TY - JOUR T1 - Effect of pH on Optical Properties of Graphene Oxide Quantum Dots TT - JF - ijop JO - ijop VL - 14 IS - 2 UR - http://ijop.ir/article-1-411-en.html Y1 - 2020 SP - 135 EP - 142 KW - Graphene Oxide KW - Quantum Dots KW - pH KW - Photoluminescence KW - UV-Vis. N2 - Luminescent graphene oxide quantum dots (GOQDs) have attracted tremendous attention from scientists in chemistry, materials, biology, and physics science. They have specific properties such as low cytotoxicity, excellent electrochemical and optical properties, resistance to photo-bleaching, and good stability. In this study, GOQDs were synthesized using a simple and straightforward methodology. The synthesized GOQDs were characterized by Fourier Transform Infrared (FTIR) analyzer, ultraviolet–visible spectrophotometry (UV–VIS) absorption, Photoluminescence (PL) spectroscopy, and transmission electron microscopy (TEM) analyses. Then, optical properties of GOQDs such as absorption and luminescence with various pH values were investigated. GOQDs show absorption in the ultraviolet (UV) region and their position of photoluminescence peak is independent of pH value. The average size of QDs is less than 5 nm, as revealed by TEM. The GOQDs show green luminescence under UV irradiation (360 nm). M3 10.52547/ijop.14.2.135 ER -