Carbon Quantum Dots: A Component of Efficient Visible Light Photocatalysts

Abstract

Carbon quantum dots (CQDs) have been developed as a new member of nanocarbons, characterized by the relatively easy preparation from a wide spectrum of carbonaceous precursors through either bottom-up or top-down routes. Attractive optoelectronic properties have been observed with CQDs, including efficient light absorption, variable photoluminescence (PL), unique up-conversion PL and prominent electron transport ability, which make CQDs an important component with great potential in the design of efficient visible light-driven photocatalysts. In this chapter, detailed contribution of CQDs to the enhanced visible light-driven photocatalysis will be included, in the classification of the role as electron mediator, photosensitizer, spectral converter and sole photocatalyst.

Removal of methyl orange (MO) using carbon quantum dots (CQDs) derived from watermelon rinds

“…The remarkable optical properties of CQDs are viewed as one of the essential factor that will influence the uses of CQDs. The Uv-Vis absorption spectrum of CQDs solution in the range of 300nm to 900 nm was exhibited in the Figure 3, which display only one intense absorption peak in the UV region at about 318 nm, which correlated to n-π* transitions of C=O bonds in CQDs with a tail elongate to the visible range and all the result are in agreement with the previously reported studies [8,39,40]. At the same time, since one of the beneficial roles of CQDs is extending the optical absorption range of photocatalyst, this optical characteristic lead to bandgap narrowing of the semiconductor when incorporate with CQDs owing to the chemical bonding that will be formed between the semiconductor and CQDs which in result can extend the light absorption range in enhancing photocatalytic degradation.…”

Carbon Quantum Dots for Biomedical Applications: Review and Analysis

“…The bandgap is created in a graphene sheet by forming sp 2 domains in such a way that conjugated π domains are isolated. The smaller the size of CQDs, the larger the bandgap emitting high energy (Cong and Zhao, 2018). They show strong absorption in the UV region but weak emissions.…”

A review on advancements in carbon quantum dots and their application in photovoltaics

“…Replacing oxygen functional groups on the CQDs surface with nitrogen-containing groups can readily transform CQDs into an n-type semiconductor. 70 …”