查找使用阿拉丁产品的科研文献

Crystal structure and luminescence of Cs-Pb-Sn-Br nanocrystals

Zhao Yubin,Li Meng,Matras-Postolek Katarzyna,Yang Ping

Sn 2+ ions were introduced in Cs-Pb-Br nanocrystals (NCs) to test the change of crystal structure and photoluminescence (PL) property. In the cases of Sn/Pb ratios less than 20%, the CsPb 1- x Sn x Br 3 NCs revealed CsPbBr 3 crystal structure. With increasing the Sn/Pb ratio, Cs-Pb-Sn-Br NCs exhibited a mixture phase of CsPbBr 3 and Cs 4 PbBr 6 . The NCs show bright PLQYs (87%) for Sn/Pb molar ratio of 30%. This is ascribed to little amount Cs 4 PbBr 6 decreased the electrons and holes non-radiation recombination of CsPbBr 3 . With increasing the Sn/Pb ratio to 80%, the Cs 4 Pb 1- x Sn x Br 6 NCs exhibited pure Cs 4 PbBr 6 phase structure. Furthermore, a weak blue-emitting peak around 450 nm was observed for the Cs 4 Pb 1- x Sn x Br 6 NCs. This confirms that Sn 2+ ions were successfully introduced into Cs 4 PbBr 6 structure. The morphologies of samples changed from initial cubic to hexagonal with increasing Sn/Pb ratios from 20 to 80%. The excitons and free carrier dynamics of the NCs were discussed. Graphical abstract

Synthesis, crystal structures of ASb(SO4)2 (A = K, Cs)

Xiao Zhao,Dajiang Mei,Jingli Xu,Yuandong Wu

The reactions of A 2 SO 4 ( A  = K, Cs) and Sb 2 O 3 with H 2 SO 4 (98%) yielded single crystals of A Sb(SO 4 ) 2 ( A  = K, Cs). The crystal structures were investigated by single crystal X-ray diffraction. KSb(SO 4 ) 2 crystallizes in the monoclinic space group P 2 1 / c (No. 14) with lattice parameters a  = 10.6745(18), b  = 7.1579(12), c  = 8.7597(15) Å, β = 91.466(3) ° , V  = 669.1(2) Å 3 , Z  = 4. CsSb(SO 4 ) 2 crystallizes in the orthorhombic space group P 2 1 2 1 2 1 (No.19) with lattice parameters of a  = 5.2429(8), b  = 9.5942(16), c  = 14.850(2) Å, V  = 746.98(20) Å 3 , Z  = 4. Both compounds show the Sb 3+ cations in same seesaw-type coordination of oxygen atoms from different SO 4 2 − ${{\text{SO}}_4}^{2-}$ anions, but exhibit complex two-dimensionally and one-dimensionally linked anionic structures. The alkali cations are located between the layers or chains. The compounds were characterized with FT-IR spectra and solid state UV–vis–NIR diffuse reflectance spectroscopy . The band gaps were estimated at 4.64 eV for KSb(SO 4 ) 2 and 4.68 eV for CsSb(SO 4 ) 2 .

Synthesis, fabrication and properties research of CS-mPEG-AN nanocomposite

KangRui Wang,Hong Tang,Hongjie Chen,Xiaorong Huang,Ying Fang,Rongrong Men,Jie Gao,Yue Wang,Yang Wang,ChengHong Huang

Influence of phase transition on stability of perovskite solar cells under thermal cycling conditions

Jiang He,Tianhui Li,Xueping Liu,Hang Su,Zhiliang Ku,Jie Zhong,Fuzhi Huang,Yong Peng,Yi-Bing Cheng

In this research, we investigated the influence of phase transition in four standard perovskite materials on the device stability under thermal cycling (TC) condition, which is listed in International Electrotechnical Commission (IEC) stability tests criteria. The evolution of morphology, phase structure and charge carrier dynamics of four type perovskite materials throughout thermal cycling were analyzed. It was found that the cubic to tetragonal phase transition of MAPbI 3 caused the quick degradation of the device, the α to δ phase transition in FAPbI 3 and FA 0.6 MA 0.4 PbI 3 resulted in sustained efficiency loss, while the FA 0.9 Cs 0.1 PbI 3 was more stable compared to above three perovskites under the same test condition. The FA 0.9 Cs 0.1 PbI 3 device retained nearly 88% of its initial efficiency after 200 temperature cycles between −30 °C and 85 °C, which could be ascribed to its successful stabilization of perovskite structure.

A highly stable hole-conductor-free CsxMA1-xPbI3 perovskite solar cell based on carbon counter electrode

Shaowei Wang,Huijing Liu,Hari Bala,Beibei Zong,Liwen Huang,Zu-an Guo,Wuyou Fu,Bo Zhang,Guang Sun,Jianliang Cao,Zhanying Zhang

Hole-conductor-free perovskite solar cells (PSCs) based on carbon counter electrode were fabricated under a high humidity air environment and the performance of Cs + doping in methylammonium lead iodide perovskite (Cs x MA 1- x PbI 3 ) as light absorber layer was investigated and discussed. After the doping of Cs + , the excellent morphology, crystallinity and light absorption of perovskite thin films were observed by corresponding test methods, leading to the higher short-circuit current density and open-circuit voltage in the relevant devices. However, excessive Cs + doping can damage the performance of PSCs. The optimized device with x  = 0.05, exhibited open-circuit voltage of 956 mV, short-circuit current density of 21.73 mA/cm 2 , fill factor of 0.509 and the power conversion efficiency ( PCE ) of 10.57% under AM 1.5G illumination showing a 16% enhancement than pure MAPbI 3 devices. The PSCs based on carbon counter electrode also showed high stability, despite being stored under ambient air without encapsulation. After 1000 h, the Cs 0.05 MA 0.95 PbI 3 devices maintained more than 90% of their initial PCE . The long-term stability can be attributed to the synergistic interaction of Cs + on the solid solution strengthening of MAPbI 3 and the protection of the hydrophobic carbon electrode on the perovskite active layer.

A dual-functional bimetallic-organic framework nanosensor for detection and decontamination of lachrymator in drinking water

Xiao Lian,Bing Yan

A novel nanosensor (MOFs-SH) was constructed from a nanorod bimetallic-organic frameworks, exhibits highly selective and sensitive recognition and detection of 2-chlorobenzalmalononitrile (CS) lachrymator. By combining the high selectivity of thiol-ene click reaction and the strong luminescence properties of lanthanide metal-organic frameworks, MOFs-SH has demonstrated high selectivity and sensitivity towards CS, with satisfactory rapidity, accuracy, reliability and practicality. Mercaptan was used as a connector between MOFs and CS molecule by coordination bond and click reaction, thus induced a luminescence quenching based on an acceptor-excited photoinduced electron transfer mechanism. The electron transfer process between MOFs-SH and CS led to significant fluorescence quenching of the nanosensor, by which CS could be sensed, and high detection sensitivity up to 32.1 ppb was attained. Moreover, the nanosensor was successfully applied to determine CS in drinking water samples, and surprisingly shows the ability to purify polluted drinking water which polluted by CS (Q a = 425 mg g -1 ). This first reported CS sensing and decontaminate platform have been promising application for highly sensitive detection and postwar water purification of CS toxicant.

3D gel printing of magnetic hydrogel scaffolds assisted by in-situ gelation in a water level-controlled crosslinker bath

Jing Duan,Tao Lin,Hongyuan Liu,Jing Xu,Huiping Shao

Polyvinylalcohol/chitosan (PVA/CS) is an excellent dual-network hydrogel material, but some significant challenges remain in fabricating composites with specific structures. In this study, 3D gel printing (3DGP) combined with a water-level controlled crosslinker bath was proposed for the rapid in-situ prototyping of PVA/CS/Fe 3 O 4 magnetic hydrogel scaffolds. Specifically, the PVA/CS/Fe 3 O 4 hydrogels were extruded into the crosslinker water to achieve rapid in-situ gelation , improving the printability of hydrogel scaffolds. The effect of the PVA/CS ratio on the rheological and mechanical properties of dual-network magnetic hydrogels was evaluated. The printing parameters were systematically optimized to facilitate the coordination between the crosslinking water bath and printer. The different crosslinking water baths were investigated to improve the printability of PVA/CS/Fe 3 O 4 hydrogels. The results showed that the printability of the sodium hydroxide (NaOH) crosslinker was significantly better than that of sodium tripolyphosphate (TPP). The magnetic hydrogels (PVA: CS= 1: 1) crosslinked by NaOH had better compressive strength , swelling rate, and saturation magnetization of 1.17 MPa, 92.43%, and 22.19 emu/g, respectively. The MC3T3-E1 cell culture results showed that the PVA/CS/Fe 3 O 4 scaffolds promoted cell adhesion and proliferation, and the scaffolds crosslinked by NaOH had superior cytocompatibility. 3DGP combined with a water-level controlled crosslinker bath offers a promising approach to preparing magnetic hydrogel materials.

Tm3+-doped Cs2Ag0.6Na0.4In0.9Bi0.1Cl6 microcrystals for thermometry

Sen Yang,Yinghao Wei,Qi Wang,Zhijun Sun,Ai-Hua Li

Lead-free double perovskites have superb luminescence properties for broad applications. However, increasing or improving near-infrared (NIR) photoluminescence (PL) is still a challenge. In this paper, a high-performance microcrystal is designed based on Tm 3+ heavily doped Cs 2 Ag 0.6 Na 0.4 In 0.9 Bi 0.1 Cl 6 (CANIBC), which realize both the self-trapped excitons (STEs) and Tm 3+ NIR emission. The emission mechanism and energy transfer (ET) process are studied by steady-state and time-resolved PL spectra. The ET efficiency from STEs to Tm 3+ can reach 38.3 %, and the NIR PL quantum yield of Tm 3+ can reach 22.7 %. Meanwhile, the PL spectra of Tm 3+ -doped CANIBC microcrystals (MCs) with different concentrations are used to investigate their temperature sensing properties based on both fluorescence intensity ratio (FIR) and lifetime. Based on the FIR, relative sensitivity ( S r ) can reach 2.93 % K −1 at 303 K. Moreover, based on lifetimes, S r can maintain more than 1.55 % K −1 from 303 to 453 K, and maximum S r can also achieve 2.38 % K −1 at 360 K. These excellent luminescence and sensing properties offer greater development potential in the field of NIR phosphor and thermometry.

Fabric-based hydrophobic humidity sensors for measuring human insensible sweat rate

Zhenting Wu,Ruifang Liu,Shaohua Xing,Qing Hao,Long Ba

Sweat monitoring can reflect human health status, and insensible sweat is crucial for assessing skin barrier functions and physiological status. The development of a flexible, breathable, and insensible sweat rate sensor is still a challenge. Here we prepared a fabric-based humidity sensor for human insensible sweat rate monitoring. In which the CS/PVA/CNP composite material has a significant response to changes in humidity, the humidity-sensitive material and interdigital electrodes are encapsulated in the middle of two layers of hydrophobic fabrics, which effectively avoids the influence of external water on the sensor; and it is also breathable, ensures the wearing comfort. The sensor is integrated with wireless communication and powering module to monitor the insensible sweat rate at different body locations continuously. Human testing demonstrated the feasibility of the system to assess the insensible sweat rate of the body under different exercise conditions. Our sensor provides a low-cost device platform that offers new ideas for research in personalized medicine and smart clothing.

Investigation of the adsorption properties of U(VI) by sulfonic acid-functionalized carbon materials

Yunyun Bao,Jiang Chao,Liu Yan,Wang Changfu,Liu Jinbiao

In this study, sulfonic acid-functionalized carbon materials (CS-SO 3 H) was carbonized and functionalized by polyphosphazene (PZS). The morphology and structure were characterized by FTIR, XPS and SEM. The influences of pH, contact time, initial concentration and temperature of CS-SO 3 H for uranyl ions were investigated. Results indicated that the adsorption equilibrium time was about 20 min. The adsorption process was more consistent with the Langmuir isotherm and the pseudo-second-order model. In addition, the maximum adsorption capacity of CS-SO 3 H was about 341.98 mg/g. Moreover, the thermodynamic parameters of ΔG, ΔH and ΔS show that the uranium adsorption process was spontaneous and endothermic.

Preparation of CS-LS/AgNPs Composites and Photocatalytic Degradation of Dyes

Jiabao Wu,Xinpeng Chen,Aijing Li,Tieling Xing,Guoqiang Chen

Synthetic dyes are prone to water pollution during use, jeopardizing biodiversity and human health. This study aimed to investigate the adsorption and photocatalytic assist potential of sodium lignosulfonate (LS) in in situ reduced silver nanoparticles (AgNPs) and chitosan (CS)-loaded silver nanoparticles (CS-LS/AgNPs) as adsorbents for Rhodamine B (RhB). The AgNPs were synthesized by doping LS on the surface of chitosan for modification. Fourier transform infrared (FT-IR) spectrometry, energy-dispersive spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were used to confirm the synthesis of nanomaterials. The adsorption and photocatalytic removal experiments of RhB were carried out under optimal conditions (initial dye concentration of 20 mg/L, adsorbent dosage of 0.02 g, time of 60 min, and UV power of 250 W), and the kinetics of dye degradation was also investigated, which showed that the removal rate of RhB by AgNPs photocatalysis can reach 55%. The results indicated that LS was highly effective as a reducing agent for the large-scale production of metal nanoparticles and can be used for dye decolorization. This work provides a new catalyst for the effective removal of dye from wastewater, and can achieve high-value applications of chitosan and lignin.

Ultrafast aqueous Cs−ion storage kinetics in restacked 1T–MoS2 films

Zhiqiang Liu,Henghui Jin,Yongping Du,Weicheng Zhan,Leiming Lang,Guangxiang Liu,Jiangtao Yuan,Pan Feng,Li Tao,Jian Zhang,Guoqiang Luo,Changlin Dong,Jiajun Gu,Wenshu Chen

Restacked two-dimensional (2D) material thin films offer a promising approach for achieving high volumetric energy density supercapacitors, but their ultimate rate performance is constrained by electrolyte ion transport properties. This work systematically investigates the electrochemical behaviors and underlying mechanisms of restacked 1T−MoS 2 films in various aqueous electrolytes. In 1 M CsCl electrolyte, an 8.5-μm-thick 1T−MoS 2 film electrode exhibits ultrafast ion storage kinetics with a b -value of 0.94 and a remarkable volumetric capacitance ( C v ) of 221 F cm −3 at 1,000 mV s −1 , significantly outperforming other ionic systems. The electrode also demonstrates excellent cycling stability with 87% capacitance retention after 10,000 cycles at 10 A g −1 . Compared to reported advanced graphene, MXene, and oxide-based electrodes, the 1T−MoS 2 film electrodes in 1 M CsCl show an integrated advantage of ultrathin characteristic and ultrahigh C v under considerable high scan rates of 500 to 1,000 mV s −1 . Theoretical calculations reveal that Cs + possesses the lowest diffusion barrier between 1T−MoS 2 interlayers, where its weak solvation effect facilitates rapid ion storage kinetics. This work not only elucidates the ultrafast transport mechanism of Cs + within confined 2D spaces, but also provides insights into developing next-generation ultrafast energy storage devices with high volumetric energy densities through optimized electrolyte–electrode synergy. The electrochemical ion storage behaviors and underlying mechanisms of restacked 1T−MoS 2 film electrodes in various aqueous electrolytes were systematically investigated. The electrodes exhibit ultrafast charge storage kinetics in 1 M CsCl, demonstrating the combined advantages of ultrathin feature and ultrahigh volumetric capacitance at scan rates as high as 1000 mV s −1 , significantly outperforming state-of-the-art reported electrode materials. Download: Download high-res image (188KB) Download: Download full-size image