nanostruktur berkepadatan tinggi dengan aktivitas SERS yang kuat, menyoroti kemampuan penyesuaian morfologi dan peningkatan SERS melalui kondisi fabrikasi yang terkontrol dan penggunaan aditif dalam metode laser fs maupun berbasis LED.
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This study introduces a sustainable, cost-effective, and scalable method for synthesizing silver nanostructures on gold-coated substrates for surface-enhanced Raman scattering (SERS) applications. Two light-assisted fabrication methods were employed: femtosecond (fs) laser irradiation on gold-coated glass and LED-based photochemical reduction using 395 nm and 448 nm LED sources on gold-coated silicon wafers. Silver nitrate and ascorbic acid served as the silver source and reducing agent, respectively, with sodium citrate added in select cases to investigate its influence on morphology.
The fs laser technique enabled precise control over dendrite formation, revealing that optimal SERS enhancement was achieved using 25 laser iterations. The addition of sodium citrate in the fs laser method also significantly influenced morphology, promoting highly branched, needle-like structures. LED-based methods demonstrated that 25-minute exposures at both 395 nm and 448 nm yielded highly branched and uniformly distributed dendrites with strong SERS activity. In contrast, longer LED exposures resulted in overgrown structures and reduced SERS efficiency, while the addition of sodium citrate in LED-based synthesis led to plate-like structures with diminished SERS performance.
The resulting nanostructures were characterized using field emission scanning electron microscopy (FE-SEM) and evaluated for their SERS performance using Rhodamine 6G and a 633 nm laser. The results confirmed the formation of high-density nanostructures with strong SERS activity, highlighting the tunability of morphology and SERS enhancement through controlled fabrication conditions and additive use in both fs laser and LED-based methods.

Item Type:	Thesis (Other)
Uncontrolled Keywords:	surface-enhanced Raman scattering, iradiasi laser femtosecond (fs), reduksi fotokimia berbasis LED, pembentukan dendrit, struktur seperti lempengan, field emission scanning electron microscope surface-enhanced Raman scattering, femtosecond (fs) laser irradiation, LED-based photochemical reduction, dendrite formation, plate-like structures, field emission scanning electron microscope
Subjects:	T Technology > TA Engineering (General). Civil engineering (General) > TA1573 Detectors. Sensors T Technology > TA Engineering (General). Civil engineering (General) > TA441 Aggregates T Technology > TP Chemical technology > TP248 Nanogels. Nanoparticles.
Divisions:	Faculty of Industrial Technology and Systems Engineering (INDSYS) > Mechanical Engineering > 21201-(S1) Undergraduate Thesis
Depositing User:	Benedict Ethan Filbert Tandra
Date Deposited:	05 Aug 2025 01:38
Last Modified:	05 Aug 2025 01:38
URI:	http://repository.its.ac.id/id/eprint/127227

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