g-C₃N₄ quantum dots: direct synthesis, upconversion properties and photocatalytic application

Abstract

Graphitic carbon nitride (g-C3N4) quantum dots (CNQDs) were prepared from bulk g-C3N4 directly by a thermal-chemical etching process. The CNQDs show strong blue emission as well as upconversion behavior, which can be used as universal energy-transfer components in visible-light-driven metal-free photocatalytic systems.

Reduced-sized monolayer carbon nitride nanosheets for highly improved photoresponse for cell imaging and photocatalysis

“…The time dependence of RhB photo-degradation reveals that almost 98% of the RhB aqueous solution was degraded over NMGCNs and GCNNs after 80 and 180 minutes, respectively. It is noted that, agreeing with previous report, the GCN quantum dots also show negligible photocatalytic activity under visible light, which is attributed to their ignorable photo-response under visible light [23]. The rate constants, quantitatively estimated by the kinetic principle of a pseudo first-order reaction are respectively 1.10 and 3.52 h −1 for the GCNNs and NMGCNs (Fig.…”

“…In addition, it has been demonstrated that reduced-sized GCNNs and GCN quantum dots with much smaller lateral dimension can be used for bio-imaging due to their distinct fluorescence with low photo-bleaching and low cytotoxicity [21]. However, multilayer GCNNs reported so far have a low fluorescence quantum yield (less than 20%) [8,9,22], and GCN quantum dots show ignorable photocatalytic activity under visible light irradiation [23]. It is believed that nanosized monolayer graphitic carbon nitride nanosheets (NMGCNs) would be highly photo-responsive for both photocatalysis and fluorescence.…”

Incorporating Graphitic Carbon Nitride (g‐C3N4) Quantum Dots into Bulk‐Heterojunction Polymer Solar Cells Leads to Efficiency Enhancement

“…In order to improve the dispersity of g-C 3 N 4 in o -dichlorobenzene, we then managed to prepare C 3 N 4 quantum dots (QDs) by using a modifi ed hydrothermal method reported in literatures. [ 26,27 ] The as-synthesized bulk g-C 3 N 4 was fi rst treated by H 2 SO 4 /HNO 3 mixed acids, [ 26,27 ] followed by a solvothermal treatment in o -dichlorobenzene at 200 °C for 10 h. As clearly illustrated in Figure 1 b, after such treatments the fl ake-like bulk g-C 3 N 4 turns into C 3 N 4 QDs, which have a size distribution of 10-20 nm with the average diameter of ≈16 nm. Interestingly, compared to the reported C 3 N 4 QDs prepared by hydrothermal treatment, [ 26,27 ] the average diameter of our C 3 N 4 QDs prepared by solvothermal treatment is much larger.…”

“…[ 4 ] However, rare studies were reported in applying g-C 3 N 4 in polymer solar cells (PSCs), which represent a promising renewable energy source featuring low-cost manufacturing, light-weight, high fl exibility, and easy roll-to-roll fabrication. [9][10][11][12][13] Recently, Xu et al reported the application of C 3 N 4 thin fi lms, prepared by a liquid-mediated -hybridization of carbon and nitrogen atoms, [1][2][3][4][5][25][26][27] an intriguing question is whether g-C 3 N 4 can play a similar role in BHJ-PSCs like graphene.…”

Fabrication of graphitic-C3N4 quantum dots coated silicon nanowire array as a photoelectrode for vigorous degradation of 4-chlorophenol

“…Compared with 2D g-C 3 N 4 , the strong quantum connement of g-C 3 N 4 QDs may arouse more effective optical absorption, and its small size will bring more active site expose effects. 20 Besides, QDs can achieve a coating for arbitrary shape of nanomaterials. Obviously, protecting SiNWs with g-C 3 N 4 QDs is a better choice than the reported protection materials.…”