Two-Dimensional Self-Assembly of Boric Acid-Functionalized Graphene Quantum Dots: Tunable and Superior Optical Properties for Efficient Eco-Friendly Luminescent Solar Concentrators

Abstract

Carbon-based nanomaterials hold promise for eco-friendly alternatives to heavy-metal-containing quantum dots (QDs) in optoelectronic applications. Here, boric acid-functionalized graphene quantum dots (B-GQDs) were prepared using bottom-up molecular fusion based on nitrated pyrenes and boric acid. Such B-GQDs with crystalline graphitic structures and hydrogenbonding functionalities would be suitable model systems for unraveling the photoluminescence (PL) mechanism, while serving as versatile building blocks for supramolecular self-assembly. Unlike conventional GQDs with multiple emissive states, the B-GQDs exhibited excitation-wavelength-independent, vibroniccoupled excitonic emission. Interestingly, their PL spectra can be tuned without largely sacrificing the quantum yield (QY) due to two-dimensional self-assembly. In addition, such B-GQDs in a polystyrene matrix possessed an ultrahigh QY (∼90%) and large exciton binding energy (∼300 meV). Benefiting from broadband absorption, ultrahigh QY, and long-wavelength emission, efficient laminated luminescent solar concentrators (100 × 100 × 6.3 mm 3 ) were fabricated, yielding a high power conversion efficiency (1.4%).

Constructing Heterogeneous Photocatalysts Based on Carbon Nitride Nanosheets and Graphene Quantum Dots for Highly Efficient Photocatalytic Hydrogen Generation

“…Fortunately, graphene quantum dots (GQDs) as 0-dimensional nanomaterials have some special advantages, such as high dispersibility, a wide variety of active sites (edges, functional groups, dopants, etc. ), and better tunability of the chemical and physical properties [ 46 , 47 , 48 ]. Therefore, the GQDs have garnered considerable interest in the sectors of the conversion and storage of energy, electrical/optical/chemical catalysis, among others.…”

Fabrication of Orange Fluorescent Boron-Doped Graphene Quantum Dots for Al3+ Ion Detection

“…The fine spectrum of N1s has three peaks, which are N-B (398.08 eV), N-H (399.53 eV), and N-C (400.35 eV) [ 35 , 36 , 37 ]. The fine spectrum of O1s has four peaks, namely, C-O-C (530.22 eV), O-H (531.16 eV), C-O-O/C-OH (532.26 eV), and O-B (533.01 eV) [ 34 , 38 , 39 ]. The fine spectrum of B1s has four peaks, which are B-C (191.23 eV), B=O (192.3 eV), B2O3 (193.23 eV), and B-O (194.15 eV), respectively [ 35 , 40 , 41 ].…”

Synthesis, optical properties and applications of red/near-infrared carbon dots

“…13b) and a large exciton binding energy (∼300 meV), which can strongly resist to thermal quenching. 175 The as-fabricated laminated LSCs (10 × 10 × 0.63 cm 3 ) exhibited a clear concentrated light at its edges as shown in the inset of Fig. 13c.…”

“…Cai et al fabricated an LSC based on red emissive C-dots. 175 The C-dots were prepared using bottom-up molecular fusion based on nitrated pyrenes and boric acid. Due to the efficient surface functionalization, the as-prepared C-dots have an excitation-wavelength-independent emission ranging from 550 to 700 nm (Fig.…”

“…3c and d, yielding a PCE of ∼1.4%. 175 Summarizing, red/NIR C-dots may represent a viable solution to improve the functionality of LSCs.…”