Results 1 - 10 of 2012
Results 1 - 10 of 2012. Search took: 0.027 seconds
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[en] An efficient g-C3N4-based organic photocatalyst was synthesized by hybriding with a hole-transporting material, poly(3,4-ethylenedioxythiophene) poly(styrene sulfonate) (PEDOT:PSS). The PEDOT:PSS/g-C3N4 hybrid showed much enhanced photocatalytic activity for Rhodamine B degradation under simulated sunlight irradiation. When the hybridization amount of PEDOT:PSS was 0.25 wt%, the sample exhibited maximum photocatalytic activity, which was about 3 times as high as that of pure g-C3N4. Based on the photoelectrochemical and photoluminescence measurements, the possible charge transfer mechanism of enhanced photocatalytic activity was proposed.
[en] In the present paper Samsonov's major contribution in the science of refractory carbides has been centered on electronic structure, physical properties, mechanical properties including recrystallization, and sintering of refractory carbides. The consistent approach by Samsonov in applying his theory of stable electronic configuration model in studying the basic nature of carbides has also been discussed
[en] Highlights: • Bi2WO6 was in-situ successfully anchored onto g-C3N4. • The separation rate of the electron-hole pairs has been boosted. • Bi2WO6/g-C3N4 composites follow a direct Z-scheme mechanism. • The Bi2WO6/g-C3N4 composites display excellent activity and stability.
[en] Photometric observations of comets Bradfield 1987S and P/Borrelly were obtained with the ESO 1m-telescope. Absolute production rates of C2,C3 and CN as well as relative dust production rates were derived
[en] Is it possible to make artificial materials that match or exceed the ''hardness'' of the two hardest known materials diamond and cubic boron nitride? This question has long been of both basic and technological interest. Considerable excitement therefore greeted the recent theoretical prediction that the short, strong covalent bonds of a hypothetical crystal the ''hexagonal β form'' of carbon nitride (C3N4) would have a bulk modulus (and hence presumably a hardness) similar or greater than that of diamond. Unfortunately, numerous attempts to synthesize this form of carbon nitride have failed. Matching the hardness of diamond (80 00 GPa) or cubic boron nitride (50 GPa) is, it appears, no easy task. There may however, be a solution to this problem. In this article the authors explain how thin coatings can impart specific properties, such as high hardness, to a compound. They describe a method of obtaining high-hardness coatings in which a repeating layered structure of two materials with nanometre-scale dimensions (known as a superlattice) is deposited onto the surface. (UK)
[en] Graphitic carbon nitride (g-C3N4) has attracted considerable attention due to its special structure and properties, such as its good chemical and thermal stability under ambient conditions, low cost and non-toxicity, and facile synthesis. Recently, g-C3N4-based sensors have been demonstrated to be of high interests in the areas of sensing due to the unique optical, electronic and catalytic properties of g-C3N4. This review focuses on the most salient advances in luminescent sensors based on g-C3N4, chemiluminescence, cataluminescence and electrochemiluminescence methods are discussed. This review provides valuable information for researchers of related areas and thus may inspire the development of more practical and effective approaches for designing two-dimensional (2D) nanomaterial-assisted luminescent sensors.
[en] An electrochemiluminescence (ECL) based assay is described for the determination of the endocrine disruptor bisphenol A (BPA). The method is based on the use of carboxylated graphitic carbon nitride (C-g-C3N4) carrying an immobilized aptamer against BPA. In the presence of BPA, the ECL signal decreases due to ECL energy transfer from excited-state C-g-C3N4 to the BPA oxidation product. Under the optimal conditions, ECL intensity increases linearly in the 0.1 pM to 1 nM BPA concentration range. The detection limit is as low as 30 fM. The assay has excellent sensitivity, outstanding stability and high selectivity. It was applied to the determination of BPA in spiked water samples. .
[en] A novel g-C_3N_4/TiO_2 nanobelt (NB) heterostructure was successfully designed and prepared. The as-prepared g-C_3N_4/TiO_2 NB heterostructure exhibited high photocatalytic activity not only in the photodegradation of Rhodamine B (RhB) but also in photocatalytic H_2 production. The g-C_3N_4/TiO_2 NB heterostructure with a mass ratio of 1:1 demonstrated the best performance in the photodegradation of RhB, whereas a mass ratio of 3:1 demonstrated the highest H_2 production rate of 46.6 μmol h"−"1 in photocatalytic H_2 production. We conclude that the synergistic effect between g-C_3N_4 and TiO_2 NBs promotes the photogenerated carrier separation in space. This valuable insight into the rational architectural design of nanostructure-based photocatalysts is expected to shed light on other photocatalytic reaction systems in the future. - Graphical abstract: A novel strategy to fabricate the g-C_3N_4/TiO_2 nanobelt (NB) heterostructures was reported. The g-C_3N_4/TiO_2 NB heterostructures exhibited highly effective photocatalytic activities for photodegradation of Rhodamine B and H_2 production. - Highlights: • A novel strategy to fabricate the g-C_3N_4/TiO_2 NB heterostructures was reported. • The heterostructure exhibited high catalytic activity in photodegradation of RhB. • The heterostructure showed good H_2 productivity in photocatalytic water splitting. • The synergistic effect between g-C_3N_4 and TiO_2 NBs are important. • This study shows that the heterostructure can be an effective photocatalyst
[en] Highlights: • The successive heat-vacuum post-treatment induces bulk graphitic carbon nitride to a hollow microtube structure. • The successive heat-vacuum post-treatment also improves s-heptazine unit in graphitic carbon nitride. • The photocatalytic H2 yield of the modified graphitic carbon nitride is 10 times higher than that of common graphitic carbon nitride. This work provides a simple but efficient strategy for the adjustment of texture and regular morphology of graphitic carbon nitride (CN) material by the post-synthesis of successive heat-vacuum treatment (SHVT) method without using hard templates. The modified CN displayed various hollow microtubule structure and the improvement of s-heptazine unit depending on the SHVT temperature. The best hollow microtubule morphology with highest contents of the key s-heptazine structure can be achieved by SHVT at 540 °C. These modified CN samples led to the highest photocatalytic H2 yield of 1160 μL for 4 h reaction under visible light irradiation, which is almost 10 times higher than that of the traditional CN (118 μL). The results represent an alternative approach to preparing hollow microtubule morphology and improving the s-heptazine structure in CN for enhancing photocatalytic performance.