Small
·
2021
·Vol. 17
·期 50
·2103336
·
IF 13.281
Xuping Liu,Jihuai Wu,Chunyan Wang,Yuqian Yang,Deng Wang,Guodong Li,Yitian Du,Yuan Xu,Lei Zhang,Tingting Zhang,Lan Zhang
The carrier non-radiative recombination and instability of device caused by the inherent defects are main factors limiting development of perovskite solar cells (PSCs). During the fabrication process of a PSC device, perovskite films often produce Pb 0 and I 0 defects. This paper reports a strategy for synergistic optimization of perovskite films by defects passivation and surface modification. The doping of phthalide (PT) in the Pb-rich (CH(NH 2 ) 2 ) 1−x (CH 3 NH 3 ) x PbI 3 film can passivate lead cation defects, and the modification of 1-iodooctadecane (1-IO) can reduce halogen anion defects and improve stability of PSCs owing to its hydrophobicity. The PT and 1-IO optimized device achieves a power conversion efficiency (PCE) of 22.27%. The optimized PSCs remain 93.2% of the initial PCE when placed in air environment (relative humidity of 10%, 25 °C) more than 70 days. The PT and 1-IO synergistic optimization provides a novel strategy for improving the performance and stability of PSCs.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子
REACTIVE & FUNCTIONAL POLYMERS
·
2017
·
IF 3.151
Xuhai Xiong,Xinghua Ma,Ping Chen,Lu Zhou,Rong Ren,Siyang Liu
New aryl-ether-imide/phthalide-containing bismaleimide oligomers (MPEIBMI) with different molecular weight were designed and synthesized by adjusting the addition amount of diamine compound derived from o -cresolphthaleine, and dianhydride 4,4′-(4,4′-isopropylidene diphenoxy)-bis(phthalicanhydride) (mole ratio: 1.25/1.5/2.0). The chemical structures of the oligomers and their intermediate compounds were confirmed by Fourier transform infrared (FTIR) spectroscopy, nuclear magnetic resonance ( 1 H and 13 C NMR) spectroscopy and elementary analysis. X-ray diffraction (XRD) results showed a blunt diffraction peak, suggesting an amorphous structure. The oligomers exhibited good solubility in a variety of common organic solvents . The heat flow curves of the oligomers measured by differential scanning calorimeter (DSC) displayed a broad curing exothermic peak. The thermal stability and thermal mechanical properties of the cured resins were investigated by thermogravimetric analysis (TGA) and dynamic mechanical analysis (DMA). The results indicated that the introduction of phthalide cardo structure and imide rings into the polybismaleimide network could effectively improve the thermal properties. The glass transition temperature and initial thermal decomposition temperature were above 260 °C and 423 °C, respectively, and the residual weight percentages at 700 °C were all > 58%. The mechanical tests revealed that the cured MPEIBMI films had excellent tensile strength and good retention at the temperatures above 200 °C.
研究领域:
材料科学
·
化学工程
✓ 已验证
DOI
高影响因子
HIGH PERFORMANCE POLYMERS
·
2018
·
IF 1.047
Siyang Liu,Yuanying Wang,Ping Chen,Dongwei Xu,Xuhai Xiong,Xiaoyu Yan
Two novel n ≈ 1 oligomeric bismaleimide monomers containing phthalide cardo and cyano groups (PCBMI and MCBMI) were designed and synthesized. The chemical structures of the monomers were confirmed from proton nuclear magnetic resonance spectroscopy and Fourier transform infrared spectroscopy. Both BMIs exhibit good solubility in common organic solvents, enabling easy solution processing. Thermal curing behaviors of the monomers were investigated by differential scanning calorimetry, displaying broad exothermic peaks and large thermal processing windows. Furthermore, PCBMI/carbon fiber composites were prepared, with their thermal stability and mechanical properties investigated. Thermogravimetric analysis and test of interlaminar shear strength indicated that the thermal polymerization of cyano groups improved the heat resistance of BMI resins and enhanced the interfacial adhesion at higher temperature.
研究领域:
材料科学
·
化学工程
✓ 已验证
产品关联
DOI
高影响因子
ACS Catalysis
·
2023
·
IF 12.9
Dong Ji,Peng Guo,Yongjie Xi,Jinlei Li,Jia Wang,Tingting Wang,Fuwei Li
Selective tandem hydrogenation is a promising strategy for catalytic conversion of bulk raw materials with multifunctional groups into high-value-added chemicals via multiple-step reactions. Yet now, one of the current challenges is to develop a multifunctional and stable catalyst enabling the tandem catalysis rather than interrupting at any step reaction, particularly for supported nonprecious metal catalysts. In this work, we report tandem hydrogenation of bulk phthalic anhydride toward the one-pot synthesis of hexahydrophthalide, an emerging monomer of a recyclable polyester, over phosphorus-promoted Ni–Co bimetallic alloy nanoparticle catalysts. The surface composition of catalysts can be easily regulated by changing the Ni/Co molar ratio and the phosphorous functionalization strategy, which could then tune the product selectivity and enhance the stability of this tandem process. The optimal Ni3Co1@NC-P affords 88% selectivity for the desired product and demonstrates promising stability toward the tandem hydrogenation reaction. Systematic experimental and computational studies reveal that the adsorption strength of the intermediates and the ability of hydrogen activation can be altered by the formation of surface metallic Ni species, thus tuning the product selectivity. In addition, the oxidation resistance of Ni3Co1@NC-P was enhanced by the phosphorization treatment, which makes the bimetallic alloy successfully realize the tandem hydrogenation reaction. The finding of this work not only provides a convenient strategy to design and develop efficient and stable non-noble metal-based catalysts for selective tandem hydrogenation reactions, especially involving the hydrodeoxygenation reaction, but also fulfills the straightforward pathway for the preparation of degradable polyester monomer hexahydrophthalide.
研究领域:
催化化学
·
材料科学
·
计算化学
✓ 已验证
产品关联
DOI
高影响因子
CRYSTAL GROWTH & DESIGN
·
2024
·
IF 3.2
Jinjia Guo,Lei Xu,Mingjie Cai,Zhongxin Dong,Qiong Mu,Xiaoming Wang,Haibo Fan,Feng Teng,Xuexia He,Hui Jiang,Peng Hu
Organic charge-transfer cocrystals are composed of an electron-rich donor molecule and an electron-deficient acceptor molecule, which are bonded together by intermolecular noncovalent interactions such as π–π interactions, hydrogen bonds, halogen bonds, and charge-transfer interactions. These noncovalent interactions influence the cocrystal packing structures and the photoluminescence properties. Herein, four charge transfer cocrystals, pyrene-tetrafluorophthalic anhydride (TFPA), perylene-TFPA, pyrene-tetrachlorophthalic anhydride (TCPA), and perylene-TCPA, were grown by the slow cooling method and the influence of intermolecular noncovalent interactions on the photoluminescence properties were investigated. Cocrystals of pyrene-TFPA and pyrene-TCPA exhibit a yellow rod-like morphology, while both perylene-TFPA and perylene-TCPA exhibit red rod-like shapes. Results indicate that the C–H···X (X = F, Cl, or O) interactions, π–π interactions, and charge-transfer interactions are dramatically affected by the energy difference between the HOMO of the donor and the LUMO of the acceptor. Meanwhile, for the same acceptor molecules, the positions of the photoluminescence peaks of the cocrystals red-shifted with the enhancement of weak noncovalent interactions, which paved the way to tuning the optical properties of charge transfer cocrystals.
研究领域:
材料科学
·
化学
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产品关联
DOI
高影响因子
MACROMOLECULAR RESEARCH
·
2020
·Vol. 28
·期 5
·494-500
·
IF 2.047
Guo Xichao,Xiong Xuhai,Ren Rong,Chen Ping
In Part I of the paper, we have focused on the synthesis, characterization and solubility of three chain-extended bismaleimides containing aryl-ether-imide and phthalide cardo skeleton with different molecular weight (MPEIBMI-2.0, MPEIBMI-1.5 and MPEIBMI-1.25) and the thermal stability and thermal mechanical properties of their cured resins. In Part II of the paper, their high-temperature static viscoelasticity, shape memory (SM) performance and self-repairing behavior for micro-damages were investigated by dynamic mechanical analyzer and optical microscope. The creep test results exhibit the MPEIBMI-2.0 cured film has the strongest creep resistance at the same testing temperature due to the highest stiffness of its network structure, and the maximum allowable load of MPEIBMI-1.25 film at 200 °C reaches 15 MPa for 60 min creep experiment. The rate of stress relaxation for MPEIBMI-1.25 film is slower in spite of having relatively lower stress level. The MPEIBMI-1.25 film has the largest ultimate elongation at high temperature and this deformability confers it excellent shape memory (SM) ability. The shape fixity ratio reaches above 98% and the recovery rate is increased to above 96% from 94.5% after one SM cycle. The micro-damages on the surface of cured films could be repaired when heated to the temperature above their glass transition temperature, and the repairing temperature is increased with their crosslinking density to obtain perfect repairing efficiency.
研究领域:
材料科学
·
高分子化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）