RSC Advances

Yang, Yan; Shi, YaWei

doi: 10.1039/c5ra12703cpmid: N/A

L-periaxin is an important scaffolding protein that is expressed in Schwann cells and lens fiber cells. In Schwann cells, loss or mutation of the PRX gene disrupts compact peripheral myelin and causes severe demyelination neuropathy. DRP2 is the only reported protein to interact with periaxin to form the L-periaxin–DRP2–dystroglycan (PDG) complex, which can provide structural and signaling functions by linking the extracellular matrix to the Schwann cell cytoskeleton. In this report, the interaction between L-periaxin and DRP2 was further investigated by bimolecular fluorescence complementation (BiFC), GST pull-down, CO-IP, and fluorescence spectroscopy. Results demonstrated that spectrin-like domain 2 of DRP2 played a critical role in the complex of DRP2 and L-periaxin. Furthermore, the DRP2 spectrin-like domain 2 only interacted with the NLS2 and NLS3 sub-domains in L-periaxin. These data revealed a previously unknown binding model between DRP2 and L-periaxin.

Moon, Sook Young

doi: 10.1039/c5ra17066dpmid: N/A

In this study, we present a method for controlling the waviness of carbon nanotube (CNT) arrays by adopting a two-phase catalytic system. In addition, we investigate the relationship between the catalyst state and the synthesis process of CNT arrays. As catalysts, we use two iron halides, iron(ii) chloride and iron(iii) chloride, combined in different ratios. The catalysts decompose and react with a silica surface on the substrate during the chemical vapor deposition process. The decomposed ions oxidize and precipitate over the substrate. An increased iron(iii) contribution decreases the waviness of CNT arrays. Furthermore, we demonstrate that the catalyst state affects the alignment, diameter, length, and waviness of CNTs.

Lin, Xue; Xu, Da; Lin, Zhe; Jiang, Shanshan; Chang, Limin

doi: 10.1039/c5ra17676jpmid: N/A

A novel triple-component TiO2/InVO4/RGO photocatalyst with dual channels for photogenerated charge separation has been successfully synthesized for the first time to improve photocatalytic activity under visible light. The synthesis involved loading of RGO particles on the surface of InVO4 microspheres to form RGO/InVO4, and then depositing TiO2 nanocrystals on the surface of InVO4 by hydrolysis of Ti(SO4)2 at low-temperature hydrothermal conditions. The TiO2/InVO4/RGO exhibited superior photocatalytic performance to bare InVO4, TiO2, TiO2/InVO4, RGO/TiO2, and RGO/InVO4 in degradation of Rhodamine B (Rh B) under visible light. It is suggested that the photogenerated electrons in the conduction band (CB) of InVO4 can quickly migrate to RGO, while the electrons also can be transferred to the CB of TiO2. The dual transfer channels at the interfaces of TiO2/InVO4/RGO result in effective charge separation, leading to enhanced photocatalytic activity. The concept of establishing dual channels for charge separation in a triple-component heterostructure provides a promising way to develop photocatalysts with high efficiency.

Lu, Zhansheng; Lv, Peng; Xue, Jie; Wang, Huanhuan; Wang, Yizhe; Huang, Yue; He, Chaozheng; Ma, Dongwei; Yang, Zongxian

doi: 10.1039/c5ra14057apmid: N/A

Single metal atom catalysts exhibit extraordinary activity in a large number of reactions, and some two-dimensional materials (such as graphene and h-BN) are found to be prominent supports to stabilize single metal atoms. The CO oxidation reaction on single Pd atoms supported by two-dimensional h-BN is investigated systematically by using dispersion-corrected density functional theory study. The great stability of the h-BN supported single Pd atoms is revealed, and the single Pd atom prefers to reside at boron vacancies. Three proposed mechanisms (Eley–Rideal, Langmuir–Hinshelwood, and a “new” termolecular Eley–Rideal) of the CO oxidation were investigated, and two of them (the traditional Langmuir–Hinshelwood mechanism and the new termolecular Eley–Rideal mechanism) are found to have rather small reaction barriers of 0.66 and 0.39 eV for their rate-limiting steps, respectively, which suggests that the CO oxidation could proceed at low temperature on single Pd atom doped h-BN. The current study will help to understand the various mechanisms of the CO oxidation and shed light on the design of CO oxidation catalysts, especially based on the concept of single metal atoms.

Zhu, Bai-Sheng; Jia, Yong; Jin, Zhen; Sun, Bai; Luo, Tao; Kong, Ling-Tao; Liu, Jin-Huai

doi: 10.1039/c5ra15619jpmid: N/A

Mesoporous 2-line ferrihydrite was synthesized through a facile precipitation method and was characterized by X-ray diffraction, transmission electron microscopy, and nitrogen adsorption–desorption isotherms. The surface area of the obtained mesoporous 2-line ferrihydrite was 331.0 m2 g−1. The fluoride adsorption performance was investigated. Batch adsorption experiments were conducted to study the influence of various factors such as contact time, initial fluoride concentration, temperature, pH value and co-existing anions on the adsorption of fluoride. The fluoride adsorption process fitted well with the Langmuir model, and the maximum adsorption capacity was 23.89 mg g−1 at pH 7.0. It is worth mentioning that this adsorbent performed well over a considerably wide pH range of 3–9. The fluoride adsorption kinetics over the adsorbent can be well described by a pseudo-second-order kinetic model. Thermodynamic parameters including the Gibbs free energy, standard enthalpy and standard entropy were calculated, and the results suggested that the adsorption of fluoride on the mesoporous 2-line ferrihydrite was thermodynamically favorable and exothermic in nature. Furthermore, Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy analyses revealed that the surface hydroxyl groups play an important part in the fluoride removal process.

Yang, Zhijun; Kuang, Wenyi; Weng, Peijin; Tang, Zhenghai; Guo, Baochun

doi: 10.1039/c5ra18098hpmid: N/A

Reduced graphene oxide (RGO) was prepared by the reduction of graphene oxide (GO) with rhodanine. During the reduction, rhodanine was converted into polyrhodanine via oxidative polymerization initiated by GO, and the RGO was subsequently decorated with polyrhodanine. The reduction process and polymerization have been verified. Rhodanine reduced GO with high efficiency. Additionally, rhodanine is polymerized during the GO reduction process. The wrapping of polyrhodanine onto RGO is also verified. Using this novel modification process, the elastomer/graphene composites were prepared by the in situ interfacial modification of elastomer/GO compounds with rhodanine during the processing. Because of the unique reactivity of polyrhodanine during curing, strong interfaces were observed to form in the resulting elastomer/RGO composites. Furthermore, because of the substantially improved interfacial adhesion, combined with the improved dispersion state, the elastomer/RGO composites exhibited significantly improved mechanical properties compared with the elastomer/GO composites. Regarding the facile process and strikingly high modification efficiency, the present work offers new insight into designing high-performance elastomer/graphene composites by combining interfacial chemistry and curing chemistry.

Sun, Mengxiao; Li, Tianhang; Zhang, Zhaoyuan; Wang, Nana; Xie, Aming; Lv, Xuliang; Wang, Yuan; Wu, Fan; Wang, Mingyang

doi: 10.1039/c5ra16389gpmid: N/A

Luffa sponge was used as a biotemplate for the growth of ZnO nanoparticles. This new structure of ZnO displayed a unique photocatalytic performance for dye degradation under visible light.

Shen, Hai-Min; Zhu, Gong-Yuan; Yu, Wu-Bin; Wu, Hong-Ke; Ji, Hong-Bing; Shi, Hong-Xin; Zheng, Yi-Fan; She, Yuan-Bin

doi: 10.1039/c5ra15592dpmid: N/A

Renewable β-cyclodextrin (β-CD) was immobilized onto the surface of hybrid silica using ethylenediamine as linking groups to construct an adsorbent in water treatment (CD@Si), and the obtained CD@Si was characterized through FT-IR, XPS, EDX, contact angle measurement, TGA, solid-state 13C NMR, SEM, and XRD analyses. The effect of initial pH, contact time on the adsorption performance of CD@Si for p-nitrophenol, and the adsorption kinetics, adsorption isotherms, adsorption thermodynamics, reusability and adsorption mechanism were investigated systematically, which indicate that the adsorption of p-nitrophenol onto CD@Si is a very fast process. The adsorption equilibrium can be reached in 15 s with an acceptable equilibrium adsorption capacity of 69.6 mg g−1 at pH 7.0, which is much faster than many reported adsorbents based on β-CD. The adsorption of p-nitrophenol onto CD@Si follows the pseudo-second-order model, obeys the Freundlich model, and is a feasible, spontaneous, and exothermic process which is more favorable at lower temperatures. And the formation of an inclusion complex and a hydrogen bond interaction are two origins of p-nitrophenol being adsorbed onto CD@Si. Additionally, CD@Si can be recycled and reused for at least five runs with an acceptable adsorption capacity, and is a very promising adsorbent for the fast adsorption of p-nitrophenol or its analogues from the aqueous phase. Additionally, this work also provides a strategy to increase the adsorption rate of adsorbents based on β-CD.

Chandrasekhar, P. S.; Komarala, Vamsi K.

doi: 10.1039/c5ra13799cpmid: N/A

We have investigated the role of graphene and Au@SiO2 core–shell nano-composite (NC), on the performance of dye-sensitized solar cells (DSSC) based on nitrogen doped TiO2 nanotubes (N-TNTs) as photoanodes. The N-TNTs were synthesized by an environmentally-friendly solvothermal method. The photoelectrochemical performance of DSSCs with N-TNTs improved compared to undoped TNTs; due to extended absorption in the visible part of the solar spectrum. An improved open circuit voltage was also observed with N-TNTs due to a change in the TiO2 Fermi energy level with increased electron density. After that, we investigated DSSC performance using graphene in N-TNTs with varying concentration from 0.2 to 1.0 wt%. With an optimal concentration of graphene (0.6 wt%), we have achieved 6.33% energy conversion efficiency, which is ∼47.5% enhancement in performance compared to pure N-TNTs. The enhanced device performance with graphene is mainly due to better dye loading, improved electron transport and charge collection process. To further boost the conversion efficiency of the DSSC based on graphene/N-TNTs NC, we introduced Au@SiO2 core–shell nanoparticles (NPs) of different concentration into the device structure. Finally, we are able to fabricate a DSSC having an energy conversion efficiency of 7.01% with 1.8% (w/w) of Au@SiO2 NPs, due to an improved excitation of dye molecules by generated strong near-fields around the Au NPs along with incident light far-fields.

Liu, Wei; Cai, Minhua; He, Yuegui; Wang, Shuai; Zheng, Jinwang; Xu, Xiaoping

doi: 10.1039/c5ra14867gpmid: N/A

A novel antibacterial polyacrylonitrile (PAN) membrane covalently immobilized with lysozyme was prepared. First, the virginal PAN membranes were prepared via the classic immersion precipitation method. After modification with NaOH, HCl, ethylenediamine (EDA), the lysozyme was covalently immobilized onto the surface of the PAN membranes by glutaraldehyde. The chemical compositions of virginal and modified membranes were characterized by Fourier transform infrared spectroscopy (FT-IR) and Energy Dispersion X-ray (EDX). The morphology and performance of the immobilized membranes were characterized by Scanning Electronic Microscopy (SEM), filtration performance measurements, the amount of bonded lysozyme, lysozyme activity measurement and flow cytometry method. The antibacterial tests confirmed that the immobilized lysozyme membrane displayed an excellent antibacterial performance against Staphylococcus aureus (S. aureus).