Solution-processed organic–inorganic hybrids composing of MoO3 nanoparticles and PEDOT:PSS were developed for use in inverted organic solar cells as hole transporting layer (HTL). The hybrid MoO3:PEDOT:PSS inks were prepared by simply mixing PEDOT:PSS aqueous and MoO3 ethanol suspension together. A core–shell structure was proposed in the MoO3:PEDOT:PSS hybrid ink, where PEDOT chains act as the core and MoO3 nanoparticles connected with PSS chains act as the composite shell. The mixing with PEDOT:PSS suppressed the aggregation of MoO3 nanoparticles, which led to a smoother surface. In addition, since the hydrophilic PSS chains were passivated through preferentially connection with MoO3, the stronger adhesion between MoO3 nanoparticles and the photoactive layer improved the film forming ability of the MoO3:PEDOT:PSS hybrid ink. The MoO3:PEDOT:PSS hybrid HTL can therefore be feasibly deposited onto the hydrophobic photoactive polymer layer without any surface treatment. The use of the MoO3:PEDOT:PSS hybrid HTL resulted in the optimized P3HT:PC61BM- and PTB7:PC61BM-based inverted organic solar cells reaching highest power conversion efficiencies of 3.29% and 5.92%, respectively, which were comparable with that of the control devices using thermally evaporated MoO3 HTL (3.05% and 6.01%, respectively). Furthermore, less HTL thickness dependence of device performance was found for the hybrid HTL-based devices, which makes it more compatible with roll-to-roll printing process. In the end, influence of the blend ratio of MoO3 to PEDOT:PSS on photovoltaic performance and device stability was studied carefully, results indicated that the device performance would decrease with the increase of MoO3 blended ratio, whereas the long-term stability was improved.
Nanoscale zero-valent iron (nZVI) incorporated with nanomagnetic diatomite (DE) composite material was prepared for catalytic degradation of methylene blue (MB) in heterogeneous Fenton system. The material was constructed by two facile steps: Fe3O4 magnetic nanoparticles were supported on DE by chemical co-precipitation method, after which nZVI was incorporated into magnetic DE by liquid-phase chemical reduction strategy. The as-prepared catalyst was characterized by scanning electron microscopy, Fourier-transform infrared spectroscopy, X-ray diffraction, magnetic properties measurement and nitrogen adsorption–desorption isotherm measurement. The novel nZVI@Fe3O4-diatomite nanocomposites showed a distinct catalytic activity and a desirable effect for degradation of MB. MB could be completely decolorized within 8 min and the removal efficiency of total organic carbon could reach to 90% after reaction for 1 h.
Abstract The electrochemical behavior of uric acid (UA) and ascorbic acid (AA) on the surface of the cetyltrimethylammonium bromide (CTAB) incorporating chitosan film‐modified glassy carbon electrode (GCE) was investigated by linear sweep voltammetry (LSV) and differential pulse voltammetry (DPV). The modified electrode could completely separate the common merged voltammetric signals of UA and AA for 204 mV. Under the optimum conditions, the anodic peak currents of DPV were proportional to the concentration of AA in the range of 2.0 to 800.0 μM, and that of UA in the range of 0.5 to 200.0 μM. The proposed method was used to detect UA in urine with a satisfactory result.
Electrochemical behavior of nitrobenzene (NB) at a bismuth-film modified carbon paste electrode (BiF/CPE) in the presence of cetyltrimethylammonium bromide (CTAB) was investigated by square wave voltammetry. The electrochemical response of NB was apparently improved by CTAB due to the enhanced accumulation of NB at the electrode surface. Operational parameters including the deposition potential and time of bismuth film, pH of solutions and concentration of CTAB were investigated and optimized. Under optimized conditions, the cathodic peak current was proportional to the concentration of NB in the range of 1.0 × 10−6 to 1.0 × 10−4 mol L−1 with the detection limit of 8.3 × 10−7 mol L−1. The proposed BiF/CPE revealed good stability and reproducibility for rapid, simple and sensitive analysis of NB.
Abstract Cyclic alcohols (n = 5‐7) are compounds of distinctive nonplanar structure. Effect of the alcohols on micellization of sodium dodecyl sulfate (SDS) in aqueous solution are examined by determining the critical micelle concentration (CMC) by conductometry and the micelle aggregation numbers (N agg ) by fluorometry, respectively. In general, the CMC of SDS decreases with increase in volume of a cyclic alcohol in water and increases further after attaining a minimum value. The N agg of SDS varies little with small addition of a cyclic alcohol, but decreases when added in sufficient volume. Both the changes of the CMC and N agg with carbon number in the ring of the alcohols occur irregularly due to their steric reasons and nonplanar nature. The irregularity makes a difference between the cyclic alcohols and their chain counterparts. Based on 1 H NMR chemical shift measurements, the cyclic alcohols are found to be solubilized in the palisade layer in SDS micelles.
In this study, multi-walled carbon nanotubes (MWCNTs) and vitamin B12 (VB12) were fabricated on the surface of glassy carbon electrode (GCE). This modified electrode (MWCNTs/VB12/GCE) was designed to determine p-hydroxyacetophenone (p-HYD) by square wave voltammetry. The MWCNTs/VB12 film was characterized by Electrochemical impedance spectroscopy and Fourier transform infrared spectroscopy, which exhibited excellent electrocatalytic activity toward p-HYD by using square wave voltammetry. The peak current was linear with the concentration of p-HYD over the range of 0.5 - 250 µM with the detection limit of 0. 15 µM (S/N = 3). Furthermore, this proposed sensor has also demonstrated good reproducibility, high stability and excellent anti-interference ability. Keywords: Multi-walled carbon nanotubes, P-hydroxyacetophenone, square wave voltammetry, vitamin B12.
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