Aggregation Mechanisms of Silica Particles in the Sol–Gel Synthesis of Promoted Silver Catalysts

Larichev, Yu. V.; Vodyankina, O. V.

doi:10.1134/s0023158419040062

Cited by 2 publications

(1 citation statement)

References 17 publications

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“… 45 However, as the reaction is continued longer in the absence of stabilizing surfactant, the already formed SiO 2 /CQD nanoparticles, which are richer in numbers and smaller in size, would undergo coalescence and then Ostwald ripening to form bigger particles, as observed from SEM images. Ostwald ripening is observed for SiO 2 particles under basic conditions, 46 when smaller particles having high surface energy (partially) redissolve in solution and deposit onto larger particles to enlarge particle size. In the absence of CQDs, homogeneous nucleation occurs after multiple condensations of hydrolyzed TEOS precursors.…”

Section: Resultsmentioning

confidence: 99%

Solid-State Phosphors from Coal-Derived Carbon Quantum Dots

et al. 2023

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With unique optical and chemical properties, carbon quantum dots (CQDs) find tremendous applications in chemistry, biology, and materials science to medicine. To expand the applicability of coal-derived CQDs from the liquid to solid state, we herein report the sustainable synthesis of solid phosphors from coal-derived CQDs using poly(vinyl alcohol) (PVA) and silica (SiO 2 ) as an organic and inorganic matrix. Two coal-derived CQDs were obtained using an eco-friendly ultrasonic-assisted wet oxidation method. The structural and chemical properties of the CQDs were extensively investigated and compared with commercial CQDs. The coal-derived CQDs exhibited blue fluorescence with 8.9 and 14.9% quantum yields. The CQDs were found to be self-co-doped with nitrogen and sulfur heteroatoms through surface and edge functional groups. Solid-state fluorescence of PVA/CQD composite films confirmed that the CQDs retained their excellent blue emission in a dry solid matrix. A facile one-pot sol−gel method was employed to fabricate SiO 2 /CQD phosphors with the unique fluorescence emission. Due to their special structural features, coal-derived CQDs favored the heterogeneous nucleation and rapid formation of SiO 2 /CQD phosphors. Further, coal-derived CQDs caused high-intensity white light emission with CIE coordinates of (0.312, 0.339) by endowing a suitable band gap structure in a SiO 2 / CQD solid phosphor for potential optical applications.

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Section: Resultsmentioning

confidence: 99%