December 6, 2025
Dariush Saberi

Dariush Saberi

Academic Rank: Associate professor
Address:
Degree: Ph.D in Chemistry
Phone: 07731222424
Faculty: Faculty of Nano and Biotechnology

Research

Title
Green synthesis and characterization of new photocatalyst, silver and bromine modified cadmium sulfide nanoparticles, and evaluation of their practical application toward fenton-like photo-biodegradation of organic dyes from water media
Type Thesis
Keywords
سنتز شيميايي، نانوذرات كادميم سولفيد، نقره، برم، فتوكاتاليست، تخريب زيستي
Researchers pardis ahmadi (Student) , Dariush Saberi (First primary advisor)

Abstract

Background: Photocatalysts, especially nanophotocatalysts, are materials that speed up chemical reactions by absorbing light (either visible or ultraviolet) and facilitating electron transfer between reactants. However, many conventional photocatalysts have limitations, such as only being effective under UV light and suffering from rapid charge recombination, which reduces their efficiency. From an environmental perspective, the reliance on UV light makes them less sustainable, and from an economic standpoint, the need for artificial light sources increases costs. Aim: Researchers are working to develop new materials that perform well as photocatalysts under visible light, aiming to create solutions that can function using natural sunlight instead of UV sources. In this study, novel silver and bromine modified cadmium sulfide nanoparticles were designed, synthesized, and evaluated for its potential to efficiently degrade methylene blue dye in water. The nanocrystals demonstrated strong photocatalytic activity and excellent reusability. Methodology: The synthesis of the silver and bromine modifiedcadmium sulfide nanoparticleswas carried out using a simple, one-step, eco-friendly method. Various characterization techniques, including scanning electron microscopy (SEM), transmission electron microscopy (TEM), fluorescence spectroscopy, UV-visible spectrophotometry, and X-ray diffraction (XRD), were used to analyze the properties of the nanocrystals. Their photocatalytic performance was then tested for degrading methylene blue in water. Key factors such as reaction time, catalyst dosage, pH level, light source, initial dye concentration, and ionic strength were examined to determine optimal conditions. Conclusions: Under optimized conditions, the nanoparticlessuccessfully degraded 99% of methylene blue within 60 minutes. Their stability was also evaluated, showing that after 30 days, they retained about 75.8% of their initial efficiency. Kinetic studies revealed that th