查找使用阿拉丁产品的科研文献

A double crosslinking MXene/cellulose nanofiber layered film for improving mechanical properties and stable electromagnetic interference shielding performance

Shilu Luo,Tiantian Xiang,Jingwen Dong,Fengmei Su,Youxin Ji,Chuntai Liu,Yuezhan Feng

With the discovery of the two-dimensional (2D) MXene, it shows a great application potential in the field of electromagnetic interference (EMI) shielding, but the mechanical brittleness and easy oxidation of MXene limit its wide application. For this reason, a double crosslinking strategy is provided to solve the above problems in a nacre-like “brick-mortar” layered MXene/cellulose nanofiber (MXene/CNF) film. Typically, the film was firstly suffered by dopamine modification, then was further reinforced by secondary Ca 2+ bridging, so as to obtain excellent mechanical properties and antioxidative EMI shielding performance. Comparing with the single crosslinking, the double crosslinking strategy reveals a higher efficiency in improving the mechanical property. The mechanical strength and toughness of the double crosslinking MXene/CNF film can increase to 142.2 MPa and 9.48 MJ/m 3 , respectively. More importantly, while achieving good mechanical properties, the MXene composite film still holds a very stable EMI shielding performance of more than 44.6 dB when suffering from the oxidation treatment of high-temperature annealing, showing excellent anti-oxidation ability and environment tolerance. Therefore, this work provides a universal but effective double crosslinking strategy to solve the mechanical brittleness and easy oxidation of MXene-based composites, thus showing a huge potential in flexible EMI shielding applications.

Constructing titanium carbide MXene/reduced graphene oxide superlattice heterostructure via electrostatic self-assembly for high-performance capacitive deionization

Huiting Xu,Meng Li,Siqi Gong,Fan Zhao,Yang Zhao,Chunli Li,Junjie Qi,Zhiying Wang,Honghai Wang,Xiaobin Fan,Wenchao Peng,Jiapeng Liu

Capacitive deionization has attracted wide concern on account   of its high energy efficiency, low manufacturing cost and environmental friendliness . Nevertheless, the development of capacitive deionization is still impeded because of the scarcity of suitable electrode materials with superior performance. Herein, we successfully prepared the two-dimensional (2D) titanium carbide (Ti 3 C 2 T x ) MXene/ reduced graphene oxide (rGO) superlattice heterostructure by a facile electrostatic self-assembly strategy and systematically investigated its performance as capacitive deionized electrode materials. The unique 2D/2D superlattice heterostructure not only effectively alleviates the self-stacking problem of Ti 3 C 2 T x MXene nanosheets , but also endows the heterostructure with superior conductivity and fast ion diffusion rate. As a result, the MXene/rGO superlattice heterostructure exhibits an outstanding salt (Na + ) adsorption capacity (48 mg g − 1 ) at 1.2 V significantly superior to pristine Ti 3 C 2 T x MXene nanosheets, along with outstanding long-term cycling performance. Furthermore, the mechanism involved was elucidated through comprehensive characterizations. Therefore, this study offers a new pathway for designing high-performance electrode materials for capacitive deionization.

Persulfate activation of CuS@Ti3C2-based MXene with Bi-active centers toward Orange II removal under visible light

Qi Wang,Yu Mei,Ruoxue Zhou,Sridhar Komarneni,Jianfeng Ma

The Ti 3 C 2 -based MXene with unique lamellar nanostructure and high conductivity is expected to effectively improve photocatalytic ability of composites as a cocatalyst. Herein, two dimensional Ti 3 C 2 -based MXene nanosheets decorated with copper sulfide particles (CuS@MXene) were synthesized by hydrothermal treatment to boost catalytic persulfate (PS) activation under light, exhibiting remarkable reactivity and stability for the rapid removal of Orange II. The phase composition of CuS@MXene was detected by X-ray diffraction (XRD), the morphology of CuS@MXene was characterized by scanning electron microscope (SEM), and the results of X-ray photoelectron spectroscopy (XPS) proved the elemental composition and valence state of elements in the CuS@MXene. The dosage of PS and initial pH of solution were the main factors affecting the removal rate of Orange II, and the quenching experiment showed that 1 O 2 was the primary reactive species for the removal of Orange II in CuS@MXene -PS system. In addition, this study showed that CuS@MXene provided bi-active centers for PS activation, which was mainly attributed to the rapid charge transfer between dual electron-rich active centers of Cu and Ti. This system may be applicable to the degradation of other challenging organic pollutants .

Electrically conductive porous MXene-polymer composites with ultralow percolation threshold via Pickering high internal phase emulsion templating strategy

Zheng Zheng,Yongliang Zhao,Zhangfan Ye,Jianhua Hu,Haitao Wang

Hypothesis: Constructing a segregated network in electrically conductive polymer composites (ECPCs) is an effective method to lower the electrical percolation threshold. The segregated network structure can be formed naturally via polymerizing Pickering high internal phase emulsions (HIPEs) because solid particles are assembled at water-oil interfaces. However, most Pickering stabilizers show poor electrical conductivity . In this work, we propose a facile method to prepare lightweight ECPCs with well-controlled segregated structure via Ti 3 C 2 T x -stabilized HIPE templating. Experiments: Hydrophilic Ti 3 C 2 T x flakes are delicately hydrophobized with a double-chain cation surfactant . The morphology of Ti 3 C 2 T x flakes is investigated by transmission electron microscopy (TEM) and atom force microscopy (AFM). The surface properties of modified Ti 3 C 2 T x are characterized by zeta potential and water contact angle tests. The stability of Ti 3 C 2 T x -stabilized emulsions, and the structure of prepared ECPCs are systematically investigated. Findings: Surface modified Ti 3 C 2 T x flakes are used to stabilize water-in-oil (w/o) HIPEs for the first time. After the polymerization of continuous oil phase, ECPCs are successfully prepared with closed-cell porous structure. The pore size and size distribution of porous composites can be tailored by varying the content of Ti 3 C 2 T x flakes. The Ti 3 C 2 T x flakes are mainly immobilized at the water–oil interface and eventually form the segregated network in composites. Combining the unique segregated network and the outstanding metallic conductivity of Ti 3 C 2 T x , the prepared porous polymer composites exhibit good conductivity even with ultralow Ti 3 C 2 T x content of 0.016 vol%.

TiCN MXene hybrid BCN nanotubes with trace level Co as an efficient ORR electrocatalyst for Zn-air batteries

Yu Wang,Feng Gu,Lei Cao,Lanlan Fan,Tianjie Hou,Qian Zhu,Yu Wu,Shixian Xiong

Developing non-noble metal oxygen reduction reaction (ORR) electrocatalysts with high performance, excellent stability, and low-cost is crucial for the industrialization of fuel cells. Herein, trace level Co modified 3D hybrid titanium carbonitride MXene and boron-carbon-nitrogen nanotubes catalyst (TiCN–BCN–Co) is fabricated by spray-lyophilization and high-temperature pyrolysis . This strategy not only avoids the oxidation of Ti 3 C 2 T x MXene, but also introduces nitrogen atoms into the titanium carbide lattice to form a more electrocatalytically active TiCN crystal phase. The obtained TiCN–BCN–Co exhibits superior ORR catalytic activity with a positive half-wave potential of 0.83 V vs. RHE and outperforms commercial Pt/C in terms of stability and methanol tolerance. Impressively, the Zn-air battery with TiCN–BCN–Co cathode achieves a superior specific capacity of 791 mAh g −1 and long-term stability of 200 h.

Polyaniline/Small-Sized MXene/Carbon Cloth Electrodes with 3D Hierarchical Porous Structure for All-Solid-State Flexible Supercapacitors

Xiaotian Wu,Ganghong Zhang,Xing Zhao,Renpeng Liu,Zhengying Liu,Wei Yang,Mingbo Yang

The porous structure of electrodes can exert a significant impact on electrochemical performances of supercapacitors. Herein, the polyaniline/small-sized MXene/carbon cloth (PANI/S-MXene/CC) electrodes with 3D hierarchical porous structure are fabricated by a facile single-step pulsed electrodeposition. First, the PANI/S-MXene nanowires closely overlap each other and form a nanosized pore structure, which provides large specific surface area and abundant ion diffusion channels. Second, the CC with a large pore structure can facilitate permeation of gel electrolyte. S-MXene with small lateral size not only decreases charge transfer resistance of electrodes, but also ensures an interconnected porous framework. Consequently, the assembled all-solid-state flexible device delivers a high areal capacitance (478.4 mF cm −2 at 0.5 mA cm −2 ), a superior rate capability (307.5 mF cm −2 at 10 mA cm −2 ), a remarkable energy density (42.5 μWh cm −2 ), favorable cycle stability (75.4% capacitance retention after 4000 cycles), as well as 93.2% capacitance retention after 180° mechanical bending with 1000 cycles. Herein, it is revealed that size selection of nanomaterials is a priority when the porous structure is designed.

A bio-inspired MXene/quaternary chitosan membrane with a “brick-and-mortar” structure towards high-performance photothermal conversion

Yilin Wang,Bo Jiang,Tao Sun,Sha Wang,Yongcan Jin

MXenes (Ti3C2Tx) as two-dimensional nanomaterials have demonstrated great potential in energy storage, electromagnetic interference shielding and catalysis. However, the mechanical fragility of MXenes and their vulnerability to oxidation in a water–oxygen environment severely limit their practical application. Herein, inspired by the “brick and mortar” structure of natural nacre, a flexible MXene/quaternary chitosan (QCS) membrane with high mechanical robustness, outstanding antioxidant activity, and tailored electronic conductivity was developed for efficient photothermal conversion. The intercalation and confinement of positively charged QCS molecular chains between MXene nanosheets largely enhance the mechanical strength of MXene/QCS membranes by improving the interfacial interaction. Arising from the electrostatic interaction and hydrogen bonding between MXene nanosheets and QCS molecular chains, MXene/QCS membranes simultaneously possess a high tensile strength of 50.93 MPa and a Young's modulus of 4.4 GPa. The electronic conductivity can be easily tailored by controlling the MXene-QCS weight ratio, achieving a maximum value of 128 S m−1. Interestingly, the antioxidant nature of QCS contributes to an outstanding radical scavenging capacity of over 80%. More importantly, the developed MXene/QCS membrane demonstrates efficient photothermal conversion with the rate of the temperature increase up to 1.5 °C min−1 under simulated sunlight irradiation, showing great potential in the fields of photothermal therapy and solar steam generation.

Boosted CO2 photoreduction performance on Ru-Ti3CN MXene-TiO2 photocatalyst synthesized by non-HF Lewis acidic etching method

Qijun Tang,Peiyao Xiong,Haiqiang Wang,Zhongbiao Wu

Photocatalytic CO 2 reduction to produce value-added products is considered a promising solution to solve the global energy crisis and the greenhouse effect. In this study, Ti 3 CN MXene was synthesized using a Lewis acidic etching method without the usage of toxic hydrofluoric acid (HF). Ti 3 CN MXene was then used as a support for the in situ hydrothermal growth of TiO 2 and Ru nanoparticles. In the presence of 0.5 wt% Ru, Ru-Ti 3 CN-TiO 2 shows CO and CH 4 production rates of 99.58 and 8.97 μmol/g, respectively, in 5 h under Xenon lamp irradiation, more than 20.5 and 9.3 times that of commercial P25. The enhancement in photocatalytic activity was attributed to the synergy between the in-situ growth of TiO 2 on Ti 3 CN MXene and Ru nanoparticles. It was proven experimentally that Ti 3 CN MXene can provide abundant pathways for electron transfer. The separation and transfer of the photo-induced charge were further increased with the help of Ru and Ti 3 CN MXene, leaving more electrons to participate in the subsequent CO 2 reduction reaction. We believe that this work will encourage more attention to designing environment-friendly MXene-based photocatalysts for CO 2 photoreduction using the non-HF method.

Nb2CTx MXene Integrated Tapered Microfiber Based on Light-Controlled Light for Ultra-Sensitive and Wide-Range Hemoglobin Detection

Wenjie Li,Yinping Miao,Yibo Zheng,Kailiang Zhang,Jianquan Yao

Interlayer spacing enlarged 2D 1T-MoS2 and V2CTx MXene as superior anodes for boosting potassium-ion diffusion coefficient

Han Wang,Bingzhe Jia,Zhilin Zhao,Chunyan Luo,Xinming Wu

Two-dimensional (2D) materials used in potassium ion batteries (PIBs) have high theoretical capacitance and excellent rate characteristics. However, the origin of low diffusion of potassium ions and poor storage kinetics still remain challenge mainly due to the large size of potassium ions (0.138 nm) and narrow 2D interlayer spacing. Herein, the V 2 CT x -based hybrids including 1T-MoS 2 (1T -MoS 2 @V 2 CT x ) has been successfully constructed by the magneto-hydrothermal method and proved to be an eminent anode, which can make PIBs have high reversible capacity and eminent rate performance at the same time. Moreover, the combination of 2D 1T-MoS 2 and V 2 CT x not only significantly promotes the transfer of interfacial charges as well as accelerates the transmission and diffusion of electrons and K + , but also helps to alleviate the volume changes caused by the insertion/extraction of large-sized K + during the cycle, which makes the electrode exhibit good cycle stability. Density functional theory (DFT) indicates that the synergy effect between 1T-MoS 2 and V 2 CT x has significantly strengthened the potassium affinities and ion diffusion kinetics in the 1T-MoS 2 @V 2 CT x anode by reducing the ion diffusion energy barrier, thereby showing outstanding K + storage performance, especially in 1T-MoS 2 @V 2 CF 2 . As a result, the 1T-MoS 2 @V 2 CT x anode shows a high reversible capacity of 887.3 mA h g −1 at 0.1 A g −1 , eminent rate performance of the capacity maintaining 563.6 mA h g −1 at 2.0 A g −1 and remarkable cycle stability of 601.2/374.7 mA h g −1 with 69.4/56.5% capacity retention after 2000 cycles at 1.0/2.0 A g −1 . This work provides a new way for the exquisite design of 2D composite electrodes with excellent performance in PIBs.

Well-dispersed ultrafine Pt nanoparticles anchored on oxygen-rich surface of V2CTx (MXene) for boosting hydrogen evolution reaction

Jiapei Wang,Yunfeng Guan,Qin Zhang,Hui Zhu,Xuanke Li,Yanjun Li,Zhijun Dong,Guanming Yuan,Ye Cong

Developing homogeneous dispersion and efficient loading Pt-based electrocalalyst remains a huge challenge for hydrogen evolution reaction (HER). Herein, a facile approach to deposit Pt nanoparticles on two-dimensional V 2 C MXene (Pt/V 2 CT x ) is achieved. Pt nanoparticles with narrow size distribution (∼3 nm) and high loading capacity are uniformly anchored on the surface of V 2 CT x . The obtained catalysts possess outstanding activity and stability for HER. In 0.5 M H 2 SO 4 , the overpotential of Pt/V 2 CT x (20%) is 67 mV, and the Tafel slope is 20.6 mV/dec. The oxygen-rich surface of V 2 CT x can provide good hydrophilicity, low hydrogen adsorption free energy and oxophilicity to provide abundant bonding sites for Pt nanoparticles. Moreover, the intrinsically excellent conductivity of V 2 CT x and strong coupling between V 2 CT x and Pt are also of benefit for improving the charge transfer and accelerating the HER kinetics. Therefore, Pt/V 2 CT x may be a promising candidate for HER.

rGO/MXene sandwich-structured film at spunlace non-woven fabric substrate: Application to EMI shielding and electrical heating

Yu Zhang,Qiang Gao,Shuai Zhang,Xun Fan,Jianbin Qin,Xuetao Shi,Guangcheng Zhang

Combining flexible reduced graphene oxide (rGO) with highlyelectrical conductive and flame retardant MXene to prepare electromagnetic interference (EMI) shielding composite film is a research hotspot. In this work, with a small amount of polyvinyl alcohol (PVA) used as the adhesive, rGO/MXene loaded on spunlace non-woven fabric (SNF) through a soaking-drying-reduction method to form a sandwich structure composite film (SNF covered with rGO/MXene nanosheets as the interlayer, and rGO/MXene thin films as the upper and lower layers). The related EMI shielding effectiveness (SE), electric heating performance and flame retardancy of the fabricated sandwich structure composite film have been investigated. When the mass ratio of rGO to MXene is 6:4 (named rGO/MXene-4), the average SE T of the film can reach 55.81 dB in X-band with an absorption-dominant shielding. Applying a 4 V voltage to rGO/MXene-4 film, its surface temperature can exceed 110 °C within 10 s, which indicated the fabricated rGO/MXene-4 film can be applied as a high electromagnetic shielding electric heating device with outstanding flame retardancy.