Effect of Hybrid SiO₂ Shell on Electrochemical Properties of CdTe Quantum Dots Decorated Reduced Graphene Oxide (rGO).

On the basis of maintaining the original characteristics of each component, the composite material obtains the properties that the single component does not have through the synergy between the components. It is of great significance to understand the synergy between the components for the development of the composite. First of all, we prepared different emitting CdTe quantum dots (QDs), and then fabricated CdTe QDs@reduced graphene oxide (rGO) composites by a simple ultrasonic method. It is found that the fluorescence of QDs quenched, the photocurrent significantly improved, but the growth rate different from each other because of the different QDs. Afterwards, on the basis of naked QDs, hybrid SiO₂-coated QDs were fabricated by a two-step method. After that, hybrid SiO₂-coated CdTe QDs@rGO composites were prepared by the same method. It is found that the existence of the hybrid SiO₂ shell leads to the decrease of photocurrent of the composites before and after coating, but the specific capacitance significantly improved, and the cycle stability also better than the naked QDs. This research will make grapheme-based composites have broad application prospects in energy storage equipment.