Fast, economic and green synthesis of nitrogen-sulfur functionalized carbon quantum dots extracted from Ferula assa-foetida

Herein, a facile, nontoxic, economic and fast green synthesis method was utilized to prepare carbon quantum dotes (CQDs). The CQDs were prepared via microwave-assisted hydrothermal method using Ferula assa-foetida. plant as carbon source. The effects of microwave power and irradiation time on optical and photoluminescence properties of CQDs were investigated. The CQDs prepared under optimum power and irradiation time (100 W, 10 min) have the average diameter of ~ 6 nm and emitted a bright blue light, when they were excited under a UV light with λex = 360 nm. The florescent quantum yield (QY) of the CQDs was 33 % which is higher than other CQDs prepared by bio-source carbons. FTIR and SEM-EDS mapping results confirmed the presence of nitrogen and sulfur elements in the CQDs structure. The CQDs were implemented into polyvinyl alcohol (PVA) matrix to prepare PVA-CQDs films. The prepared films also emitted an intense bule light with CIE index of (0.185, 0.121). The green-synthesized CQDs and PVA-CQDs film via a fast, facile and economic approach, have great potential to be used in various application fields.