Decoration of carboxylated multi-wall carbon nanotubes with quantum dots

Purification of multi-wall carbon nanotubes (MWCNTs) from the iron catalyst and amorphous carbon and associated with that process, their oxidation with conc. HNO3 over 100 °C on sonication to carboxylated MWCNTs (CMWCNTs) is presented. A novel way of decoration of CMWCNTs with ZnO and ZnS quantum dots (QDs) is proposed. It involves the use of corresponding ammonium zincates. CNT–COO–Zn–X where X = OH and SH, respectively, provided nucleation for the QDs growth. That approach does not require any non-covalent mediation from either inorganic or organic carriers.