CdSe quantum dots capped with naturally occurring biobased oils

Abstract

We report a green synthesis of CdSe quantum dots (QDs) using bio-based materials (castor oil and ricinoleic acid) as capping agents. The absorption spectra of the as-synthesized CdSe QDs showed typical features of quantum confinement. The particle sizes of QDs were determined using the absorption band edges and found to be 3.81 to 6.80 nm and 5.91 to 8.31 nm for the entire range of reaction temperatures for QD-capped with castor oil (CSTO) and ricinoleic acid (RA), respectively. The photoluminescence spectra showed narrow emission peaks. The transmission electron microscopy (TEM) images showed spherical particles with sizes comparable to those determined from the absorption spectra. Comparatively, large particles were observed for RA capped CdSe QDs than those stabilized by CSTO. X-ray diffraction patterns revealed that the synthesized CdSe quantum dots have cubic structure. The particle sizes of CdSe deduced from X-ray diffraction measurements were in excellent agreement with those deduced from absorption spectra and TEM images. The d-spacings from the HRTEM images were consistent with those reported in literature. The surface area and the agglomeration number for as-synthesized CdSe QDs of different sizes are also reported.

Castor oil as a potential renewable resource for the production of functional materials

“…Green synthesis of chalcogenides nanomaterials using castor oil and its isolate ricinoleic acid as eco-friendly bio-based capping agents have recently been reported [73][74][75][76][77][78][79]. This is environmentally interesting because the use of castor oil and ricinoleic acid as both capping and dispersing agents, eliminate the need for the use of air-sensitive, toxic and expensive chemicals such as trioctylphosphine (TOP), trioctylphosphine oxide (TOPO) and alkyl amines.…”

“…It is worth noting that the boiling points of castor oil and ricinoleic acid are 586 and 685 K, respectively and thus they are simple to work with since they are liquid at room temperature. Literature reports the high ability of castor oil to prevent agglomeration of the synthesized nanoparticles due to the presence of long-chain hydrophobic moieties, thus forming ultra-small, well dispersed and stable quantum dots for a long period of time [76][77][78][79]. Some of these nanomaterials synthesized using castor oil or ricinoleic acid can be suitable for biological and medical applications because no toxic reagents are used in their preparation [80].…”

Synthesis of Amine Functionalized Mesoporous Silicas Templated by Castor Oil for Transesterification

“…Thus, various chemicals such as sebacic acid, undecylenic acid, 2octanol can be obtained from the castor oil [4]. Castor oil and ricinoleic acid have also been reported as a capping agent for nanoparticles synthesis [5,6] and have been used for biodiesel production via esterification and transesterification, respectively [7,8].…”

The use of castor oil and ricinoleic acid in lead chalcogenide nanocrystal synthesis

“…Castor oil and 12-hydroxyl-9-octadecenoic acid (ricinoleic acid) are both naturally occurring bio-based oils that are non-toxic and hence their use as solvents renders the synthetic route greener. There have been reports of the use of other green materials such as anacardic acid [4], olive oil [28], castor oil, and ricinoleic acid [29] for the synthesis of lead chalcogenides. In this study, lead chalcogenide materials were prepared using similar methods.…”