Green synthesis of silver nanoparticles using mandarin orange (citrus reticulata) peel extract / Marian Angle S. Berenguer

UTHESIS (Bachelor of Science in Ceramic Engineering)

Bibliography : leaves 36-39

There are several methods for synthesizing silver nanoparticles (AgNPs),
including chemical reduction, microemulsion, sonochemical, sol-gel, and
electrochemical techniques. However, these chemical methods can be toxic and
expensive. In contrast, green synthesis using plant extracts, such as mandarin orange
peel (MOP) extract, offers a non-toxic, eco-friendly, and cost-effective alternative for
producing AgNPs. Thus, there is a need for "green synthesis" of nanoparticles, this
method avoids the use of high temperatures, pressures, energy, and toxic chemicals.
Silver nanoparticles are synthesized by the reduction of silver ions to neutral silver
atoms. This is achieved by the reduction of silver ions by a reducing agent. In this
study, silver nanoparticles (AgNPs) were synthesized through a green synthesis
method using the extracts from Mandarin Orange Peel (MOP) that acts as a reducing
agent. The effects of reaction time on the nanoparticles were investigated. Four (4)
treatments (reaction times) were conducted, each with three (3) replicates. Following
the reaction times, the samples underwent a centrifugation process to separate the
particles from the solution, and then it was characterized and analyzed utilizing XRF
and SEM technique. The pH level 4.9 adhered to the standard acidity criteria, and the
maximum absorption peak wavelength which is 390nm of the MOP extract was
within the acceptable range. The visible color change from light yellow to dark brown
indicated the rapid formation and nucleation of silver nanoparticles. The percentage
yield extracted from the solution obtained was low, having the highest yield of
11.80% only. Based on the XRF data analysis, (Ag) was not detected due to the
detection limits of the instrument. SEM revealed that the synthesized AgNPs
exhibited a structure consisting of spherical and cubical structures and average sizes
fall within the standard nanoparticles range of 1-100 nm. The smallest AgNPs,
averaging 33.59 nm in size, were synthesized through a 24-hour reaction.