We show that in contrast to conventional compound photocatalysts, α-sulfur crystals of cyclooctasulfur (S ₈) are a visible-light-active elemental photocatalyst. The α-S crystals were found to have the ability not only to generate ·OH radicals but also to split water in a photoelectrochemical process under both UV-vis and visible-light irradiation. Although the absolute activity obtained was low because of the large particle size and poor hydrophilicity of the α-S crystals studied, there is great potential for increasing the activity with the assistance of known strategies such as surface modification, nanoscaling, doping, and coupling with other photocatalysts.

Gang Liu;Ping Niu;Lichang Yin;会明 成

Journal of the American Chemical Society

2012-6-6

In this work, a photothermal-resistance technique is developed to characterize the thermophysical properties of one-dimensional micronanostructures. In this technique, a periodically modulated laser beam is used to achieve noncontact heating of suspended individual wires. The temperature response of the sample is monitored by measuring its electrical resistance variation. A 25.4 μm thick platinum wire is used as the reference sample to verify the technique. Applying the photothermal-resistance technique, the thermal diffusivity of single-wall carbon nanotube bundles is measured. The measured thermal diffusivities for three different single-wall carbon nanotube bundles are 2.98× 10-5, 4.41× 10-5, and 6.64× 10-5 m2 s, respectively. These values are much less than the thermal diffusivity of graphite.

J. Hou;X. Wang;C. Liu;会明 成

Applied Physics Letters

2006-5-1

Graphene and graphene oxide (GO), as wonder materials, have penetrated nearly every field of research. One of their most attractive features is the functionality and assembly of graphene or GO, in which they can be considered to be chemically functionalized building blocks for creating unconventional porous graphene materials (PGMs) that not only combine the merits of both porous materials and graphene, but also have major advantages over other porous carbons for specific applications. The chemistry and approaches for functionalizing graphene and GO are first introduced, and typical procedures for pore creation (e.g., in-plane pores, 2D laminar pores, and 3D interconnected pore assemblies), self-assembly, and tailoring mechanisms for PGMs to highlight the significance of precise control over the pore morphology and pore size are summarized. Because of their unique pore structures, with different morphologies and intriguing properties, PGMs serve as key components in a variety of applications such as energy storage, electrocatalysis, and molecular separation. Finally, the challenges relating to PGMs from the understanding of chemical self-assembly to specific applications are discussed, and promising solutions on how to tackle them are presented. This provides an insightful outlook for the future development of the chemistry and applications of PGMs.

Haibo Huang;Haodong Shi;Pratteek Das;Jieqiong Qin;Yaguang Li;Xiao Wang;Feng Su;Pengchao Wen;Suyuan Li;Pengfei Lu;Fangyan Liu;Yuejiao Li;Ying Zhang;Yi Wang;Zhong Shuai Wu;会明 成

Advanced Functional Materials

2020-10-1

To achieve the long-term oxidation protection of carbon/carbon composites at low and medium temperatures, a SiC/B₄C-B₂O₃-SiO₂-Al₂O₃ coating was applied on the composites. The coating exhibits a dual-layer structure with a dense SiC inner layer and B₄C-B₂O₃-SiO₂-Al₂O₃ multi-phase outer layer. The effects of Al₂O₃ contents and oxidation temperatures on the oxidation behavior of the coated C/C were investigated. The results shows that the coating with 7.7wt.% Al₂O₃ performs excellent self-healing ability and can protect the C/C composites with weight losses of less than 1% for 250h at 800°C and for 90h at 900°C and 1000°C.

Chenglong Hu;Shengyang Pang;Sufang Tang;Zhi Yang;Shijun Wang;会明 成

Corrosion Science

2015-5-1

Potassium-ion batteries are a compelling technology for large scale energy storage due to their low-cost and good rate performance. However, the development of potassium-ion batteries remains in its infancy, mainly hindered by the lack of suitable cathode materials. Here we show that a previously known frustrated magnet, KFeC₂O₄F, could serve as a stable cathode for potassium ion storage, delivering a discharge capacity of ~112 mAh g⁻¹ at 0.2 A g⁻¹ and 94% capacity retention after 2000 cycles. The unprecedented cycling stability is attributed to the rigid framework and the presence of three channels that allow for minimized volume fluctuation when Fe²⁺/Fe³⁺ redox reaction occurs. Further, pairing this KFeC₂O₄F cathode with a soft carbon anode yields a potassium-ion full cell with an energy density of ~235 Wh kg⁻¹, impressive rate performance and negligible capacity decay within 200 cycles. This work sheds light on the development of low-cost and high-performance K-based energy storage devices.

Bifa Ji;Wenjiao Yao;Yongping Zheng;Pinit Kidkhunthod;Xiaolong Zhou;Sarayut Tunmee;Suchinda Sattayaporn;会明 成;Haiyan He;Yongbing Tang

Nature Communications

2020-12-1

With an aim to enhance the photocatalytic activity, Pt loaded TiO₂–Al-MCM-41 catalysts with high surface area were synthesized by a multistep route. The waste of the rice processing, rice husk (RH), was used as the precursor for the extraction of silica. The diffuse reflectance and photoluminescence spectroscopy revealed the extension of the absorption edge in the visible region and exciton trapping nature of the dispersed platinum. The structural analysis was carried out by XRD, whereas X-ray photoelectron spectroscopy identified the chemical states of the components of the synthesized powders. The BET surface area measurements revealed the reduction in the surface area and pore volume with the increasing platinum loading. TEM micrographs showed the uniform distribution of TiO₂ and Pt nanoparticles at the surface of Al-MCM-41. The photocatalytic efficiency of the synthesized powders as photocatalysts was obtained for the removal of 100 ppm CN⁻ from aqueous solution in fluorescent blue light exposure. Compared to unsupported TiO₂, the Pt-loaded catalysts exhibited substantially high activity for the removal of CN⁻. A plausible mechanism for the removal of cyanide ions was proposed. The catalysts showed excellent stability and reproducibility in the successive use.

Mohammad W. Kadi;A. Hameed;R. M. Mohamed;Iqbal M.I. Ismail;Yaser Alangari;会明 成

Arabian Journal of Chemistry

2019-11

(Graph Presented) Hydrogen energy systems: For reversible hydrogen storage TiF₃ is superior to TiCl₃ as a dopant precursor for preparing catalytically enhanced Ti-NaAlH₄ systems (see diagram). In addition to the increased hydrogen capacity, the TiF₃-doped NaAlH₄ exhibits a more pronounced kinetic enhancement than the TiCl₃-doped hydride at varied operational conditions.

Ping Wang;Xiang Dong Kang;会明 成

ChemPhysChem

2005-12

Nanocrystalline Zr-based hydrogen storage alloys were produced by completely crystallizing the melt-spun amorphous precursor Zr0.9Ti0.i(NiVMnCo)2.1 alloy. The cycle stability of nanocrystalline hydrogen storage alloy is obviously better than that of conventional cast alloy at 1C 100% DOD condition. The cycle life of 40 m/s melt-spun alloy electrode after annealing is very long, the capacity keeping-rate is about 70% after 1350 cycles. The cycle life model of calculating Zr-based hydrogen alloy electrode was first established, the calculation data were almost identical with the test results.

Chen Lian;Wu Feng;Tong Min;Chen Dong;Chen Demin;会明 成;Wen Mingfen

Xiyou Jinshu Cailiao Yu Gongcheng/Rare Metal Materials and Engineering

2001

The high-efficiency photocarrier collection at the interfaces plays an important role in improving the performance of perovskite solar cells (PSCs) because the photocarrier effective diffusion lengths in the lead halide perovskite absorbers usually surpass the incident depths of light. Developing the electron selective layer (ESL) that has good interfaces with photoactive perovskite and current collector layer-like fluorine-doped tin oxide (FTO) is actively pursued. Here, an unusual dense film of faceted rutile TiO₂ single crystals with a gradient of the Sn⁴⁺ dopant grown heteroepitaxially on the FTO layer is obtained by a hydrothermal route and subsequent thermal treatment. Owing to the global features including low concentration of defects, atomically smooth coherent interface with FTO, and gradient doping-induced built-in electric field to promote the collection of photoelectrons in it, an optimal PSC with such a film as the ESL exhibits an efficiency of 17.2% with an open-circuit voltage of 1.1 V and fill factor of 76.1%, which are among the highest values of the PSCs with rutile TiO₂ films as ESLs.

Tingting Wu;Chao Zhen;Huaze Zhu;Jinbo Wu;Chunxu Jia;Lianzhou Wang;Gang Liu;Nam Gyu Park;会明 成

ACS applied materials & interfaces

2019

The oxidation behaviors in stationary air of C/C-SiC gradient matrix composites and C/C composites were compared with each other. The results show that the oxidation threshold of C-SiC materials increases with the amount of SiC particles in the codeposition matrix. The oxidation rate of C/C-SiC gradient matrix composites is significantly lower than that of C/C material. The micro-oxidation process was observed by SEM.

Jingyi Deng;Wenchuan Liu;Haifeng Du;会明 成;Yiyi Li

Journal of Materials Science and Technology

2001-9