Synthesis and Characterization of Colloidal Quantum Dots

All materials were purchased from Sigma-Aldrich
unless otherwise stated. Lead(II) oxide (PbO, 99.999%), octadecene
(ODE, 90%), bis(trimethylsilyl) sulfide (TMS, synthesis grade), and
oleic acid (OA, extra pure, Thermo Fisher Scientific) were used for
the synthesis of lead sulfide colloidal quantum dots (PbS cQDs). Zinc
acetate (Zn(CH₃COO)₂, 99.99%), potassium hydroxide
(KOH, 99.99%), ethanol (CH₃CH₂OH, dry, max.
0.01% H₂O), methanol (CH₃OH, ≥99.8% puriss.
p.a.), and hexane (C₆H₁₄, 95% anhydrous) were
used for the synthesis of zinc oxide colloidal quantum dots (ZnO cQDs).
1,2-Ethanedithiol (EDT, 98%) and tetrabutylammonium bromide (TBABr,
99%) were used for ligand exchange. Lithium perchlorate (LiClO₄, 99.99%, dry), tetrabutylammonium perchlorate (TBAClO₄, 99%), ferrocenium hexafluorophosphate (98%), acetonitrile
(MeCN, 99.8% anhydrous), propylene carbonate (PC, 99.7%, anhydrous),
dimethylformamide (DMF, 99.8%, anhydrous), dimethyl sulfoxide (DMSO,
99.9%), anhydrous, tetrahydrofuran (THF, 99.9%, anhydrous), benzonitrile
(BN, 99%), N,N-diethylacetamide
(DEA, 97%), and acetone (99.8%, anhydrous, VWR) were used for the
electrochemical and spectroelectrochemical measurements. Indium tin
oxide on glass slides (0.7 mm thick, 7–10 Ohm/Sq) was purchased
from MSE Supplies and used as substrate for the cQD films.