Green synthesis of silver nanoparticles using madre cacao (gliricidia sepium jacq.) leaves aqueous extract/ Christian B. Dela Cruz, Shekinah P. Asencio, Yvonne Louise Kim F. Catama, and Shaira Joy T. Monreal.--

Bachelor's thesis

College Of Science.--
Bachelor of applied science in laboratory technology: Technological University of the Philippines,
2025.

Includes bibliographic references and index.

Several methods for synthesis of silver nanoparticles have been garnering attention,
specifically the use of biologically available materials that can act as the reducing agents
for the metal cations of silver like plant extracts. The present study demonstrated the use
of Gliricidia sepium aqueous plant extract for green synthesis and investigated the effects
of pH, volume ratio of reactants, silver nitrate concentration, temperature, and reaction time
on the physical properties of the silver nanoparticle. In this study, silver nanoparticles were
synthesized by the reduction method of silver nitrate using the aqueous extract of Gliricidia
sepium. The results showed that silver nanoparticles prepared using Gliricidia sepium
aqueous extract displayed a brownish yellow color, indicating the biosynthesis reduction
of silver nanoparticles. Additionally, the optimized conditions were found to be at pH 12,
a reactant volume ratio of 1:1.5 (plant extract to silver nitrate), using 5mM silver nitrate,
and under 70 - 80°C. The study concluded the successful synthesis of silver nanoparticles
that showed characteristics of 410 - 450 nm SPR peak, formation of Ag-O bonding at 600-
555 cm-1 in the FTIR spectra, a quasi-spherical shape of uniform clusters at 30 nm size,
and Bragg's reflection of (111), (200), and (220), further confirming the face centered cubic
(fcc) structure of the silver nanoparticles.