A photoelectrode of single-crystal rutile TiO ₂ pillars with well-developed facets shows a 2.5 times higher capability of water splitting at 0.3 V than a conventional anatase TiO ₂ nanotube array electrode. The improvement is attributed to the synergistic effects of the high crystallinity of single-crystal rutile pillars, the exposed high-energy {011} and {111} as the reactive facets of water oxidation reaction and the extended light absorption range by ca. 23 nm.

Chao Zhen;Gang Liu;会明 成

Nanoscale

2012-7-7

MgH₂ + TiF₃ system was mechanically prepared and investigated with regard to hydrogen absorption/desorption performance. It was found that the sorption kinetics of MgH₂ can be markedly improved by mechanical milling with 4 mol% TiF₃, in particular at reduced operation temperatures. Even at a moderate temperature range (313-373 K), the hydrogen absorption can be largely completed within about 25 s. On the desorption aspect, the catalytic enhancement arising upon adding TiF₃ allows the sample to desorb near 5 wt.% hydrogen within 600 s at 573 K. Furthermore, such enhancement in kinetics was observed to persist in the absorption/desorption cycles. Preliminary XRD examination was also performed to understand the observed catalytic effect of TiF₃ additive.

Lai Peng Ma;Ping Wang;会明 成

Journal of Alloys and Compounds

2007-4-25

In an early stage of the decade, most of works on carbon nanotubes were centred on chemistry and physics. Due to extraordinary mechanical and thermal properties, these nanotubes have been used as nano-fibres for the improvement of the global mechanical properties of advanced composite structures. This paper reports the micro-hardness and flexural properties of nanotube/epoxy composites with different amounts of nanotubes content. Experimental measurements and microscopic observations of the composites pre-treated at different temperatures are discussed in detail. The results show that the hardness of the nanotube composites varied with different nanotube weight fractions. The flexural strength decreased by 10% for a composite beam with 2 wt.% of nanotubes. The fracture surfaces of nanotube composite were perpendicular to the nanotube pre-treated at 70 °C, and parallel to nanotubes pre-treated at -180 °C. The SEM images also revealed that all nanotubes were completely pulled out after the flexural strength test due to a weak-bonding strength between the nanotube and matrix.

Kin Tak Lau;San Qiang Shi;会明 成

Composites Science and Technology

2003-6

The Li-Mg-N-H system was prepared by reacting magnesium amide [Mg(NH ₂)₂] with lithium nitride (Li₃N) and investigated with regard to the hydrogen storage properties. Our study shows that the present method is superior to the conventional route in enhancing the reversible dehydrogenation properties. Through optimizing the Li ₃N:Mg(NH₂)₂ ratio in the starting materials, the reversible capacity of Li-Mg-N-H system increases to 4.9 wt %, 18% higher than that typically obtained from the Mg(NH₂)₂ + 2LiH mixture at 200 °C. Furthermore, increasing the Li₃N:Mg(NH ₂)₂ ratio is effective for mitigating the ammonia release from thus-prepared samples. Combined property/structure investigations indicate that the obtained enhancements should be ascribed to the effects of LiNH2 and LiH that were in situ generated from the excess Li₃N. LiNH ₂ may promote the dehydrogenation reaction via seeding the reaction intermediate. The concurrently generated LiH acts as an effective ammonia trapping agent. These findings highlight the potential of "intermediate seeding" as a strategy to enhance the reversible hydrogen storage properties of metal-N-H systems.

Lai Peng Ma;Hong Bin Dai;Zhan Zhao Fang;Xiang Dong Kang;Yan Liang;Pei Jun Wang;Ping Wang;会明 成

Journal of Physical Chemistry C

2009-6-4

2D materials have a range of unique properties and are promising building blocks for the fabrication of macroscopic materials for many applications ranging from flexible electronics to energy storage devices. The development of effective methods to fabricate 2D material-based macroscopic materials with designed structures is the key to enabling high performance. Lately, 3D printing has emerged as a new technique to assemble such materials. Compared to conventional fabrication methods, 3D printing techniques have a high degree of customization of the structure with a broad range of domain sizes from nanometers to centimeters, and thereby give the resulting products additional structure-related functionalities. Recent advances in the fabrication of 2D material-based macrostructures using 3D printing techniques and their uses in different fields are reviewed. Challenges and opportunities for the future development of the topic are also discussed.

Rui Yang;Jingzhuo Zhou;Chuang Yang;Ling Qiu;会明 成

Advanced Materials Technologies

2020-9-1

The state-of-art and key problems of carbon nanotube (CNT) based polymer composites (CNT/polymer composites) including CNT/polymer structural composites and CNT/polymer functional composites are reviewed. Based on the results reported up to now, CNTs can be an effective reinforcement for polymer matrices, and the tensile strength and elastic modulus of CNT/polymer composites can reach as high as 3600 MPa and 80 GPa, respectively. CNT/polymer composites are also promising functional composite materials with improved electrical and thermal conductivity, etc. Due to their multi-functional properties, CNT/polymer composites are expected to be used as low weight structural materials, optical devices, thermal interface materials, electric components, electromagnetic absorption materials, etc. However, the full potential of CNT/polymer composites still remains to be realized. A few key problems, such as how to prepare structurecontrollable CNTs with high purity and consistently dependable high performance, how to break up entangled or bundled CNTs and then uniformly disperse and align them within a polymer matrix, how to improve the load transfer from matrix to CNT reinforcement, etc, still exist and need to be solved in order to realize the wide applications of these advanced composites.

J. H. Du;J. Bai;会明 成

Express Polymer Letters

2007-5

Design and fabrication of flexible Li-ion batteries (FLIBs) with excellent electrochemical and structural stability via scalable fabrication techniques are important for their practical applications. A wide range of FLIBs with excellent flexibility have been reported. However, sophisticated designs and complex fabrication techniques are often used in fabricating FLIBS, making them difficult to be realized in industrial production. Here, we fabricate FLIBs with an integrated structure by assembling the LiFePO₄ cathode, Li₄Ti₅O₁₂ anode, graphene current collectors, and poly(vinylidene fluoride) (PVDF) electrolyte all together on commercial printing paper via conventional and scalable Meyer rod coating. In the design, the commercial paper serves as a flexible substrate to enable good flexibility of the device, and the paper is coated twice with PVDF to avoid the short-circuit problem and create a strong binding to integrate the device. The resultant integrated FLIBs exhibit excellent internal structural stability and good electrochemical performance under cycling bending for 100 times.

Linchao Zeng;Shaohua Chen;Minsu Liu;会明 成;Ling Qiu

ACS applied materials & interfaces

2019-12-18

Monolayer transition metal dichalcogenides are 2D materials with many potential applications. Chemical vapor deposition (CVD) is a promising method to synthesize these materials. However, CVD-grown materials generally have poorer quality than mechanically exfoliated ones and contain more defects due to the difficulties in controlling precursors' distribution and concentration during growth where solid precursors are used. Here, thiol is proposed to be used as a liquid precursor for CVD growth of high quality and uniform 2D MoS₂. Atomic-resolved structure characterizations indicate that the concentration of sulfur vacancies in the MoS₂ grown from thiol is the lowest among all reported CVD samples. Low temperature spectroscopic characterization further reveals the ultrahigh optical quality of the grown MoS₂. Density functional theory simulations indicate that thiol molecules could interact with sulfur vacancies in MoS₂ and repair these defects during the growth of MoS₂, resulting in high-quality MoS₂. This work provides a facile and controllable method for the growth of high-quality 2D materials with ultralow sulfur vacancies and high optical quality, which will benefit their optoelectronic applications.

Simin Feng;Junyang Tan;Shilong Zhao;Shuqing Zhang;Usman Khan;Lei Tang;Xiaolong Zou;Junhao Lin;会明 成;Bilu Liu

Small

2020-9-1

W. G. Zhang;会明 成;T. S. Xie;Z. H. Shen;B. L. Zhou;H. Q. Ye

Carbon

1997

Identification of effective catalyst is a subject of great interest in developing MgH₂ system as a potential hydrogen storage medium. In this work, the effects of typical titanium compounds (TiF₃, TiCl₃, TiO₂, TiN and TiH₂) on MgH₂ were systematically investigated with regard to hydrogen sorption kinetics. Among them, adding TiF₃ leads to the most pronounced improvement on both absorption and desorption rates. Comparative studies indicate that the TiH₂ and MgF₂ phases in situ introduced by TiF₃ fail to explain the superior catalytic activity. However, a positive interaction between TiH₂ and MgF₂ is observed. Detailed comparison between the effect of TiF₃ and TiCl₃ additive suggests the catalytic role of F anion. XPS examination reveals that new bonding state(s) of F anion is formed in the MgH₂ + TiF₃ system. On the basis of these results, we propose that the substantial participation of F anion in the catalytic function contributes to the superior activity of TiF₃.

Lai Peng Ma;Ping Wang;会明 成

International Journal of Hydrogen Energy

2010-4