查找使用阿拉丁产品的科研文献

3D heterojunction assembled via interlayer-expanded MoSe2 nanosheets anchored on N-doped branched TiO2@C nanofibers as superior anode material for sodium-ion batteries

JiuWu Wang,Caini Yang,Siyao Chen,Yinping Wu,Xian Sun,Chenguang Huang,Rui Tang,Jiasheng Ke,Yi Dai,Yue Situ,Hong Huang

High-performance sodium-ion batteries (SIBs) are highly expected in the field of large-scale static energy storage due to the low expenditure and abundant sodium resource. However, the sodium storage performance of anode materials for SIBs has suffered from the foot-dragging reaction kinetics arising from large-size Na + during intercalation/deintercalation, which imposes more stringent requirements on the morphology and structure of the potential anode electrodes. Herein, we successfully designed and synthesized a three-dimensional (3D) heterojunction as anode material for SIBs, which assembled by interlayer-expanded MoSe 2 nanosheets perpendicularly anchored on the nitrogen-doped branched TiO 2 @C nanofibers (MoSe 2 @NBT@CNFs). Not only does the branched TiO 2 @C nanofibers suppress the severe self-aggregation of MoSe 2 nanosheets but also buffer the volume expansion during the cycling process. Moreover, an expanded interlamellar distance of MoSe 2 nanosheets accelerate sodium ion diffusion, and strong chemical interactions between MoSe 2 nanosheets and carbon nanofibers are conducive to improve the charge-transfer kinetics and reinforce the structural durability. As might be expected, the MoSe 2 @NBT@CNFs anode can deliver excellent cycling performance with high reversibility (315.2 mAh g 1 after 800 cycles at 2 A g 1 ) and remarkable rate capability (194.2 mAh g 1 at 30 A g 1 ). The rational design strategy could offer guidance for developing high-performance metal chalcogenide-based electrode materials for SIBs.

Surface iodine modification inducing robust CEI enables ultra-stable Li-Se batteries

Mingran Zhou,Wenda Dong,Ao Xu,Zhiwen Yin,Zhi-Yi Hu,Xinling Wang,Liang Wu,Lihua Chen,Yu Li,Bao-Lian Su

Lithium-selenium batteries (LSeBs) have attracted increasing attention due to their excellent electronic conductivity and high theoretical specific capacity. However, there are still difficult problems such as low utilization rate and fast capacity decay in the actual application process. Herein, a surface iodine modified three-dimensional (3D) nano hollow carbon fiber (I-NHCF) network is designed and synthesized as Se host (Se@I-NHCF) for highly stable LSeBs. The surface iodine species induce the formation of robust cathode electrolyte interface (CEI), thus preventing the transformation of amorphous selenium to low-activity crystalline selenium and enabling stable electrochemical performance. Moreover, the surface iodine species promote rapid charge transfer, enhancing the chemical reaction kinetics and improving the utilization of the active Se species. As a result, the Se@I-NHCF cathode exhibits superior specific capacity of 581.8 mAh g −1 with a high stability (0.0054% capacity decay per cycle) after 500 cycles at 1C, and an excellent rate performance of 567.6 mAh g −1 at 2C. This work addresses the problem of rapid capacity decay by the formation of uniform and robust CEI to conserve highly reactive amorphous Se species, improve Se utilization, and achieve ultra-stable Li-Se batteries with high energy and long cycle life.

CoSe2 nanoparticles anchored on porous carbon network structure for efficient Na-ion storage

Hanhao Liu,Dan Li,Honglang Liu,Xu Wang,Yaoxin Lu,Chao Wang,Li Guo

Cobalt selenide , as a star material in battery industry, has attracted much attention. However, when it is applied solely in sodium ion batteries , it will cause large volume expansion and material agglomeration, which will seriously affect the overall performance of batteries. In this work, we use ice bath impregnation to combine CoSe 2 nanoparticles with porous nitrogen-doped carbon networks (NC) as advanced anodes for ultra-long cycle life sodium ion batteries (SIBs). CoSe 2 nanoparticles are evenly attached to NC with strong interfacial contacts in CoSe 2 @NC. The strong contact of CoSe 2 on the porous carbon network, along with the carbon network's unique network cross-linking structure, results in rapid electron transfer and Na ion diffusion kinetics of CoSe 2 @NC, resulting in superior electrochemical performance . Besides, we have synthesized CoSe 2 @NC with different loading by changing Co 2+ concentration. The results show that CoSe 2 @NC anode thus provides a high reversible capacity of 406 mAh/g. In addition, at high current 5 A/g, it can keep a reversible capacity of 300 mAh/g after 4500 cycles with an average capacity loss of less than 0.01 % per cycle. The excellent anchoring structure enables it to form stable solid electrolyte film (SEI) and reduce the amount of dead sodium in the first charge–discharge process, showing high Initial Coulombic Efficiency (ICE) (89.2 %). Finally, CoSe 2 @NC and Na 3 V 2 (PO 4 ) 3 (NVP) are assembled into a full cell and the results shows an ultra-long cycle stability at 0.1 A/g. This strategy will facilitate the application of transition metal selenides in next-generation energy storage systems.

Effect of Different Ligands Coating on the Photovoltaic Performance of CdSe Quantum Dot-Sensitized Solar Cells

Yexin Chen,Shibing Zou,Wenhua Zou,Dongyang Wang,Junhong Duan,Weiqing Liu,Huaming Wu

Stainless steel mesh-based CoSe/Ni3Se4 heterostructure for efficient electrocatalytic overall water splitting

Hongbo Zhou,Dongxu Zhang,Weixuan Dong,Chunxing Zhou,Tianyao Jiang,Yashu Liu,Chungui Tian,Yanhong Liu,Yu Liu,Baodong Mao

The construction of high-efficiency bifunctional electrocatalysts is still a main challenge for hydrogen production from water splitting, in which comprehensive structure regulation plays a key role for synergistically boosting the intrinsic activity and charge collection. Here, we used a two-step hydrothermal method for construction of an interjaculated CoSe/Ni 3 Se 4 heterostructure from NiCo LDH nanosheets grown on stainless steel (SS) meshes as bifunctional electrocatalysts for overall water splitting. The SS meshes containing Fe and Ni act as an excellent 3D scaffold for catalyst growth and charge collection. The SS@CoSe/Ni 3 Se 4 composite exhibits outstanding electrocatalytic performances with low overpotentials of 97 mV for hydrogen evolution and 230 mV for oxygen evolution to reach a current density of 10 mA cm −2 , respectively. Moreover, by using SS@CoSe/Ni 3 Se 4 as both the cathode and anode , the assembled electrolyze only required 1.55 V to reach 10 mA cm −2 for overall water splitting. The outstanding performance of SS@CoSe/Ni 3 Se 4 benefits from the synergy between excellent charge collection capability of SS meshes and the abundant active sites at the CoSe/Ni 3 Se 4 heterointerface formed with the in-situ conversion of NiCo LDH nanosheets. Electrochemical active surface area and impedance spectrum indicate that the CoSe/Ni 3 Se 4 loaded on SS has the most abundant electrochemically active sites and the smallest electrochemical resistance, thereby exposing more active sites and enhancing the charge transfer to promote the catalytic activity . By integrating the delicate nanoscale heterostructure engineering with the microscale SS mesh scaffold, our work provides a new perspective for the preparation of high-performance and cheap electrocatalysts that are easy to be integrated with industrial applications.

Fast synthesis and thermoelectric properties of BixCu2−3xSe0.95Te0.05 (x = 0, 0.001, 0.002, 0.003, 0.004)

Xue Lisha,Wang Yuan,Zhu Shuangmei,Mao Qianhui,Jia Xiaopeng,Zhang Yuewen

We have synthesized the quaternary copper selenide Bi x Cu 2−3 x Se 0.95 Te 0.05 compounds by high-pressure followed with ball milling method and investigated their thermoelectric properties. The crystal structure and element doping are characterized and verified by the X-ray diffraction, high-resolution transmission electron microscope and X-ray photoelectron spectroscopy. Compared with other samples, the samples with x  = 0.001 and 0.002 have larger layered grain size and smaller grain boundary. This may lead to the reduction of resistivity in a wide temperature range, thus realizing the optimization of electronic characteristics. The dislocation-induced lattice strain fluctuations may cause the abrupt thermal conductivity, which is contrary to the previous results. Eventually, a peak value of zT  = 1.03 at 873 K is obtained for Bi 0.001 Cu 1.997 Se 0.95 Te 0.05 and Bi 0.002 Cu 1.994 Se 0.95 Te 0.05 .

Near-infrared photon upconversion and solar synthesis using lead-free nanocrystals

Liang Wenfei,Nie Chengming,Du Jun,Han Yaoyao,Zhao Guohui,Yang Fan,Liang Guijie,Wu Kaifeng

Near-infrared-to-visible photon upconversion holds great promise for a diverse range of applications. Current photosensitizers for triplet-fusion upconversion across this spectral window often contain either precious or toxic elements and have relatively low efficiencies. Although colloidal nanocrystals have emerged as versatile photosensitizers, the only family of nanocrystals discovered for near-infrared upconversion is the highly toxic lead chalcogenides. Here we report zinc-doped CuInSe 2 nanocrystals as a low-cost and lead-free alternate, enabling near-infrared-to-yellow upconversion with an external quantum efficiency reaching 16.7%. When directly merged with photoredox catalysis, this system enables efficient near-infrared-driven organic synthesis and polymerization, which in turn solves the issue of reabsorption loss for nanocrystal-sensitized upconversion. Moreover, the broadband light capture of these nanocrystals enables very rapid reactions under indoor sunlight. Extending the reach of ‘solar synthesis’ into the near-infrared may realize the century-long dream of conducting high-added-value chemical transformations using sunlight.

A novel and sensitive ratiometric fluorescent quantum dot-based biosensor for alkaline phosphatase detection in biological samples via the inner-filter effect

Penghui Hu,Ruiyan Huang,Ye Xu,Tengfei Li,Jun Yin,Yu Yang,Yuan Liang,Xiaohan Mao,Li Ding,Chang Shu

Alkaline phosphatase (ALP) is an important biomarker whose abnormal level in activity is associated with hepatobiliary, skeletal, and renal diseases as well as cancer. Herein, we synthesized ZnSe@ZnS quantum dots (ZnSe@ZnS QDs) and Mn-doped ZnS quantum dots (Mn:ZnS QDs) as fluorophores to establish the ratiometric fluorescent assay for ALP activity detection in biological samples. p-Nitrophenyl phosphate (PNPP) was used as a substrate for ALP, and the overlaps between absorption spectra of PNPP and excitation spectra of QDs resulted in sharp fluorescence quenching. Under the catalysis of ALP, PNPP was hydrolyzed into p-nitrophenol (PNP), which caused a red shift of absorption band of PNPP and fluorescence recovery of Mn:ZnS QDs (585 nm). However, the overlaps between absorption spectra of PNP and emission spectra of ZnSe@ZnS QDs led a further quenching of ZnSe@ZnS QDs (405 nm). Therefore, the ratiometric fluorescent signals (F585/F405) were associated with activity of ALP based on bidirectional responses of QDs to the concentration of PNPP. Under the optimum conditions, the method exhibited a good linear relationship from 4 to 96 U per L (R2 = 0.9969) with the detection limit of 0.57 U per L. Moreover, the method was successfully applied for detecting the ALP activity in a complex biological matrix (human serum and HepG2 cells) with impressive specificity. In particular, the complicated chemical modifications of QDs and pretreatments of biological samples were not required in the whole detection procedures. Therefore, it not only provided a sensitive, specific and simple approach to clinical ALP activity detection, but it also provided support for early diagnosis of diseases.

Prussian blue analogs (PBA) derived heterostructure Zn-Fe bimetallic selenide nanospheres with high capacity sodium-ion storage

Tong Qi,Miao Jia,Qiong Yuan,Xu Zhang,Mengqiu Jia

Metal selenides have excellent theoretical capacity when used to store sodium . Compared with single metal selenides, bimetallic selenides stand out with excellent theoretical capacity, sufficient electrochemical reaction sites and good conductivity. In this work, Zn 3 [Fe(CN) 6 ] 2 prussian blue analogue nanospheres are prepared by a static method with PVP as dispersant, and then heterostructure ZnSe/FeSe nanospheres (ZnSe/FeSe NS) composite are prepared by gas-phase selenation. PVP is conducive to the formation of loose and porous structures and alleviate the volume expansion during sodium storage. In this structure, heterostructures can create abundant active sites and increase the electrochemical capacity. Therefore, the ZnSe/FeSe NS show high sodium storage capacity with a reversible capacity of 549.0 mAh g −1 at 100 mA g −1 and 436.8 mAh g −1 even after 100 cycles at 1 A g −1 . It also shows excellent rate performance with high stable capacities of 524.6, 486.1, 447.3, 431.1, 417.9 mAh g −1 in a series of current densities of 100, 200, 500, 1000, 2000 mA g −1 separately. The excellent capacity of the ZnSe/FeSe NS composite comes from the active sites provided by the heterostructure and the high conductivity provided by the built-in electric field.

Ratiometric fluorometric detection of Cu2+ through a hybrid nanoprobe composed of N-doped CQDs and l-cysteine-capped CdSe/ZnS QDs

Zhaofa Li,Quanxiu Zhou,Palanivel Sathishkumar,Liang Peng,Qunfang Wang,Feng Long Gu

The present work fabricated a novel dual-emission responsive ratiometric fluorescent hybrid nanoprobe using a mixture of blue fluorescence-emitting N-Doped Carbon Quantum Dots (N-CQDs) and red fluorescence-emitting l -cysteine-capped CdSe/ZnS Quantum Dots (Lcys-CdSe/ZnS QDs). The addition of Cu 2+ resulted in the strong and specific fluorescence quenching in Lcys-CdSe/ZnS QDs while N-CQDs retained their fluorescence intensity. Further exploration of the nanoprobe showed that the detection limit was 3.78 × 10 −9  M and the linear range was below 3.2 × 10 −6  M. The nanoprobe possessed excellent anti-interference in the Cu 2+ determination and its application was successful in natural water samples. Experimental results suggested that the superficial left cysteine (Lcys) combines with Cu 2+ causing static quenching. Results of density functional theory (DFT) computation explained that Cu 2+ has the greatest possibility to combine with surficial Lcys and furthermore illustrated the role of the combination in static quenching. The work showed one of origin of the selectivity of the nanoprobe and a potentially guidance to design high selective ratiometric fluorescent nanoprobes.

A ratiometric fluorescent nanoprobe based on CdSe quantum dots for the detection of Ag+ in environmental samples and living cells

Zhiqiang Zhou,Jianfang Cen,Naijia Jiang,Yu Sun,Zhouyang Li,Liyun Yang

With the widespread application of Ag + in modern life and industry, the potential hazardous effects of Ag + to environment and humans have attracted great concerns. Thus, effective and rapid strategies for Ag + detection are highly desirable. In this paper, a novel ratiometric fluorescence sensor using CdSe quantum dots (QDs) has been constructed for sensitive and selective detection of Ag + , which is based on the formation of Ag 2 Se QDs. CdSe QDs were initially prepared and showed single wavelength emission at 510 nm. When Ag + exists, a rising peak appeared at 650 nm and the emission at 510 nm declined, exhibiting distinct ratiometric fluorescence emission ( I 650 / I 510 ) characteristic with a linear response over the Ag + concentration range of 0.01–4 μM. Significantly, the fluorescence changed from green to red. The detection limit of the constructed sensor is 1.4 nM. Furthermore, the sensing assay can be successfully applied to detect Ag + in real water samples and living cells.

A solid-state Matryoshka doll-like microwave method for one-step rapid synthesis of composites of NiSe2 and nitrogen-doped porous carbon for sodium storage

Yayun Zheng,Xirui Kong,Lang He,Yi Song,Yan Zhao

A facile solid-state Matryoshka doll-like microwave strategy is developed to synthesize composites of NixSey and nitrogen-doped porous carbon (N–C). The crystal structures and morphology of NixSey/N–C are investigated with different feeding mass ratios of Ni/Se and at different microwave processing times. Thereinto, NiSe2/N–C is rapidly prepared in just 20 minutes. The physical–chemical properties of NiSe2/N–C are further investigated and the composite has shown good ion/electron transfer kinetics and structural stability for sodium storage. When employed as the anode of sodium ion batteries (SIBs), NiSe2/N–C shows a high reversible capacity of 374.4 mA h g−1 at 0.2 A g−1 and excellent cycling stability, retaining 95% of its initial capacity at 1.0 A g−1 after 2000 cycles. The good electrochemical performance is attributed to the synergistic effect between the highly active NiSe2 nanoparticles and the 3D conductive N–C frameworks, which expedites the charge-transfer rate and improves the reversibility of the charging/discharging reactions. The excellent Na+ storage kinetics of the NiSe2/N–C electrode results from its low adsorption energy of −0.94 eV and low energy barrier of 0.818 eV. This work provides a feasible microwave synthetic strategy to fabricate SIB electrode materials.