查找使用阿拉丁产品的科研文献

Fabrication of high-sensitivity Bi0.2-xCexSr0.5La0.3TiO3 (0

Fabrication of a preferentially [001]-oriented Sb2Se3 thin film on diverse substrates and its application in photoelectrochemical water reduction

Hongpeng Zhou,Menglei Feng,Peiyuan Li,Xiangnan Gong,Dingke Zhang,Shijian Chen

Layered Sb2Se3 consists of infinite chains of repeating Sb4Se6 units stacked along the c-axis via Sb–Se covalent bonds, whereas they are linked by van der Waals force along the a-axis and b-axis. It usually tends to grow along the [hk0] orientation with low surface energy. However, [001]-oriented growth, which efficiently enhances charge transport, is often considered unstable due to its high surface energy. Herein, we propose a growth method to fabricate Sb2Se3 thin films with the preferential [001]-orientation on various substrates (Mo, MoSe2, SLG, NiO, SiO2 and FTO). This crystal facet design of preferentially [001]-oriented Sb2Se3 exposes the majority of the nanoribbons vertically aligned to the substrate, and thus maximally improves the charge transport, which may find applications in diverse optoelectronic devices. We confirmed their performance in photoelectrochemical water reduction. The preferentially [001]-oriented Sb2Se3 photocathode exhibited an impressive photocurrent density of −20.5 mA cm−2 at 0 V vs. RHE and a maximum photocurrent density of −28 mA cm−2 at −0.2 V vs. RHE under 1 sun AM 1.5 G illumination. Thus, the successful use of this [001]-Sb2Se3 photocathode paves the way for the development of high-efficiency Sb2Se3-based devices for optoelectronic applications.

Assembly of ordered polyaniline-graphene hybrid nanomaterials based on poly(2-methoxyaniline-5-sulfonic acid) functionalized graphene nanosheets

Qiang Zhao,Junhua Chen,Fubin Luo,Lu Shen,Ying Wang,Kun Wu,Mangeng Lu

Nanostructure of ordered polyaniline-graphene (PANI-rGO PMAS ) hybrid nanomaterials is assembled based on poly(2-methoxyaniline-5-sulfonic acid) (PMAS) functionalized reduced graphene oxide (rGO PMAS ) nanosheets. The presence of PMAS not only improves dispersibility of reduced graphene oxide nanosheets, but also plays a key role for heterogeneous nucleation of polyaniline (PANI) nanorods . The formation mechanism of ordered PANI-rGO PMAS hybrid nanomaterials was studied in details by using field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM) and ultraviolet-visible spectrophotometry (UV–vis). The conductivity of PANI-rGO PMAS hybrid with 17   wt% rGO PMAS is as high as 4480   S/m, compared with 2.93   S/m for pure PANI. The cyclic voltammetry tests indicate that, PANI-rGO PMAS containing 2   wt% rGO PMAS possesses fast response to redox reactions and excellent reversible stability. It has a high specific capacitance of 385   F   g −1 at the scan rate of 10   mV   s −1 with potential ranges from −0.2 to 0.8   V. This ordered polyaniline-graphene hybrid has potential applications for flexible supercapacitors, sensors, batteries, electromagnetic materials and thermoelectric materials, etc.

Flexible quantum dot-sensitized solar cells with improved efficiencies based on woven titanium wires

Yitan Li,Lin Wei,Cuncun Wu,Chang Liu,Yanxue Chen,Hong Liu,Jun Jiao,Liangmo Mei

Uniform zinc oxide (ZnO) nanosheet arrays were grown on woven titanium wires using a low temperature hydrothermal method. Photoanodes were prepared by depositing CdS and CdSe quantum dots onto the ZnO nanosheet arrays by a successive ionic layer adsorption and reaction (SILAR) method. Solar cells were assembled using these nanostructured photoanodes and their photovoltaic performance was characterized. The effect of using SILAR cycles for the deposition of quantum dots on the performance of these nanostructured solar cells was investigated systematically. The overall light-to-electricity conversion efficiency of 0.98% was achieved under 100 mW cm−2 illumination for flexible CdS/CdSe co-sensitized solar cells using conventional Pt foils as counter electrodes. To further improve the performance of the flexible solar cells, PbS and Cu2S counter electrodes based on Pb and Cu foils were fabricated. The best conversion efficiencies of flexible CdS/CdSe co-sensitized solar cells using Cu2S and PbS counter electrodes were 3.4% and 2.5%, which demonstrated a significant enhancement in values for short circuit current, open circuit voltage, and fill factor compared to those obtained with the commonly used Pt and Au electrodes.

Enhanced electrochemical performance of a cost-effective Sm2O3-coated spinel LiNi0.5Mn1.5O4 cathode for high-voltage lithium-ion batteries

Zhengwu Wang,Yannan Zhang,Bao Zhang,Dong Yang,Kai Zhou,Yixue Huang,Fei Wang,Jianguo Duan,Xianshu Wang,Peng Dong,Yingjie Zhang

Spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) has gained significant attention as a promising cathode material for lithium-ion batteries due to its high working voltage (>4.7 V) and energy density . However, challenges such as electrolyte decomposition-induced material interface erosion and transition metal dissolution under high operating voltage hinder its commercial use. In this study, a thin and uniform Sm 2 O 3 layer has been successfully deposited on the surface of LNMO using a wet chemical method . A comprehensive investigation of surface morphology , crystal structure, and electrochemical performance of the modified LNMO is conducted. The results demonstrate that the Sm 2 O 3 surface modification acts as a robust multifunctional protective layer, effectively shielding against hydrofluoric acid-induced chemical attack and enhancing the migration efficiency of lithium ions . Notably, the capacity retention rate of LNMO@Sm 2 O 3 (3 wt%) remains up to 88 % after 280 cycles, significantly surpassing the uncoated counterpart. The coated material exhibits a capacity of 114 mAh g −1 even under 10 C rate conditions. Moreover, the AC impedance values and manganese dissolution of the modified material in the organic electrolyte are considerably lower than those of the uncoated counterpart. Theoretical calculations strongly support the experimental findings, revealing higher Mn vacancy formation energy and density of states at the Fermi energy level for the Sm 2 O 3 -modified electrodes. This research contributes to the field of surface modification and paves the way for further enhancements in the electrochemical performance of other high-voltage manganese-based lithium-ion batteries (LIBs).

Long-side-chain type imidazolium-functionalized fluoro-methyl poly(arylene ether ketone) anion exchange membranes with superior electrodialysis performance

Junbin Liao,Jiajie Zhu,Shanshan Yang,Nengxiu Pan,Xinyan Yu,Chao Wang,Jun Li,Jiangnan Shen

Developing highly ion conductive and desirable electrodialysis (ED) performance anion exchange membranes (AEMs) is of great significance. In this work, we report a strategy for fabricating novel AEMs based on a series of fluoro-methyl poly(arylene ether ketone)s having long-side-chain imidazolium groups for ED. Having hydrophilic conductive flexible side-chain imidazolium groups and rigid hydrophobic backbone within AEM matrix, the optimized AEM (PAEK-60-im) shows low water uptake of 24.9% at 80 °C and desirable ion conductivity of 22.01 mS cm –1 at 30 °C. In NaCl removal application of ED, PAEK-60-im shows the NaCl removal ratio of 69.66% within 120 min, outperforming commercial AEM-Type II (68.98%). Accordingly, it has a higher current efficiency of 83.7% but lower energy consumption of 5.9 kWh kg –1 , compared with the commercial one (82.0%; 6.6 kWh kg –1 ). In particular, in selectrodialysis application, possibly owing to the synergistic effect of pore-size sieving effect resulting from macro-separation morphology and hydration energy difference of SO 4 2– ions (–1000 kJ mol –1 ) and Cl – ions (–317 kJ mol –1 ) in feeding solution, PAEK-60-im shows significantly superior monovalent anion perm-selectivity (Cl − /SO 4 2− ) of 7.70 at 30 min, relative to commercial anion-selective Neosepta ACS (5.27) and many other reported mono-valent anion selective AEMs having elegant surface modified layers. The superior ED performance of the homogeneous PAEK-60-im is suggestive of its potential separation application.

Constructing dimensional gradient structure of Na3V2(PO4)3/C@CNTs-WC by wolfram substitution for superior sodium storage

Shiqi Sun,Yanjun Chen,Jun Cheng,Zeyi Tian,Chao Wang,Guangping Wu,Changcheng Liu,Yanzhong Wang,Li Guo

Na 3 V 2 (PO 4 ) 3 (NVP) has gained enormous attentions due to the high capacity and voltage platform. Nevertheless, poor intrinsic electronic conductivities severely restrict the further development. Herein, a feasible strategy to construct unique dimensional gradient structure of the wolfram doped NVP is proposed via a facile sol–gel method. The introduction of W 6+ with the smaller ionic radius parallelized with local V 3+ ions could stabilize the open NASICON structure of NVP and generate vast of beneficial holes to accelerate the electronic transportation. Notably, the wolfram can combine with the superfluous carbon layer and form the new conductive WC phase to further promote the electronic conductivity. Meanwhile, the coated carbon layers and enwrapped CNTs construct an effective conductive framework for accelerated electronic migration. The twining CNTs promote to inhibit the growth of the sintered grains, reducing the particle size to provide shortened pathway for the migration of Na + . Distinctively, the modified Na 2.97 V 2.99 W 0.019 (PO 4 ) 3 /C@CNTs (W0.01-NVP) composite delivers a superior electrochemical performance. Significantly, it can submit a high reversible capability of 112.5 mAh g −1 at 5C with retaining 86% initial capacity over 500 cycles. As for a super high rate of 50C, it reveals an incredible capacity of 92.6 mAh g −1 and remains 84.5 mAh g −1 over 400 cycles, corresponding to a high retention of 91.30%. The superior electrochemical performance is derived from the enhanced crystal structure resulted from wolfram substitution and the beneficial dimensional conductive system consisting of new WC phase, coated carbon layers and enwrapped CNTs.

In-situ-derived carbon coated sea urchin-like Na3V2(PO4)3 from V2C MXene for high-performance capacitive deionization

Lanlan Yu,Ningning Liu,Baojun Liu,Fei Yu,Jie Ma

Cathode materials with high capacity and cyclic durability are urgently needed for capacitive deionization . Na 3 V 2 (PO 4 ) 3 is an emerging pseudocapacitive candidate for this process on account of its high capacity and Na + reversible insertion, while it suffers from the intrinsic low electrical conductivity and small electrolyte-accessible surface area. Herein, a sea urchin-like Na 3 V 2 (PO 4 ) 3 @carbon (NVP@C) compound material was synthesized from MXene-V 2 C via hydrothermal method followed by annealing treatment, and then assembled as capacitive deionization (CDI) electrode material . Benefiting from three-dimensional sea urchin-like structure, where the nanoneedles of NVP@C serve as fast transport channel for Na + , NVP@C performed high specific capacity (437 F g −1 at 5 mV s −1 ) and fast ionic diffusion kinetics. Moreover, the NVP@C showed attractive desalination performance as cathode material for CDI, achieving a remarkable adsorption capacity of 74.0 mg g −1 in a NaCl salt solution (1000 mg L −1 ) and long life cycle stability. The present work provides a novel perspective to construct practical redox-active and stable CDI electrode with 3D structure from MXene for highly capacitive and durable desalination application .

Hierarchical mesoporous Li2Mn0.5Fe0.5SiO4 and Li2Mn0.5Fe0.5SiO4/C assembled by nanoparticles or nanoplates as a cathode material for lithium-ion batteries

Xiaolei Jiang,Huayun Xu,Jing Liu,Jian Yang,Hongzhi Mao,Yitai Qian

Hierarchical mesoporous Li 2 Mn 0.5 Fe 0.5 SiO 4 consisted of nanoparticles or nanoplates has been successfully synthesized for the first time by a hydrothermal method . Their carbon-coated composites are obtained by a heat treatment in the presence of citric acid. These composites were characterized by powder X-ray diffractometry, scanning and transmission electron microscopy , Raman spectroscopy , and thermogravimetric analysis . The lithium storage capacity and cycling performance of the optimized Li 2 Mn 0.5 Fe 0.5 SiO 4 /C composite are greatly enhanced when tested as a cathode material in lithium-ion batteries (LIBs). It exhibits a discharge capacity of 125   mAh   g −1 after 60 cycles at a rate of 0.1   C. This superior electrochemical property could be ascribed to high purity and mesoporous structure of Li 2 Mn 0.5 Fe 0.5 SiO 4 , which greatly enhances the electronic conductivity as well as the diffusion coefficient of lithium ions .

Enhanced Electrochemical Performance of LiFePO4 as Cathode for Lithium Ion Battery by Codoping with Titanium and Nitrogen

Wei Su,Kaiqi Xu,Guobin Zhong,Zengfu Wei,Chao Wang,Yuezhong Meng

Titanium and nitrogen codoped LiFePO 4 was synthesized via a simple solid state reaction using TiN as the dopant source. The morphology, structure, valence state and electrochemical performance of all the samples were investigated and compared with the undoped LiFePO 4 . The results showed that the codoped samples maintained an olivine structure with modified lattice parameters and exhibited a prominent improved electrochemical performance. Among all the codoped samples, LiFe 0.94 Ti 0.04 PO 4-σ N 0.04 showed the best rate capability of 108.1 mAh g -1 even at a high rate of 5 C and exhibited a capacity retention of about 94% after 100 cycles at 1 C.

Molten drawing inorganic ductile Ag2S0.7Te0.3 fibers with high thermoelectric performance and stability

Wei Lianghuan,Dong Tianhao,Cui Yongpeng,Zhu Shengjie,Si Jianxiao

One potential application for flexible thermoelectric (TE) devices based on inorganic ductile fiber materials is the development of self-powered wearable electronics. In the work, the molten drawing method was employed for fabricating inorganic ductile Ag 2 S 0.7 Te 0.3 fibers. The output voltage and maximum output power of the single fiber are 3.3 mV and 837.4 nW, respectively, under a temperature difference of 50 K. The Ag 2 S 0.7 Te 0.3 fiber shows outstanding stability performance in the service stability test with a critical electric density of 36 A cm −2 and exhibits a tensile strain of 5%. The high temperature sensitivity of the Ag 2 S 0.7 Te 0.3 fibers TE device demonstrates the application potential in wearable electronics products.

Cation ordering/disordering effects upon photocatalytic activity of CrNbO4, CrTaO4, Sr2CrNbO6 and Sr2CrTaO6

Meilin Lv,Shuang Ni,Zhuo Wang,Tongcheng Cao,Xiaoxiang Xu

Doping has generally been served as one of the most efficient strategies for the improvement of wide band gap semiconductor photocatalysts . However, atomic arrangements of doped elements in the host crystal structure have often been overlooked, particularly during the investigation and evaluation of dopant functionality. It is known that electronic structures of a semiconductor are profoundly controlled by atomic occupancies in different crystallographic positions. Knowledge about dopant accommodations in the crystal structure and their influence towards photocatalytic performance is highly desired. Here, we investigated four compositional and structural relevant compounds CrNbO 4 , CrTaO 4 , Sr 2 CrNbO 6 and Sr 2 CrTaO 6 with the aim to study the effects of cation ordering/disordering upon their photocatalytic activity . Our results showed that ordered cations, namely Cr and Nb/Ta, are detrimental to the photocatalytic performance. Theoretical calculations indicate that cation ordering would enlarge the band gap and inhibit charge transfer between Cr and Nb/Ta. Our findings imply that ordered dopants in photocatalytic materials would severely offset the benefits of doping and might be a reason for the decreased activity at high doping levels often encountered.