Facile oxidation reaction to produce monolayered highly crystalline nitrogen-doped graphene quantum dots

A new perspective on the photocatalytic action of titanium dioxide on phenol elucidated using comprehensive multiphase NMR

“…Approximately 20 mg of the photocatalyst, either commercially available Degussa P25 TiO 2 (Aerosil) or TiO 2 -NGQD composite, 23,24 was sonicated in 1 mL of D 2 O (Cambridge Isotopes, 99.9%). To this, 3 mL of a 61 mM 99% 13 C-labelled phenol (Cambridge Isotopes Lot#: PR-30613) in D 2 O was added to create the reaction solution, which was vigorously stirred for 30 min in the absence of light to establish an adsorption/desorption equilibrium of the phenol with the photocatalyst surface.…”

Engineering functionalization and properties of graphene quantum dots (GQDs) with controllable synthesis for energy and display applications

“…186 Various bottom-up synthesis methods have been proposed including synthesizing N-GQDs by irradiating microwaves with different power levels and durations on citric acid and urea, 187 as well as a post-synthesis oxidation step involving the treatment of H 2 O 2 to N-GQDs synthesized by hydrothermal reactions to enhance the overall crystallinity and purity of N-GQDs. 188 Furthermore, N-GQDs can be synthesized through a topdown approach by treating large carbon precursors like GO with N sources, leading to a higher doping level at the edge than on the basal plane of N-GQDs. Doping and edge states form a trap state in N-GQDs which absorbs charge carriers and contributes to improved storage capacity.…”

TiO2–NGQD composite photocatalysts with switchable photocurrent response

“…Based on the estimated sizes of TiO 2 (Fig. 2) and NGQDs, 30 there is an approximately equal number of TiO 2 and NGQD nanoparticles at 2% NGQD wt%. At this ratio, each TiO 2 nanoparticle is likely bound to 1 NGQD; at lower ratios, 'free' unbound TiO 2 is present and at higher NGQD wt%'s, we expect several NGQD particles to be bound to a single TiO 2 .…”

“…Heteroatom doping of graphene, notably with nitrogen due to its similar ionic radius, has been shown to enhance its absorbance in the visible region. Our group has recently reported on new advances in NGQD materials; specifically, by conducting a post synthesis oxidation we were able to increase the crystallinity, stability, and visible absorbance of the NGQDs, 30 which are all advantageous for photocatalytic material design.…”