Journal of Materials Chemistry A
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2020
·Vol. 9
·期 1
·413-422
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IF 11.301
Xiaohuan Chang,Junjie Fu,Dongxing Kou,Wenhui Zhou,Zhengji Zhou,Shengjie Yuan,Yafang Qi,Zhi Zheng,Sixin Wu
The introduction of alkali metal (AM) post-deposition treatment (PDT) has led to the consecutive breakthrough of world record efficiencies for Cu(In,Ga)Se2 photovoltaics. However, for the derivative Cu2SnZn(S,Se)4 (CZTSSe) solar cells, the corresponding verdict seems partially unjustified due to the difference in defect chemical environment and phase structure, and the most effective incorporation means of AMs is still a mystery. In this work, for the first time, we developed a dual AM synergistic incorporation strategy combining light and heavy AMs by post-depositing CsF after NaF-PDT to improve the efficiency of CZTSSe solar cells. The relevant microscopic-electrical advantages with regard to the different roles of NaF and CsF PDT are discussed in more detail. It was found that the Na atoms are randomly dispersed both in the grain interior (GI) and grain boundaries (GBs), significantly increasing the acceptor concentration and passivating the deep level defects to enhance the Voc. In contrast, the Cs atoms are mainly segregated at the GBs, primarily increasing the potential of the GBs and improving the FF. The prominent electric benefits of Cs at the GBs and Na in the GI finally increase the device efficiency from 10.12% to 12.16%. Our findings solve the difficulty in obtaining the available Voc and FF for future high efficiency research and should serve as a basis for the in-depth understanding of AM-PDT in kesterite photovoltaics.
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ADVANCED FUNCTIONAL MATERIALS
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2020
·Vol. 31
·期 8
·2008033
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IF 16.836
Ying Liu,Yue Jiang,Zhe Hu,Jian Peng,Weihong Lai,Dianlun Wu,Shouwei Zuo,Jing Zhang,Bin Chen,Ziwen Dai,Yingguo Yang,Yang Huang,Wei Zhang,Wei Zhao,Wang Zhang,Lei Wang,Shulei Chou
Vanadium-based materials are fascinating potential cathodes for high energy density Zn-ion batteries (ZIBs), due to their high capacity arising from multi-electron redox chemistry. Most vanadium-based materials suffer from poor rate capability, however, owing to their low conductivity and large dimension. Here, we propose the application of V 2 C MXene (V 2 CT x ), a conductive 2D nanomaterial, for achieving high energy density ZIBs with superior rate capability. Through an initial charging activation, the valence of surface vanadium in V 2 CT x cathode is raised significantly from V 2+ /V 3+ to V 4+ /V 5+ , forming a nanoscale vanadium oxide (VO x ) coating that effectively undergoes multi-electron reactions, whereas the inner V-C-V 2D multi-layers of V 2 CT x are intentionally preserved, providing abundant nanochannels with intrinsic high conductivity. Owing to the synergistic effects between the outer high-valence VO x and inner conductive V-C-V, the activated V 2 CT x presents an ultrahigh rate performance, reaching 358 mAh g −1 at 30 A g −1 , together with remarkable energy and power density (318 Wh kg −1 /22.5 kW kg −1 ). The structural advantages of activated V 2 CT x are maintained after 2000 cycles, offering excellent stability with nearly 100% Coulombic efficiency. This work provides key insights into the design of high-performance cathode materials for advanced ZIBs.
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APPLIED SURFACE SCIENCE
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2020
·
IF 6.182
Lanlan Gan,Qian Su,Zhangbao Chen,Xiaoming Yang
Detections of carcinogen and vitamins are generally recognized to be meaningful, especially for nitrites (NO 2 − ) and ascorbic acid (AA). Here blue-fluorescence carbon dots (CDs) with the quantum yield of 11.83% were successfully synthesized by using folic acid and nicotinic acid, and their surfaces were identified to be abundant in the functional groups of amide, carboxyl and hydroxyl. Importantly, the amide on the surfaces of CDs showed the interactions with the nitrites and formed the complex, thus resulting in their quenched fluorescence. To be specific, the fluorescence intensity of CDs proportionally decreased by adding the increased amounts of NO 2 − from 8 to 800 μM, and achieved the detection of NO 2 − at a detection limit of 21.2 µM. Moreover, further introducing ascorbic acid could prevent CDs with NO 2 − to form the complex and recover their fluorescence, and thus providing the new avenue of assaying AA with the generally favorable linear range of 0.1–800 μM, while its related detection limit was 50 µM. In addition, the synthesized CDs exhibited the satisfactory sensitivity toward different pH values, demonstrating their potential of sensing pH. Consequently, the proposed CDs here may provide a new way of monitoring NO 2 − and AA in the target samples.
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ChemElectroChem
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2020
·Vol. 7
·期 9
·2136-2144
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IF 4.154
Xixue Zhang,Yanhua Wan,Kaiwei Yang,Keming Song,Liwei Mi,Guoqiang Zheng,Xiangming Feng,Weihua Chen
Graphical Through the layers : Cotton cloth-induced flexible hierarchical carbon film is facilely obtained with distinctive carbon nature, unique porous microstructure and crosslinked-network, as flexible substrate for sodium-ion batteries (SIBs). It exhibits favorable flexibility, fast kinetics, and high structural and electrochemical stability, due to predominant surface-controlled reaction mechanism, effective surface chemistry and favorable compatibility with electrolytes. Flexible substrates play a decisive effect on the functions of flexible energy storage devices. However, systematical investigation and understanding of often-used flexible carbon-based substrates is lack. In this work, a reliable cotton cloth induced flexible hierarchical carbon film is facilely obtained. The synthesized-carbonized cotton cloth (SCC) owns distinctive carbon nature with perfect order level and defects, unique porous microstructure, and crosslinked-network. The SCC exhibits favorable flexibility, fast kinetics, high structural and electrochemical durability with high performance (239.4 mAh g −1 and 155.2 mAh g −1 at 0.01 A g −1 in the ether- and ester-based electrolyte in sodium-ion batteries, respectively), superior to commonly-used commercial carbon cloth and graphene film. In addition, the predominant surface-controlled reaction mechanism, effective solid electrolyte interphase and favorable compatible features with different electrolytes are also intensively studied.
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Polymers
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2020
·Vol. 12
·期 3
·551
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IF 3.426
Jie Zhao,Xiangqiang Pan,Jian Zhu,Xiulin Zhu
Stimuli-responsive functional gels have shown significant potential for application in biosensing and drug release systems. In this study, aggregation-induced emission luminogen (AIEgen)-functionalized, diselenide-crosslinked polymer gels were synthesized via free radical copolymerization. A series of polymer gels with different crosslink densities or tetraphenylethylene (TPE) contents were synthesized. The diselenide crosslinker in the gels could be fragmented in the presence of H2O2or dithiothreitol (DTT) due to its redox-responsive property. Thus, the TPE-containing polymer chains were released into the aqueous solution. As a result, the aqueous solution exhibited enhanced fluorescence emission due to the strong hydrophobicity of TPE. The degradation of polymer gels and fluorescence enhancement in an aqueous solution under different H2O2or DTT concentrations were studied. Furthermore, the polymer gels could be used as drug carriers, suggesting a visual drug release process under the action of external redox agents. The AIEgen-functionalized, diselenide-crosslinked polymer gels hold great potential in the biomedical area for biosensing and controlled drug delivery.Keywords:polymer gels;redox response;aggregation-induced emission (AIE);fluorescent probes;drug release carriers
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PubMed
高影响因子
ADVANCED SYNTHESIS & CATALYSIS
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2020
·Vol. 362
·期 12
·2337-2341
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IF 5.851
Wei Hang,Yaping Yi,Chanjuan Xi
Cobalt-catalyzed reductive carboxylation of aryl bromides with carbon dioxide has been developed. The reaction proceeded under one atm pressure of CO 2 at 40 °C in the presence of cobalt iodide/2,2′-bipyridine catalysts and zinc dust as a reducing reagent. Various aryl bromides could be converted to the corresponding carboxylic acids in good to high yields. Preliminary mechanistic experiments ruled out intervention of intermediate organozinc species for carboxylation with CO 2 , thus suggesting a direct CO 2 insertion into the corresponding ArCoBr species.
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CHEMICAL ENGINEERING JOURNAL
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2020
·
IF 10.652
Xiangming Fang,Guanhong Lu,Asad Mahmood,Yan Wang,Xiao Wang,Xiaofeng Xie,Zhihong Tang,Jing Sun
The photocatalytic application of TiO 2 is limited due to low light harvesting abilities in the whole solar spectrum and fast recombination of the photoinduced electron-hole pairs. Herein, we report a TiO 2 -based ternary composite photocatalyst (MT@rGO-x; x = 0.05–0.2) with a pearlescent color effect, which incorporates a mica reflection core and a rGO multifunctional shell as cocatalysts. The micro flake composites were synthesized by a facile precipitation route and applied first to photodegrade gaseous acetaldehyde. MT@rGO-0.1 composite has optimal performance, which is 2.5 times photodegradation efficiency and 3 times CO 2 mineralization efficiency higher than those of pure TiO 2 . The enhanced photocatalytic performance of MT@rGO composite is associated with effectively improved light harvesting of TiO 2 by mica reflection. The presence of rGO facilitates the separation of electron-hole pairs and pollutant absorption. In addition, the superoxide radical was proved as the decisive active species for the photodegradation of acetaldehyde by electron spin resonance analyses and radical quenching tests. Our MT@rGO photocatalyst is expected to be applied as a functional and decorative additive of car paint, which is subject to photodegradation due to air pollutants.
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GREEN CHEMISTRY
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2020
·Vol. 22
·期 11
·3597-3607
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IF 9.48
Hai-Qin Xiao,Wen-Hui Zhou,Dong-Xing Kou,Zheng-Ji Zhou,Yue-Na Meng,Ya-Fang Qi,Sheng-Jie Yuan,Qing-Wen Tian,Si-Xin Wu
Cu2ZnSn(S,Se)4 (CZTSSe) solar cells have been receiving considerable attention in recent years, owing to their low cost and toxicity as well as a high abundance of their constituent elements. Solution-based (mainly precursor solution) methods have been widely used in the fabrication of CZTSSe-based thin film solar cells. Though most record solar cells since 2009 have been achieved using solution-based methods, carbonaceous residues are always formed during post deposition treatment (PDT). These carbonaceous residues are detrimental to grain growth of CZTSSe to form large grains. The presence of unwanted small grain layers will increase the series resistance and reduce the fill factor of the solar cell, thus consequently decreasing the efficiency of CZTSSe solar cells. Herein, we propose “green” supercritical carbon dioxide (SCCO2) treatment to overcome the challenge of carbonaceous residues. FT-IR, SEM, XRD and Raman characterization studies were used to confirm the reduction of carbonaceous residues in CZTSSe films. The solar cell fabricated from a selenized CZTSSe precursor film with SCCO2 treatment under optimal conditions showed the best conversion efficiency of 11.23% (VOC = 0.456 V, JSC = 36.6 mA cm−2, FF = 67.1%). To the best of our knowledge, this is the first report on boosting the efficiency of solution-based CZTSSe solar cells by using SCCO2 treatment. In addition, this unique SCCO2 treatment may also bring forth new ideas for other solution-based optoelectronic devices.
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CHEMICAL ENGINEERING JOURNAL
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2020
·
IF 10.652
Ziqiu Ren,Na Wang,Peicheng Wei,Minghuan Cui,Xin Li,Chaochao Qin
As a classical electron transport layer, the high crystallinity TiO 2 has been widely used in perovskite solar cells (PSCs), however, its high-temperature preparation process elevates the fabrication cost and limits its application. Here, we report an ultraviolet-ozone assisted strategy to modify low-temperature TiO 2 interface for PSCs. In addition to the more appropriate work function and reinforced built-in potential, the lattice strain of perovskite films crystallized on modified TiO 2 has also been released in some degree. Ultrafast transient absorption technique is employed to provide a deep insight into the carrier dynamics, revealing that less non-radiative recombination exists in the modified device. Interestingly, transient surface photovoltage results demonstrate that ultraviolet-ozone modification can efficiently suppress the decomposition of perovskite films under light illumination. Taking advantage of these facts, this device exhibits better efficiency and remarkable stability. This demonstrated low-temperature strategy is a promising way for fabricating low-cost, efficient and stable perovskite device.
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ANALYST
·
2020
·Vol. 145
·期 10
·3528-3534
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IF 3.978
Zhijian Mai,Hao Li,Yixun Gao,Yue Niu,Yongrui Li,Nicolaas Frans de Rooij,Ahmad Umar,M. S. Al-Assiri,Yao Wang,Guofu Zhou
A tetraphenylethylene (TPE) derivative (N,N-dimethyl-N′-(4-(1,2,2-triphenylvinyl)phenyl)acetimidamide, TPE-amidine) was designed and synthesized, and used to prepare visible CO2 chemosensors, TPE-amidine-L (liquid) and TPE-amidine-S (solid). The hydrophilicity of TPE-amidine thoroughly changed because of the unique reversible reaction between the amidine group and CO2, which controlled the molecular aggregation extent in water by CO2. Combining with the well-known aggregate-induced emission effect, the highly selective CO2 chemosensor TPE-amidine-L was developed, which has the lowest CO2 detection limit of 24.6 ppm compared with other reported CO2 chemosensors, and can be regenerated within 10 s by adding triethylamine. With the aim of being safer and more convenient to use, a polyacrylamide hydrogel containing TPE-amidine was prepared as a renewable CO2 sensing “tape” (TPE-amidine-S). The flexibility, adhesivity, CO2 sensitivity and reversibility of the “tape” is systematically investigated, showing great potential for “on-site” and “real-time” CO2 detection in practical applications.
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PubMed
高影响因子
IONICS
·
2020
·Vol. 26
·期 7
·3307-3314
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IF 2.394
Zhu Yuhao,Han Yu,Wang Hui,Guo Qingpeng,Jiang Huize,Sun Weiwei,Xie Wei,Zheng Chunman,Xie Kai
Due to its high capacity and low density, lithium metal is considered as one of the most promising anodes for next-generation lithium batteries. However, the problems of dendrite and volume change are the main obstacles to limit its further development. Therefore, it is of great significance to realize the stable plating and stripping of lithium metal. The stability of lithium metal can be improved by compositing lithium with conductor materials, but the effect of conductor materials on lithium composite anode needs to be further studied. Herein, ionic or electronic conductor powders are introduced into the interior of lithium metal by hot-melt mixed coating method; Li/Cu, Li/Zn, and Li/Li 3 N composite anodes are prepared; and their electrochemical performances in solid and liquid batteries are studied. The results show that plating and stripping of lithium in composite anodes will take place preferentially around electronic or ionic conductor, rather than around lithium itself. For liquid batteries, the introduction of electronic conductor in lithium composite anode will make the electric field distribution more uniform and thus make the lithium deposition more stable, while the introduction of ionic conductor in composite anodes can improve the electrochemical stability of composite anodes in solid-state batteries. The capacity of the Li/Cu-LFP battery was 42.5 mAh g −1 after 500 cycles at 10 °C, corresponding to the 77% retention of its initial capacity.
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APPLIED CATALYSIS B-ENVIRONMENTAL
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2020
·
IF 16.683
Pan Li,Gan Luo,Shuang Zhu,Lingju Guo,Peng Qu,Tao He
Catalytic reduction of CO 2 is usually accompanied by competitive H 2 evolution. However, the selectivity between CO 2 reduction and H 2 evolution is not completely understood hitherto. Here ZnS is chosen as the model catalyst to study this and are prepared by hydrothermal treatment of ZnS(en) 0.5 precursor. ZnS nanoparticles exhibit high production yield of solar fuels due to the formation of internal Sphalerite-Wurtzite phase junction within a single particle. The predominant product of H 2 can reach a yield as high as 31.5 mmol/g-cat after 4-h reaction, meanwhile with a high CO yield of 279.3 μmol/g-cat. The mechanism is proposed from both dynamic (adsorption/desorption of reactants/products) and thermodynamic (redox potential, change in Gibbs free energy of key intermediates) point of view. This work not only provides useful information on the reaction selectivity between CO 2 reduction and H 2 evolution, but also pave a way to adjust the yield of a specific product upon photocatalysis.
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