查找使用阿拉丁产品的科研文献

Nickel nanoparticles encapsulated inside mesoporous MoO2 for industrially stable anion-exchange membrane water electrolysis

Li Zhiheng,Lin Gaoxin,Wang Linqin,Wu Wen,Ding Yunxuan,Sun Licheng

The hydrogen evolution reaction (HER) plays a vital role in the production of green hydrogen, but it still faces practical issues, including low cost-efficiency, reduced catalytic activity and limited lifetime under industry-required ampere-scale current densities. Here we report a heterogeneous nucleation strategy to produce a scaled-up, inexpensive, energy-efficient and highly stable NiMo-based electrode (that is, h-Ni/MoO 2 ) for HER electrolysis. The abundant inner surface formed by H 2 O release during annealing favours an encapsulated structure of the h-Ni/MoO 2 catalyst, that is, Ni nanoparticles in porous MoO 2 matrix, which ensures high HER activity (low overpotential of 70.9 ± 4.5 mV) and high HER stability (over 25,000 h) in 1 M KOH at −1,000 mA cm −2 . When using h-Ni/MoO 2 as the cathode catalyst, practical anion-exchange membrane water electrolysis delivers high activity (for example, 5.6 A cm −2 at 1.8 V and 10.2 A cm −2 at 2.0 V) and high durability (for example, over 2,000 h at 1,000 mA cm −2 ).

Aspect Ratio Design and Heterostructure Construction of MoO2/NC Nanorods for Broadband Microwave Absorption

Yidan He,Yunliang Dai,Yuke Zheng,Xiaojuan Zhang

The exploration of high-performance wave absorbing materials is particularly critical for solving electromagnetic pollution. Based on the designability and structural virtue of one-dimensional anisotropic structure, a succession of MoO2/N-doped carbon (MoO2/NC) heterogeneous nanorods with various aspect ratios have been synthesized by hydrothermal, chemical oxidation polymerization and calcination process. To investigate the effect of aspect ratio on the microwave attenuation capacity, these fabricated nanorods are compounded with polyvinylidene fluoride (PVDF) under different filler contents. It is concluded that the aspect ratio can effectively regulate the microwave absorption performance. Specifically, the MoO2/NC-1/PVDF composites acquire the RLmin value of −56.9 dB at 2.9 mm and the RLmin value (−44.2 dB) of MoO2/NC-2/PVDF composites appear at a thinner thickness of 1.8 mm under a filler loading of 15 wt%. With the increment of aspect ratio, the optimal effective absorption bandwidth (EAB) of MoO2/NC-3/PVDF composites extend up to 6.32 GHz at 2.0 mm within a filler content of only 10 wt%, covering the whole Ku band. Meanwhile, the radar cross section simulations of MoO2/NC/PVDF composites further verify their immense potential in practical application. This work demonstrates that the aspect ratio design is conducive to acquisition for regulable and broadband microwave absorption under low filler loading.

Construction of one-dimensional hierarchical MoO2/C with dominant dielectric loss for microwave absorption

Rong Qiang,Yuancheng Ding,Yulong Shao,Lei Rong,De Zhang,Rui Hao,Rui Xue,Na Xiao,Hongchen Liu,Jiawen Qiu

Driven by the rapid advancement of electronic devices and wireless communication technologies, there is an urgent demand for high-performance microwave absorbing materials. In this work, one-dimensional MoO 2 /C composites were synthesized through an in-situ polymerization-pyrolysis strategy. By precisely tuning the pyrolysis temperature, remarkable microwave absorption performance was achieved. The resulting material exhibits a minimum reflection loss of −59.1 dB at a matching thickness of 1.7 mm and delivers an effective absorption bandwidth of 5.6 GHz at 2.0 mm. Furthermore, it demonstrates a radar cross-section of 27.08 dB·m² at a 0° scattering angle. Comprehensive experimental and theoretical analyses reveal that the enhanced electromagnetic wave attenuation is primarily attributed to one-dimensional interfacial polarization at the interfaces between MoO 2 nanorods and porous carbon layers, as well as efficient axial electron transport pathways. This work presented a viable strategy for the preparation of one-dimensional MoO 2 -based dielectric microwave absorption materials.

Descriptor-guided Fe/V co-doped hollow MoO2 nanostructures for photo-assisted water splitting

Zi-Ang Lu,Shan Jin,Tingting Qu,Ranran Liang,Yunchen Du,Mengxin Chen,Ping Xu

Conductive oxides with chemically distinct local environments are attractive for bifunctional water splitting because hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) impose different requirements on adsorption and charge transfer. Here, a descriptor-informed Fe/V co-doping strategy is proposed to regulate MoO 2 for photo-assisted electrocatalysis. Density functional theory (DFT) screening based on incorporation thermodynamics, local M–O bond mismatch, and near-Fermi-level electronic states identifies V as the most favorable dopant for lattice incorporation and Fe as the dopant that minimizes local bond-length mismatch while strongly perturbing the electronic structure. Guided by this complementarity, Mo 0.9 Fe 0.05 V 0.05 O 2 was synthesized and compared with pristine MoO 2 and single-doped controls. The co-doped catalyst preserves the MoO 2 framework and delivers the best overall performance, requiring 166 and 243 mV for HER and 253 and 281 mV for OER to reach 10 and 50 mA cm −2 under illumination. Electrochemical measurements reveal improved charge-transfer behavior and enhanced light-induced current response. Optical characterization and Finite-difference time-domain (FDTD) simulations indicate that the hollow architecture promotes optical-field localization, while DFT reaction energetics suggest site-dependent catalytic preferences, with V-associated environments favoring hydrogen adsorption and Fe-associated environments facilitating OER intermediate conversion. This study demonstrates that pairing dopants according to lattice compatibility and electronic perturbation is an effective route to activate MoO 2 for photo-assisted bifunctional water splitting. A descriptor-guided Fe/V co-doping strategy activates hollow MoO 2 for photo-assisted water splitting. Fe/V co-doping enables complementary HER/OER active sites, while the hollow architecture promotes optical-field localization and enhances interfacial charge-transfer kinetics under illumination. Download: Download high-res image (143KB) Download: Download full-size image

Cu-mediated proximal electronic engineering in Ni/MoO2 heterostructures for industrial alkaline hydrogen evolution

Lisong Zhong,Ying Li,Lirong Zheng,Jian Sun,Zhaohui Jin,Linqi Shi,Pengcheng Zhao,Baoyu Qi,Liu Yang,Zhongwei Chen

The development of highly active and robust non-noble-metal catalysts for alkaline hydrogen evolution reaction (HER) is imperative for industrial anion exchange membrane water electrolysis (AEMWE). Herein, we construct a hierarchically multiphase heterostructure via a customized reduction strategy, featuring uniformly dispersed Cu and Ni metallic phases anchored onto a conductive isolated MoO 2 substrate (Cu/Ni@MoO 2 ). The catalyst achieves an ultralow overpotential of 140.7 mV at 1 A cm −2 in 1 M KOH, coupled with ampere-level operational stability exceeding 2000 h without degradation. In-situ Raman spectroscopy and theoretical analyses unveil that Cu-mediated interfacial engineering dynamically restructures interfacial water networks, reduces the water dissociation barrier and optimizes hydrogen adsorption energy. Impressively, the AEMWE device equipped with a Cu/Ni@MoO 2 cathode achieves the industrial-relevant current densities 1.74 A cm −2 and 3.61 A cm −2 at the voltages of only 1.8 V and 2 V (60 °C), respectively, while demonstrating exceptional durability with negligible voltage decay throughout 1000 h operation at 0.5 A cm −2 . This work presents a novel design strategy for high-current-density electrocatalysts, bridging atomic-scale insights and industrial hydrogen production requirements.

Oriented lateral growth of monolayer MoS2 mediated by highly-oriented MoO2 nanorods on sapphire

Jie Wang,Feifei Lan,Zeyan Wang,Yingmin Wang,Baibiao Huang,Yujian Wang

Two-dimensional (2D) transition metal chalcogenides (TMDs) have demonstrated immense potential and broad prospects in advancing the fields of next-generation optoelectronics, spintronics, valley electronics, and traditional electronics. In recent years, significant progress has been made in the growth research of TMDs through continuous optimization and innovation of various synthetic strategies. However, precisely controlling the growth conditions of materials, synthesizing high-quality 2D materials with a single domain structure, and achieving the desired shape and performance standards remain complex scientific challenges. Here, we report on the study of MoS2 nucleation and growth habits by precisely controlling the ratio of molybdenum and sulfur sources during the growth process. Using pre-deposited highly oriented MoO2 nanorods as templates, two preferentially oriented (0° or 60°) MoS2 crystal domains were obtained on c-plane sapphire. Characterization using Raman spectroscopy, PL, XPS, and HRTEM reveals that the monolayer MoS2 continuous film, grown using this templating method, possesses superior quality. Our work demonstrates a method for directional growth of 2D MoS2 thin films using highly oriented 1D MoO2 nanorods as templates and precursors, providing new insights into orientation control for epitaxial growth of 2D TMD materials.

Tri-functionalized polypropylene separator by rGO/MoO2 composite for high-performance lithium–sulfur batteries

Xu Kun,Liang Xin,Wang Lu-Lu,Wang Yong,Yun Ju-Feng,Sun Yi,Xiang Hong-Fa

Abstract The popularity of lithium–sulfur batteries has been increasing gradually due to their ultrahigh theoretical specific capacity and energy density. Nevertheless, they also have lots of drawbacks to be overcome, such as poor conductivity, severe volume expansion, and serious “shuttle effect”. In this work, reduced graphene oxide/molybdenum dioxide (rGO/MoO 2 ) composite is synthesized and applied to modify polypropylene separator. The modified polypropylene separator introduces synergistic tri-functions of physical adsorption, chemical interaction and catalytic effects, which can inhibit the “shuttle effect” and enhance the electrochemical performances of lithium-sulfur batteries. In the prepared rGO/MoO 2 composite, the polar MoO 2 chemically adsorbs the intermediate lithium polysulfide, while the rGO with good electrical conductivity not only acts as a physical barrier to prevent diffusion of polysulfide ions, but also improves the conversion efficiency of active material intercepted on the separator. As a consequence, the battery assembled with rGO/MoO 2 modified polypropylene separator exhibits a reversible capacity of 757.5 mAh·g −1 after 200 cycles at 0.2C with a negligible capacity decay of 0.207% per cycle, which indicates a good long-period cycling stability. Furthermore, the rate performance and self-discharge suppression are also improved by introducing modified polypropylene separator. It shows that rGO/MoO 2 composite is a promising material for separator modification in lithium-sulfur batteries. Graphic abstract

Porous NiMoO4−x/MoO2 hybrids as highly effective electrocatalysts for the water splitting reaction

Zhe Zhang,Xingxing Ma,Jilin Tang

The rational design of an optimal bifunctional electrocatalyst for water splitting with low cost and high activity is greatly desired for the realization of efficient conversion and storage of sustainable energy. Herein, a novel NiMoO4−x/MoO2 hybrid electrocatalyst with atomic-level coupled nanointerfaces and plentiful Mo5+ species is reported. The NiMoO4−x/MoO2 electrocatalyst shows excellent electrocatalytic performances for both the HER and the OER in alkaline media with Tafel slopes of 31 and 69 mV dec−1, and a current density of 10 mA cm−2 at overpotentials of 41 and 233 mV for the HER and OER, respectively. The NiMoO4−x/MoO2 can further work as bifunctional electrode materials for overall water splitting and achieves a current density of 10 mA cm−2 at a voltage of only 1.56 V.

Enhanced kinetic behaviors of hollow MoO2/MoS2 nanospheres for sodium-ion-based energy storage

Jinyang Wu,Mingjun Jing,Tianjing Wu,Mingguang Yi,Yansong Bai,Wenhui Deng,Yirong Zhu,Yingchang Yang,Xianyou Wang

Mo-based heterostructures offer a new strategy to improve the electronics/ion transport and diffusion kinetics of the anode materials for sodium-ion batteries (SIBs). MoO 2 /MoS 2 hollow nanospheres have been successfully designed via in-situ ion exchange technology with the spherical coordination compound Mo-glycerates (MoG). The structural evolution processes of pure MoO 2 , MoO 2 /MoS 2 , and pure MoS 2 materials have been investigated, illustrating that the structure   of   the   nanosphere   can be maintained by introducing the S-Mo-S bond. Based on the high conductivity of MoO 2 , the layered structure of MoS 2 and the synergistic effect between components, as-obtained MoO 2 /MoS 2 hollow nanospheres display enhanced electrochemical kinetic behaviors for SIBs. The MoO 2 /MoS 2 hollow nanospheres achieve a rate performance with 72% capacity retention at a current of 3200 mA g −1 compared to 100 mA g −1 . The capacity can be restored to the initial capacity after a current returns to 100 mA g −1 , while the capacity fading of pure MoS 2 is up to 24%. Moreover, the MoO 2 /MoS 2 hollow nanospheres also exhibit cycling stability, maintaining a stable capacity of 455.4 mAh g −1 after 100 cycles at a current of 100 mA g −1 . In this work, the design strategy for the hollow composite structure provides insight into the preparation of energy storage materials.

A novel dopamine sensor based on Mo doped reduced graphene oxide/polyimide composite membrane

Lingpu Jia,Yaxin Zhou,Yimin Jiang,Aihua Zhang,Xin Li,Chunming Wang

A novel Mo doped reduced graphene oxide/polyimide (Mo-rGO/PI) composite membrane sensor for dopamine (DA) has been successfully prepared by a simple and effective method. In this work, the rGO was doped into PI to prepare polymer composite membrane . Although rGO has a certain degree of catalytic activity for DA, more important is Mo doped rGO/PI film can enhance its electrocatalytic activity towards the oxidation of DA, and so far there is almost no report that MoO 2 can catalyze DA. In order to find the best film, different doped ratios of Mo powder are further investigated, and the combined characterization by X-ray photoelectron spectra and energy-dispersive X-ray spectroscopy indicate that Mo exist in rGO/PI film in the form of MoO 2 . Under optimal conditions, the Mo doped rGO/PI film exhibits excellent catalytic activity to DA, with a linear response throughout the concentration range from 0.1 to 2000 μM, it also shows long-term stability and good reproducibility, and performs well for detection of DA in human blood serums and injection. These results suggest that the novel Mo-rGO/PI film is a promising candidate for the accurate and reliable detection of DA signals in biological samples.

MoO2 Sacrificial Layer for Optimizing Back Contact Interface of Cu2ZnSn(S,Se)4 Solar Cells

Bin Xu,Xiaoshuang Lu,Chuanhe Ma,Yulin Liu,Ruijuan Qi,Rong Huang,Ye Chen,Pingxiong Yang,Junhao Chu,Lin Sun

Three-dimensional MoO2 nanotextiles assembled from elongated nanowires as advanced anode for Li ion batteries

Guoqing Xu,Ping Liu,Yurong Ren,Xiaobing Huang,Zhiguang Peng,Yougen Tang,Haiyan Wang

The fabrication of an ideal electrode architecture consisting of robust three dimensional (3D) nanowire networks have gained special interest for energy storage applications owing to the integrated advantages of nanostructures and microstructures. In this work, 3D MoO 2 nanotextiles assembled from highly interconnected elongated nanowires are successfully prepared by a facile stirring assisted hydrothermal method and followed by an annealing process . In addition, a methylbenzene/water biphasic reaction system is involved in the hydrothermal process. When used as an anode material in Li ion batteries (LIBs), this robust MoO 2 nanotextiles exhibit a high reversible capacity (860.4 mAh g −1 at 300 mA g −1 ), excellent cycling performance (89% capacity retention after 160 cycles) and rate capability (577 mAh g −1  at 2000 mA g −1 ). Various synthetic factors to the fabrication of 3D nanotextiles structure are discussed here and this design of 3D network structures may be extended to the preparation of other functional nanomaterials .