Optical and Electrochemical Applications of Silicon–Carbon Dots/Silicon Dioxide Nanocomposites

Abstract

Various colors of photoluminescent SiC-dots/SiO2 prepared through a simple heating process have been employed for optical and electrochemical applications. Blue (B)-, green (G)-, and tan (T)-SiC-dots/SiO2 powders have been prepared from SiC-dots that had been prepared from 3-aminopropyl trimethoxysilane through a hydrothermal route by simply controlling heating at 60 °C for 60 min and 300 °C for 10 and 20 min, respectively. The B-, G-, and T-SiC-dots/SiO2 nanocomposites emit at 455, 534, and 574 nm, respectively, under excitation at 360 nm. B-, G-, and T-SiC-dots/SiO2 glass films show at least seven colors when excited at 360, 460, and 520 nm. Through a heat-induced photoluminescence (PL) change, a representative lithographic pattern of B-SiC-dots/SiO2 films has been fabricated using a near-infrared laser. The B-, G-, and T-SiC-dots/SiO2 also possess high electrocatalytic activity for the oxygen reduction reaction. Having such interesting PL and electrical properties, the stable, low-toxic, and cost-effective B-, G-, and T-SiC-dots/SiO2 nanocomposites show great economic potential in many applications such as light-emitting diodes, photoluminescent windows, and fuel cells.

Localization of Au Nanoclusters on Layered Double Hydroxides Nanosheets: Confinement‐Induced Emission Enhancement and Temperature‐Responsive Luminescence

“…Moreover, the QY was also investigated, with a value of 14.11% for the localized Au NCs on LDHs, which is largely improved compared with the value of 2.69% for pristine Au NCs in aqueous. The QY of 14.11% is at a high level compared with film materials based on quantum dots, carbon dots, or upconversion nanoparticles (normally 0.7%–15.7%), especially in the orange‐red emission region. Moreover, the incorporation of Au NCs into LDH nanosheets improves the QY from aqueous solution to solid films, rather different from the reduction of QY via traditional immobilization methods …”

Confined Synthesis of Carbon Nitride in a Layered Host Matrix with Unprecedented Solid‐State Quantum Yield and Stability

“…Herein, highly emissive ultrathin carbon nitride was synthesized within the 2D confined region of MgAl‐LDH via triggering the interlayer condensation of urea and citric acid (CA). The resulting carbon nitride intercalated in LDH (CN/LDH) emits strong cyan light upon UV light irradiation with a SSQY of 95.9 ± 2.2%, which is, to the best of our knowledge, the highest value of fluorescent carbon materials ever reported . Furthermore, the strong luminescence of CN/LDH is extremely inert to external stimulus including temperature and environmental pH, and its stability toward photobleaching is rather satisfactory.…”

Carbogenically coated silica nanoparticles and their forensic applications

“…Notably, nanopowders with high C-dot content Please do not adjust margins Please do not adjust margins are not photoactive, presumably due to extensive selfquenching effects 30 . A recent study suggests that blue, green and tan silicon-carbon dots/silica nanocomposite powders show adjustable optical properties as a function of their composition and structure 31 . Here we demonstrate colourtuneable nanopowders containing a single type of nanoparticles and are, thus, distinctly different from the nanocomposite and hybrid materials reported previously.…”