Search

Deep eutectic solvents are utilized as green solvents to generate nanomaterials as they are less toxic and more cost-effective than conventional solvents. Contrary to a DES as a medium, metal-based DESs were employed as raw materials and media to fabricate one- or two-dimensional nanomaterials. FeO(OH) with a rod-bundle structure, Co(OH)2 with a plate-like structure, ZnO with a rod-like structure, and CuO with a wedge-like nanoplate have been successfully synthesized. A possible mechanism for formation is also discussed. Moreover, the nanomaterials obtained exhibit low band gaps compared to bulk materials, increasing their ability to degrade organic and inorganic pollutants effectively. According to electrochemical tests, Fe2O3 nanoparticles have a high specific capacity and cycle stability, making them promising anode materials for NiFe rechargeable batteries. [ABSTRACT FROM AUTHOR]

Cysteine‐functionalized Fe3O4 magnetic nanoparticles were synthesized by thiol‐ene click reaction and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier‐transform infrared spectroscopy (FT‐IR), X‐ray diffraction spectrometry (XRD), thermal gravimetric analysis (TGA), vibrating sample magnetometer (VSM), X‐ray photoelectron spectroscopy (XPS), specific surface area (BET) analysis and pore size distribution analysis. The obtained magnetic materials were employed as a magnetic solid phase extraction adsorbent combined with inductively coupled plasma‐atomic emission spectrometry (ICP‐AES) for determination of Cu2+. Several parameters affecting extraction efficiency, including eluent concentration, adsorption time, adsorbent amounts, and sample pH were investigated. Under the optimized conditions, the method was validated. Within the concentration range of 0.01–20 μg mL−1, The limit of detection (LOD) and the limit of quantification (LOQ) were determined to be 0.002 μg mL−1 and 0.007 μg mL−1, respectively. The adsorption percentage of Cu2+ ions remained above 87.0 % when the adsorption‐desorption data of Cu2+ ions through three cycles of the successive adsorption and desorption process. The results show that a reliable and rapid method was established for determination of Cu2+ ions. [ABSTRACT FROM AUTHOR]

A simple one-step hydrothermal route was designed to decorate NiCoS on the surface of carboxylated multiwalled carbon nanotubes (MWCNT-COOHs) to form coaxial MWCNT-COOH@NiCoS hybrid. When employed as supercapacitor electrode material, the MWCNT-COOH@NiCoS electrode shows a large specific capacitance and excellent rate performance. Coupled with activated carbon (AC) negative electrode, the operating voltage of MWCNT-COOH@NiCoS//AC asymmetric supercapacitor (ASC) could be extended to 1.5 V. Moreover, the MWCNT-COOH@NiCoS//AC ASC device achieves a maximum energy density of 33.6 Wh kg at a power density of 375 W kg with good cycle stability (about 83.3% of capacity was retained after 2000 cycles at 3 A g). In addition, a MWCNT-COOH@NiCoS//AC ASC device can drive a mini-fan. Therefore, the coaxial MWCNT-COOH@NiCoS hybrid is a promising supercapacitor electrode material. [ABSTRACT FROM AUTHOR]

Herein we prepare four novel D–π–A dyes based on triphenylamine (ZHG1, ZHG2, ZHG3 and ZHG4) by modifying the π-bridges. Compared with ZHG1, the power conversion efficiency (PCE) of ZHG2 is improved to 6.1% after the introduction of ethynyl. But further extension of the conjugation of the π-bridges by introducing the chromophore 4,8-bis(n-octyloxy)-benzo[1,2-b:4,5-b′]dithiophene (BDT) into ZHG3 conversely decreases the PCE to 4.6%. Improving the coplanarity by replacing cyclobenzene with thiophene in ZHG4 after introducing BDT further decreases the PCE of ZHG4 to 4.3%. Theoretical calculations indicate that the LUMOs of ZHG3 and ZHG4 were mainly delocalized over benzothiadiazole which is far from the anchoring groups. Cyclic voltammetry experiments indicate that the LUMO energy levels of ZHG3 and ZHG4 are lower than those of ZHG1 and ZHG2. Both of these results affect the ability to inject electrons into the TiO2 conduction band. X-ray photoelectron spectroscopy (XPS) analysis shows that the mean thickness of the dye coverage for ZHG1, ZHG2, ZHG3 and ZHG4 is 16 Å, 18 Å, 27 Å and 24 Å, respectively. So the tilt angle of the dye backbone anchored on the TiO2 film is in the order of ZHG1 ＞ ZHG2 ＞ ZHG4 ＞ ZHG3, which is consistent with the dye coverage of the outermost TiO2 surfaces. This result indicates that the intermolecular π–π aggregation in ZHG3 and ZHG4 with overlong π-bridges is more serious compared with that in ZHG1 and ZHG2. Perhaps the above two factors are the reason that the PCEs of ZHG3 and ZHG4 are lower than those of ZHG1 and ZHG2. So it is very important to find a balance point between the electron injection ability, intermolecular π–π aggregation and the expansion of the light absorption range. [ABSTRACT FROM AUTHOR]

Two new Y-shaped D–π–(A)2 type phenothiazine-based dyes (ZJA2 and ZJA3) were designed and synthesized for dye-sensitized solar cells (DSSCs). Compared to the single D–π–A analogue dye ZJA1, the Y-shaped dye with two carboxylic acid anchors was in favour of enhancing the performance of DSSCs. The FTIR spectra revealed that the dye ZJA2 molecules were anchored onto the TiO2 surface by two carboxylic acid anchors, which effectively increased the electron extraction channels. The steady-state emission spectra and time-resolved fluorescence experiments all indicated that the electron injection efficiency of dye ZJA2 was improved by the increased electron extraction channels, thus the Jsc of ZJA2 was greatly improved compared to dye ZJA1. In addition, benzene was used as the π-bridge for linking di-anchoring groups, combined with CDCA, thereby reducing the charge recombination. As a result, the PCE of the DSSC based on ZJA2 (4.55%) was 67% higher than the DSSC based on ZJA1 (2.72%). The Y-shaped D–π–(A)2 type phenothiazine-based dye ZJA3 containing two pyridine anchors was also investigated, and the DSSC based on ZJA3 showed a poor PCE (0.45%) due to the low dye loading. [ABSTRACT FROM AUTHOR]

Two new D–π–A zinc porphyrin dyes with thiophene and furan π-bridges have been synthesized and employed in dye-sensitized solar cells (DSSCs). Here, the triphenylamine (TPA) moiety was used as the electron donor, and the hexylthiophene chromophores were introduced onto the donor groups, which effectively extended the π-conjugation system. Although the two dyes had similar molecular structures, there was a significant difference between their optical and photoelectric properties. The EIS analysis suggested that the dye with the thiophene π-bridge had a lower charge recombination rate compared to the dye with the furan π-bridge. Based on their light-harvesting abilities, the power conversion efficiency (PCE) of dye JP-S was higher than that of dye JP-O. The JP-S-based DSSC showed a PCE of 5.84%, whereas the PCE of the JP-O-based DSSC was 4.68%. Moreover, using the dye TTR1 as a co-sensitizer made up for the poor absorption of porphyrin dyes in the 480–600 nm range and reduced the charge recombination. The JP-S + TTR1-based DSSCs showed a higher PCE of 6.71%, and the Jsc and Voc values of the device were both increased using this strategy. [ABSTRACT FROM AUTHOR]

Cysteine‐functionalized Fe3O4 magnetic nanoparticles were synthesized by thiol‐ene click reaction and characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier‐transform infrared spectroscopy (FT‐IR), X‐ray diffraction spectrometry (XRD), thermal gravimetric analysis (TGA), vibrating sample magnetometer (VSM), X‐ray photoelectron spectroscopy (XPS), specific surface area (BET) analysis and pore size distribution analysis. The obtained magnetic materials were employed as a magnetic solid phase extraction adsorbent combined with inductively coupled plasma‐atomic emission spectrometry (ICP‐AES) for determination of Cu2+. Several parameters affecting extraction efficiency, including eluent concentration, adsorption time, adsorbent amounts, and sample pH were investigated. Under the optimized conditions, the method was validated. Within the concentration range of 0.01–20 μg mL−1, The limit of detection (LOD) and the limit of quantification (LOQ) were determined to be 0.002 μg mL−1 and 0.007 μg mL−1, respectively. The adsorption percentage of Cu2+ ions remained above 87.0 % when the adsorption‐desorption data of Cu2+ ions through three cycles of the successive adsorption and desorption process. The results show that a reliable and rapid method was established for determination of Cu2+ ions. [ABSTRACT FROM AUTHOR]