JOURNAL OF PHYSICS D-APPLIED PHYSICS
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2021
·Vol. 54
·期 40
·405101
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IF 3.207
Wei-song Liu,Hui Yang,Lan Li
The heterostructure device based on polyvinylidene fluoride (PVDF)/MoS2 films was succesfully prepared and showed a good hysteresis feature with a unique resistive switching perpromance, where the logarithmic I–V curve looks like a butterfly. The on-off ratio for the resistive switching in the device based on PVDF/MoS2 films reaches 2.5 × 102 and the resistive switching happens at −0.9 V and −4.9 V for a half loop. The influence of the introduction of MoS2 and ferroelectric PVDF film was also studied and compared to a device based on a single film. The underlying physical mechanism for the unique resistive transition was attributed to the polarization field from the ferroelectric polymer PVDF and the S vacancies in MoS2.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2024
·
IF 8.1
Guoqiang Zhang,Jianqing Li,Zhiqi Wang,Xi Xu,Tao He,Jingli Wu,Jinhu Wu
The cocatalysts play a key role in photocatalytic technology in remarkably improving the efficiency of H 2 evolution. Herein, S vacancies-rich Cd 0.6 Zn 0.4 S nanorods (CZS NRs) were prepared via solvothermal method. Then, as-obtained CZS NRs were modified with Ni–Co PBA-derived NiS x nanoparticles (NPs) cocatalyst using grinding method. The optimized CZS/NiS x -N-1.5 hybrids (CZS/NiS x -N, where N represents nickel nitrate which was used as nickel source) exhibited outstanding stability and activity, the average rate of H 2 was up to 192.82 mmolg −1 h −1 in deionized water medium, which was 201.4% higher than that of CZS. Besides, NiS x -A and NiS x -C cocatalysts with different particle sizes were obtained using nickel acetate (A) and nickel chloride (C) as nickel source, respectively. The CZS/NiS x -C-1.5 and CZS/NiS x -A-1.5 exhibited the H 2 evolution rate of 180.70 and 201.93 mmolg −1 h −1 in deionized water medium, respectively. The as-prepared materials also exhibited the excellent H 2 evolution performance in natural seawater medium. Besides, the photocatalytic mechanism of H 2 evolution over CZS NRs/NiSs NPs was also discussed. This work develops a novel H 2 evolution cocatalyst and unveils the relationship between the loading amount/particle size of cocatalyst on the H 2 evolution rate.
研究领域:
材料科学
·
能源科学
✓ 已验证
DOI
高影响因子
FUEL
·
2024
·
IF 6.7
Man Lang,Dengwei Wang,Shenbo Yang,Hao Li
The development of excellent performance catalysts for the hydrodeoxygenation of renewable biomass into value-added chemicals is essential but remains extremely challenging. Herein, a series of novel metal-free carbo-catalyst catalysts through one-step-pyrolysis strategy were fabricated for the hydrodeoxygenation (HDO) of lignin-derived vanillin (VAN) to produce 2-methoxy-4-methylphenol (MMP). It has been demonstrated that 81.32 % VAN conversion could be acquired with a high selectivity of 77.30 % of MMP under the condition of 240 °C, 1 MPa H 2 and 4 h with the assistance of the optimized NSCC-800-7 catalyst. After characterization of the catalyst and density functional theory (DFT) calculations, the outstanding catalytic activity is attributed to the synergistic effect between nitrogen and sulfur dopants, which effectively regulates the number of active sites. N-S vacancy (NSVs) in the N-doped carbon catalysts is found to play an active site for the VAN HDO reaction, which is greatly beneficial to activating hydrogen molecules. Meanwhile, sulfur doping can promote the formation of defect sites and high specific surface area, while enabling to stabilization of NSVs. Additionally, isopropanol was both the reaction medium and the secondary hydrogen donor, which contributed to reducing the external hydrogen supplication. This finding can open broad opportunities for the rational design of novel metal-free catalysts for challenging chemical reactions.
研究领域:
催化化学
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能源材料科学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2021
·
IF 19.503
Ni Luo,Cheng Chen,Dingming Yang,Wenyuan Hu,Faqin Dong
In the field of photocatalysis , one focus is on high-performance visible light catalysis. For this study, which follows the defect engineering strategy, ultrathin two-dimensional (2D) S defect-rich MoS 2 nanosheets were created in situ by ball-milling MoS 2 nanosheets with ascorbic acid and then used for the removal of Cr(VI) from wastewater. The results show that ascorbic acid increases both the specific surface area of MoS 2 nanosheets and the concentration of S stripping-defects significantly. Of the samples, D-MoS 2 -3 (i.e., S defect-rich ultrathin 2D MoS 2 nanosheets) exhibited the best Cr(VI) adsorption capacity and photocatalytic activity thanks to its large specific surface area and a high concentration of total S defects (18.5%), 311.1% better than for P-MoS 2 (i.e., pristine MoS 2 nanosheets) (4.5%). The concentration of S point-defects in D-MoS 2 -3 is only a little greater than in P-MoS 2 , but the concentration of S stripping-defects is significantly greater. S point-defects at such a high concentration readily act as recombination centers for photogenerated carriers. By contrast, S stripping-defects that lack dangling Mo-S bonds trap photogenerated holes and add to the separation efficiency of photogenerated electron-hole pairs. As a consequence, the photocatalytic performance of D-MoS 2 -3 in removing Cr(VI) is significantly better. Given this finding, the present study offers a new design pathway and a reference for the practical application of defect engineering to ultrathin 2D materials.
研究领域:
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Lanlan Guo,Wei Zhao,Linlin Dong,Xin Shi,Guodong Wang,Rui Li,Jianliang Cao,Xueli Yang,Xiaolian Liu,Yan Wang
The construction of high-performance sensitive materials is a basis for excellent sensors. Among prior SnS 2 -based sensors, high sensing performance often accompanies high operating temperatures or expensive costs, which limits their practical use. Herein, we employed Sr doping and NaBH 4 treatment strategies to increase the S-vacancies content in the SnS 2 microflowers. Particularly, this composite sensitive material shows large specific surface area, low crystallinity and rich S-vacancies content, which enables this sensor excellent sensing properties toward NO 2 , with a response of 4.7 toward 5 ppm NO 2 at 100 °C. In addition, this sensor has a low detection limit for NO 2 as low as 0.2 ppm, which is a lower value compared to many SnS 2 -based NO 2 sensors as reported. XRD, SEM, TEM, EPR and BET characterization combined with density functional theory (DFT) calculations are adopted to illustrate the enhancement mechanism toward NO 2 of the composite sensitive materials fabricated in this work. This study provides new ideas and scientific basis for the construction of metal sulfide based NO 2 sensors, which has important theoretical significance and application value.
研究领域:
材料科学
·
传感器技术
·
计算化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）