دانلود رایگان مقاله لاتین نانوالیاف آلی ابرمولکولی از سایت الزویر
عنوان فارسی مقاله:
نانوالیاف آلی ابرمولکولی با عملکرد اکسیداسیون نوری نور مرئی بسیار کارآمد و پایدار
عنوان انگلیسی مقاله:
Supramolecular organic nanofibers with highly efficient and stable visible light photooxidation performance
سال انتشار : 2017
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مقدمه انگلیسی مقاله:
1. Introduction
The development of organic materials for water splitting under visible-light irradiation was regarded as one of the most promising scenarios for solar-energy utilization [1]. Over the past several years, the search for such materials has focused mainly on the metal-organic frameworks[2] and covalent organic polymers [3–6], such as polymeric carbon nitride [3], poly (diphenylbutadiyne) [4] and poly(azomethines) [6]. However, the present progress of research for these organocatalysts was far from the practical application owing to their intrinsic disadvantages of low sustainability, high cost, potential toxicity, complex synthetic route, poor structure tunability and limited photo-activity. Moreover, these organic photocatalysts were always employed to reduce water rather than act as a water oxidant. It is well known that the bottleneck reaction of water splitting was oxygen evolution due to the large overpotential and slow kinetics of four-electron charge-transfer process [7]. Therefore, the search for active organic photocatalysts that directly split water under visible light remains one of the most challenging tasks for solar-energy utilization.PDI (perylene-3,4,9,10-tetracarboxylic diimide) and its derivatives were regarded as one of the best n-type organic semiconductors and have been widely applied in phosphors [8], switches [9], sensors [10], organic field-effecttransistors (OFETs)[11,12] and solar cells [13,14] owing to its unique optical and electronic properties.15 The high thermal and photostability of PDI makes it an ideal candidate for water oxidation photocatalyst. Recently, the supramolecular architectures of PDI were employed as antennae chromophores working with the photocatalysts to construct water splitting system [16–19], such as PDI-Ni [16], PDI-Ru [17], PDI-TiO2 [18] and PDI-C3N4 [19]. However, in these composite systems, PDIs were introduced to act as dye-sensitizer rather than photocatalyst. Very recent, our group demonstrated that the purely unmodi- fied perylene diimide (PTCDI) supramolecular nonoassemblies can work as central catalyst to harness visible light to decompose organic pollutants as well as oxide water [20]. This result offers a new vista for the development of supramolecular organic materials in water splitting and waste-water cleaning. However, the photoactivities of such PTCDI nonoassemblies were still poor, especially for oxygen evolution (only 2.6 mol h−1 g−1). Moreover, limited by its intrinsic insolubility in organic solvents [15],the supramolecular self-assembly of PTCDI can be only performed in few special solvents such as concentrated sulfuric acid or m-cresol [21], which great restrict its structure tunability and photocatalytic performance.
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