نوع مقاله : مقاله کامل پژوهشی
موضوعات
عنوان مقاله English
نویسندگان English
Graphene quantum dots are a class of carbon nanoparticles with tunable quantum properties, making them suitable for optical, non-electrical, biosensing, and energy applications, particularly in solar cells. In this study, these nanomaterials were functionalized using a simple, rapid, and convenient method with ammonium hydroxide as a nitrogen source. Nitrogen agents were added to graphene quantum dots at concentrations of 0, 2, 4, and 6 mol/L. To characterize the products, Raman spectroscopy, FTIR analysis, photoluminescence (PL), and UV–vis absorption measurements were performed. Surface morphology and interlayer spacing were examined using high-resolution transmission electron microscopy (HRTEM). FTIR results confirmed the presence of C–C and C–O bonds in the graphene quantum dots and indicated the formation of C–N and N–H bonds associated with nitrogen incorporation. Raman spectroscopy showed a relatively high ID/IG ratio in the functionalized samples, approximately 20% higher than in the pristine sample, reflecting the creation of structural defects. The increase in UV–vis absorption intensity also suggests the presence of nitride-like species on the surfaces of the graphene quantum dots. Photoluminescence studies in the excitation wavelength range of 320–420 nm revealed a strong emission peak around 500 nm, accompanied by enhanced fluorescence. These improved optical properties indicate that nitride-functionalized graphene quantum dots are promising nanoscale carriers for solar cells, optoelectronic devices, grating-sensor-based systems, and energy technologies, with the potential to enhance both efficiency and stability.
کلیدواژهها English