Analytical Methods
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2019
·Vol. 11
·期 7
·955-964
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IF 2.378
Lina Wang,Yong Li,Xike Tian,Chao Yang,Liqiang Lu,Zhaoxin Zhou,Yunjie Huang,Yulun Nie
Arsenic contamination in groundwater is a severe and major environmental problem that endangers public health. As such, a sensitive and selective methodology for the detection of this toxic metalloid must be urgently developed. Aldimine condensation reactions of p-phenylenediamine with salicylaldehyde derivatives yielded “turn-on” fluorescence probes (HBHP, HBBP and HMBP) for the detection of As(V) with high sensitivity. Among these, as a typical AIEgen, HBHP exhibits the highest detection sensitivity. The detection limit of HBHP for As(V) was calculated to be 0.88 ppb, which is due to its higher ability to form intermolecular hydrogen bonds to convert twisted intramolecular charge transfer (TICT) into planar intramolecular charge transfer (PICT) and its higher molecular planarity triggered by specific electronic effects. Job's plots and DFT theoretical studies indicate that HBHP binds to As(V) with a stoichiometry of 1 : 2, and the binding constant was determined using the Benesi–Hildebrand equation to be 4.26 × 104 M2. Commonly existing anions and cations in groundwater exhibited no interference with the selective detection of As(V). Spiking and recovery tests of HBHP in the presence of As(V) in actual water samples gave satisfactory experimental results. Our research would provide novel principles of molecular construction and materials for the detection of As(V) in groundwater.
研究领域:
环境科学
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分析化学
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DOI
高影响因子
Journal of Materials Chemistry C
·
2014
·Vol. 2
·期 28
·5709-5716
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IF 0
Hongzhang Liu,Rongcheng Bo,Haifeng Liu,Najun Li,Qingfeng Xu,Hua Li,Jianmei Lu,Lihua Wang
In this paper, two conjugated small molecules (CZ-BT and TPA-BT) were designed and successfully synthesized to investigate the influence of different electron donor moieties on thin-film morphology and their electrical memory device properties. Current–voltage (I–V) curves indicated that both CZ-BT and TPA-BT exhibited stable dynamic random access memory (DRAM) characteristics under appropriate Al evaporation rate condition, but with different threshold voltages, the former lower than the latter due to its better film morphology and closer intermolecular stacking. Furthermore, the performances of the two devices under different Al electrode evaporation rates was also investigated, and the results showed that the CZ-BT-based device still exhibited original DRAM characteristics, whereas the TPA-BT-based device exhibited WORM characteristic when Al electrode evaporation rate was increased to 5 Å s−1. The variation of storage characteristics of TPA-BT could be mainly attributed to its poor film-forming property, and the Al nano-particles would penetrate into the film during the quick evaporation process to form filamentary conduction leading to WORM behavior.
研究领域:
材料科学
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电子工程
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DOI
CHEMICAL ENGINEERING JOURNAL
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2022
·
IF 16.744
Qungui Wang,Keli Wang,Cheng Yan,Xiankan Zeng,Xuehai Fu,Jingjing Cao,Shiyu Yang,Wen Li,Xiangrong Chen,Weiqing Yang
Effectively balancing carrier injection of perovskite LEDs (PeLEDs) for next-generation display and illumination urgently needs for molecularly understanding carrier injection behavior of electron transport layer (ETL)/perovskite toward further developing high performance PeLEDs. Here, we molecularly reveal the electron injection behaviors of PeLEDs by theoretically-experimentally decoupling the electron transport of ETLs and electron injection of TmPyPB/perovskite and TPBi/perovskite. Resulted, the better molecular planarity bridging effect (MPBE) of TmPyPB than TPBi can effectively increase electronic-coupling for the improved electron transport ability and significantly decrease injection barrier for the enhanced electron injection capability, intrinsically leading to a more balanced carrier injection and a less electron accumulation of PeLEDs. Compared to TPBi-based PeLEDs, the TmPyPB-based PeLEDs present the obviously-increased average EQE, current efficiency, power efficiency and luminance by 44 %, 63 %, 43 % and 100 %, respectively. Meanwhile, this PeLED shows a higher voltage tolerance characteristic of 7.5 V than that of TPBi-based PeLEDs (6.25 V). Therefore, this work may provide a fundamental insight into carrier injection behavior of PeLEDs for effectively-regulating its carrier injection balance and further for its greatly-facilitated commercialization.
研究领域:
材料科学
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光学工程
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DOI
高影响因子
SOLAR ENERGY
·
2019
·
IF 4.674
Xinkai Song,Xichuan Yang,Haoxin Wang,Jincheng An,Ze Yu,Xiuna Wang,Anders Hagfeldt,Licheng Sun
Two push–pull metal-free sensitizers with 5,11-dihydroindolo[3,2- b ]carbazole derivatives as electron-donating groups and 4-(benzo[ c ][1,2,5]thiadiazol-4-ylethynyl)benzoic acid (BTZ) as electron-withdrawing unit, denoted by SK201 and SK202, were synthesized and used for fabrication of dye-sensitized solar cells (DSSCs). SK202 contains a thienyl group between the donor and acceptor, whereas in SK201 the donor and acceptor are connected directly by a single bond. Introduction of a thienyl group improved the planarity of the dye molecule, broadened the absorption spectrum , enhanced the molar extinction coefficient, increased the dye loading on TiO 2 , and accelerated interface electron transfer on TiO 2 . This fine tuning of dye structure improved the performances of DSSCs based on SK202 sensitizers and gave a power conversion efficiency (PCE) of 11.0% ( J sc 16.5 mA cm −2 , V oc 932 mV, and fill factor 71.7%), compared with that of 7.2% for SK201 , under standard AM1.5G solar irradiation (100 mW cm −2 ) with a Co(II/III) complex based redox couple.
研究领域:
材料科学
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能源技术
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DOI
高影响因子
Journal of Physical Chemistry C
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2022
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IF 4.177
Junyi Feng,Rong Hu,Jianjun Jiang,Zekai Cai,Shusheng Pan,Xianshao Zou,Geng Dong,Ningjiu Zhao,Wei Zhang
In this work, we report the aggregation-induced emission in a polymeric donor material poly(bis(2-butyloctyl)[2,2′:5′,2″-terthiophene]-4,4″-dicarboxylate-5,5′-diyl-vinylene) (PTVT-T), which exhibits a high device performance for the application of photovoltaics. Time-dependent density functional theory calculations and steady-state and time-resolved spectroscopy have been employed to reveal the underlying emission mechanism. We find that the aggregation of the PTVT-T polymer chain in solution increases the exciton luminescence lifetime and exciton emission quantum yield, which is related to the effective torsional inhibition of carbon–carbon single bonds. Compared with the aggregates in solution, the exciton emission quantum yield of the aggregates in PTVT-T film is reduced. It is attributable to exciton delocalization caused by the improvement of molecular planarity in film. We also observe that the as-cast film and thermally annealed film show distinctly different emission behaviors. This work can shed light on designing optoelectronic polymer materials with the integration of photovoltaic and light-emitting functions.
研究领域:
材料科学
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光子学
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有机电子学
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物理化学
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产品关联
DOI
高影响因子
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