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Through the utilization of a facile procedure combined with anodization and hydrothermal synthesis, highly ordered alignment TiO2 nanotube arrays (TiO2-NTAs) were decorated with BiVO4 with distinctive crystallization phases of monoclinic scheelite (m-BiVO4) and tetragonal zircon (t-BiVO4), favorably constructing different molar ratios and concentrations of oxygen vacancies (Vo) for m&t-BiVO4/TiO2-NTAs heterostructured nanohybrids. Simultaneously, the m&t-BiVO4/TiO2-NTAs nanocomposites significantly promoted photoelectrochemical (PEC) activity, tested under UV–visible light irradiation, through photocurrent density testing and electrochemical impedance spectra, which were derived from the positive synergistic effect between nanohetero-interfaces and Vo defects induced energetic charge transfer (CT). In addition, a proposed self-consistent interfacial CT mechanism and a convincing quantitative dynamic process (i.e., rate constant of CT) for m&t-BiVO4/TiO2-NTAs nanoheterojunctions are supported by time-resolved photoluminescence and nanosecond time-resolved transient photoluminescence spectra, respectively. Based on the scheme, the m&t-BiVO4/TiO2-NTAs-10 nanohybrids exhibited a photodegradation rate of 97% toward degradation of methyl orange irradiated by UV–visible light, 1.14- and 1.04-fold that of m&t-BiVO4/TiO2-NTAs-5 and m&t-BiVO4/TiO2-NTAs-20, respectively. Furthermore, the m&t-BiVO4/TiO2-NTAs-10 nanohybrids showed excellent PEC biosensing performance with a detection limit of 2.6 μM and a sensitivity of 960 mA cm−2 M−1 for the detection of glutathione. Additionally, the gas-sensing performance of m&t-BiVO4/TiO2-NTAs-10 is distinctly superior to that of m&t-BiVO4/TiO2-NTAs-5 and m&t-BiVO4/TiO2-NTAs-20 in terms of sensitivity and response speed. [ABSTRACT FROM AUTHOR]

As the main component of syngas, reducing CO2 to CO with high selectivity through photocatalysis could provide a sustainable way to alleviate energy shortage issues. Developing a photocatalytic system with low cost and high performance that is environmentally friendly is the ultimate goal towards CO2 photoreduction. Herein, an efficient and economic three‐component heterojunction photocatalyst is designed and fabricated for converting CO2 to CO in the absence of organic sacrificial agents. The heterojunction is made of Cu2−xS nanotubes coated with a carbon layer (C‐Cu2−xS) and g‐C3N4. By using the classical MOF material HKUST‐1 as a precursor, hollow tubular‐like metal sulfides (C‐Cu2−xS) with carbon coating were synthesized and further loaded on g‐C3N4, forming a three‐component heterojunction C‐Cu2−xS@g‐C3N4. The carbon coat in C‐Cu2−xS@g‐C3N4 acts as an electron reservoir, which facilitates electron–hole pair separation. The optimized C‐Cu2−xS@g‐C3N4 acted as a photocatalyst in CO2 reduction with a high reactivity of 1062.6 μmol g−1 and selectivity of 97 %. Compared with bare g‐C3N4 (158.4 μmol g−1) and C‐Cu2−xS, the reactivity is nearly 7 and 23‐fold enhanced and this CO generation rate is higher than most of the reported Cu2S or g‐C3N4 composites under similar conditions. The prominent activity may result from enhanced light adsorption and effective charge separation. This work might open up an alternative method for the design and fabrication of high‐performance and low‐cost photocatalysts for efficiently and durably converting CO2 to CO with high selectivity. CO2 photoreduction: An efficient and economic three‐component heterojunction photocatalyst is designed and fabricated for converting CO2 to CO in the absence of organic sacrificial agents. The heterojunction is made of Cu2−xS nanotubes coated with a carbon layer (C‐Cu2−xS) and loaded onto g‐C3N4. [ABSTRACT FROM AUTHOR]

An anionic metal–organic framework (MOF) with 1D nanotube channels has been constructed. The charge and size dependent ion-exchange of cationic dyes was investigated. Rho@1 could be used as a dual-emitting fluorescent sensor for sensing explosives by self-referencing energy transfer behaviors. [ABSTRACT FROM AUTHOR]

The first polyoxometalate-based metal–organic nanotube constructed via covalent bonds has been synthesized. POM anions stick the metal–organic nanotubes to build 3D nanotubular arrays. The stability, magnetic and proton conducting properties are investigated. [ABSTRACT FROM AUTHOR]

A unique cationic metal–organic framework was synthesized by connecting the neutral rod-shaped secondary building unit with a cationic dicarboxylate ligand. This framework showed a rare snub square tessellation pattern by the periodic tiling of triangular and square nanotubes. The charge- and size-dependent ion-exchange of anion dyes was investigated. [ABSTRACT FROM AUTHOR]

Three molecules HArF@BNNT(5,0), HArF@BNNT(6,0), and HArF@BNNT(7,0) have been formed by HArF encapsulated in boron nitride nanotubes (BNNTs) with different sizes. Due to the interaction between the HArF and the BNNTs, the HAr bond lengths are in a decrease trend, while the ArF bond lengths are in an increase trend compared with those of HArF. To investigate the nature of the interaction between H and Ar and the interaction between Ar and F, the quantum theory of 'atoms in molecules' was carried out. The Laplacian (▿2 ρb) values of HAr suggest that the covalent interaction plays a key role in the H-Ar interaction. For ArF, the results indicate that the Ar-F interaction has a dominant noncovalent character. Moreover, the results obtained from the ratio of the kinetic-energy density ( Gb) and the potential-energy density ( Vb) (− Gb/ Vb) and the total energy density ( Hb) are in good agreement with that of ▿2 ρb values. In addition, the results of natural bond orbital charge and electron density difference between the HArF and BNNTs show that less electrons transfer away from the HArF to BNNTs with the gradual increase in the diameters of the BNNTs. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

The unusual properties of species with excess electrons have attracted a lot of interest in recent years due to their wide applications in many promising fields. In this work, we find that the excess electron could be effectively bound by the B atoms of boron nitride nanotube (BNNT), which is inverted pyramidally distributed from B-rich edge to N-rich edge. Further, Li@ B-BNNT and Li@ N-BNNT are designed by doping the Li atom to the two edges of BNNT, respectively. Because of the interaction between the Li atom and BNNT, the 2s valence electron of Li becomes a loosely bound excess electron. Interestingly, the distribution of the excess electron in Li@ N-BNNT is more diffuse and pyramidal from B-rich edge to N-rich edge, which is fascinating compared with Li@ B-BNNT. Correspondingly, the transition energy of Li@ N-BNNT is 0.99 eV, which is obviously smaller than 2.65 eV of Li@ B-BNNT. As a result, the first hyperpolarizability (3.40×104 a.u.) of Li@ N-BNNT is dramatically larger (25 times) than 1.35×103 a.u. of Li@ B-BNNT. Significantly, we find that the pyramidal distribution of the excess electron is the key factor to determine the first hyperpolarizability, which reveals useful information for scientists to develop new electro-optic applications of BNNTs. [ABSTRACT FROM AUTHOR]

Abstract: Three different nanotube structures, armchair, zigzag and wurtzite, were studied using B3LYP/6-31G(d) for carbon, BN, AlN and GaN nanotubes, respectively. Our calculations found that AlN and GaN can implausibly form the usual tubular morphologies of carbon and BN nanotubes. The same conclusion was confirmed based on analyzing the different configurations of benzene, borazine, and the analogies of the hexagonal Al3N3H6 and Ga3N3H6 at the same level of calculations. [Copyright &y& Elsevier]

A 3D chiral nanoporous coordination framework consisting of homochiral nanotubes assembled from octuple helices with a 19.4 Å by 22.4 Å aperture is formed by the parallel alignment of eight infinite helical chains. [ABSTRACT FROM AUTHOR]