JOURNAL OF HAZARDOUS MATERIALS
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2024
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IF 12.2
Siyi Wang,Pengcheng Zhang,Enzhao Ma,Suwen Chen,Zijie Li,Liyong Yuan,Jianhua Zu,Lin Wang,Weiqun Shi
The removal and recovery of radioactive Sr(II) from wastewater and seawater has been of great concern due to the negative environmental impacts of nuclear energy development and the potential risk of nuclear accidents. Herein, a facile molten salt synthesis strategy was developed to systematically investigated the reaction of different types of MXenes with nitrates. Among the products, K + intercalated hierarchical titanate nanostructures (K-HTNs) obtained from the direct chemical transformation of multilayered Ti 3 C 2 T x exhibited unique layered structures, good physicochemical properties, and outstanding adsorption performance for Sr(II). The maximum adsorption capacity of Sr(II) by K-HTNs reached 204 mg·g −1 at ambient temperature, and the good regeneration and reusability of the titanate was also demonstrated. K-HTNs showed preferential selectivity for Sr(II) in different environmental media containing competing ions, and the removal efficiency of Sr(II) in real seawater was as high as 93.3 %. The removal mechanism was elaborated to be the exchange of Sr 2+ with K + /H + in the interlayers of K-HTNs, and the adsorbed Sr(II) had a strong interaction with Ti−O − termination on the titanate surface. Benefiting from the merits of rapid and scalable synthesis and excellent adsorption performance, MXene-derived K-HTNs have broad application prospects for the purification of 90 Sr-contaminated wastewater and seawater.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
INORGANIC CHEMISTRY
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2020
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IF 4.825
Guoliang Zhao,Xin Wang,Chen Xu
NH3, as one of the most massively used chemical products in the world, not only serves as the main nitrogen source of chemical fertilizers but also is considered as a promising renewable energy source. Most ammonia in industry is produced by the Haber–Bosch process under extremely high temperature and pressure conditions, which is intensively energy consuming and environmentally unfriendly. Electrocatalytic nitrogen reduction reaction (NRR) has been regarded as a promising way to produce NH3 under ambient conditions in recent years, but the research for efficient earth-abundant electrocatalysts is still highly limited. In this work, different TiO2 phases (anatase and rutile)/carbon nanocomposites with a sandwich architecture are produced by annealing MXene at different temperatures, which shows excellent electrocatalytic NRR performance. In 0.1 M Na2SO4, anatase TiO2/C composites show better NRR performance than the rutile ones, which achieve a large NH3 yield of 14.0 μg h–1 cm–2, a high Faradaic efficiency of 13.3% at −0.2 V vs a reversible hydrogen electrode, and a high electrochemical stability. The sandwich architecture of anatase TiO2 nanoparticles well-dispersed on the surface of carbon layers could increase the conductivity of TiO2 and the exposure of active sites, which could explain the improved NRR activity of anatase TiO2/C composites compared with previous work. Density functional theory calculations suggest that the energy barrier of most steps for the surface of anatase TiO2 is relatively lower than that of rutile TiO2, which could explain the better electrocatalytic NRR performance for anatase TiO2/C composites compared with the rutile ones.
研究领域:
材料科学
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电化学
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催化化学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
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IF 13.3
Feihong Wang,Qi Zhao,Hongpeng Li,Qiangshun Wu,Luyan Zhang,Yan Li,Liang Qiao,Ye Yuan,Jun Ma,Panpan Wang,Tianming Chen
Chlorophenolic pollutants pose serious threats to the aquatic ecosystem. Photocatalysis technology has broad prospects for decontamination. In this work, MXene-derived TiO 2 nanocomposites with mixed-crystal characteristics and oxygen vacancies (OVs) (E–TiO 2 @rGO) were successfully synthesized by atmosphere modulation. Compared with commercial TiO 2 and N 2 –TiO 2 @rGO (anatase phase), the rate constants of E–TiO 2 @rGO (0.06874 min −1 ) over 2,4,6-trichlorophenol (2,4,6-TCP) degradation increased 4 and 1.3 times, respectively. The enhanced photocatalytic performance was attributed to the co-existence of anatase and rutile phases. On the one hand, the mixed-crystal phase narrowed the band gap, broadening the light absorption range. On the other hand, it induced the generation of OVs, which has been demonstrated by DFT calculation. The presence of OVs improved the adsorption and activation of O 2 and H 2 O molecules, beneficial for the formation of active free radicals. In addition, the incorporation of rGO promoted the separation of electron-hole pairs. The Gibbs free energy of 2,4,6-TCP degradation revealed that the OVs and mixed-crystal could reduce the energy barrier of the rate-determining step, thereby boosting the dichlorination efficiency of 2,4,6-TCP. The superoxide free radical ( O 2 − ) was determined as the dominant active species. Finally, a possible mechanism of 2,4,6-TCP degradation with E–TiO 2 @rGO was clarified clearly. The proposed mixed-crystal defect engineering represents a novel strategy in the design and synthesis of photocatalysts.
研究领域:
环境科学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2021
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IF 9.229
Zihan Wang,Liuxin Yang,Yang Zhou,Chen Xu,Mi Yan,Chen Wu
Cross-linking network structures are critical to construct flexible and lightweight electromagnetic (EM) wave absorbers, for which effective regulation of the EM parameters is essential. Herein, a versatile strategy has been developed by interconnecting carbon fibers with NiFe-layered double hydroxide (NiFe LDH)/MXene derivatives. The large-sized flaky morphology and conductive nature of the interconnectors induce the percolation effect in the fabric networks with ultralow addition. As such, efficient adjustment of the EM parameters can be achieved by tuning the content of the interconnectors around the percolation threshold, giving rise to an optimal reflection loss (RL) of −58.0 dB and a wide effective absorption band (EAB) of 7.0 GHz at a thickness of 2.5 mm under the incorporation of 7.0 wt % NiFe LDH/MXene. This work provides insights on constructing percolation networks and effective manipulation of electronic and magnetic properties, which can be extended to various areas such as sensing, catalysis, and energy storage.
研究领域:
材料科学
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电磁学
✓ 已验证
DOI
PubMed
高影响因子
Energy & Environmental Materials
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2024
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IF 13
Hui Zhang,Xingwu Zhai,Xin Cao,Zhihao Liu,Xinfeng Tang,Zhihong Hu,Hang Wang,Zhandong Wang,Yang Xu,Wei He,Wei Zheng,Min Zhou,ZhengMing Sun
Since 2019, research into MXene derivatives has seen a dramatic rise; further progress requires a rational design for specific functionality. Herein, through a molecular design by selecting suitable functional groups in the MXene coating, we have implemented the dual N doping of the derivatives, nitrogen-doped TiO 2 @nitrogen-doped carbon nanosheets (N-TiO 2 @NC), to strike a balance between the active anatase TiO 2 at low temperatures, and carbon activation at high temperatures. The NH 3 reduction environment generated at 400 °C as evidenced by the in situ pyrolysis SVUV-PIMS process is crucial for concurrent phase engineering. With both electrical conductivity and surface Na + availability, the N-TiO 2 @NC achieves higher interface capacitive-like sodium storage with long-term stability. More than 100 mAh g −1 is achieved at 2 A g −1 after 5000 cycles. The proposed design may be extended to other MXenes and solidify the growing family of MXene derivatives for energy storage.
研究领域:
材料科学
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能源存储
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
Nano Energy
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2021
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IF 17.881
Yuantao Yan,Yu-Shi He,Xiaoli Zhao,Wanyu Zhao,Zi-Feng Ma,Xiaowei Yang
Nanostructured silicon-based materials are the promising anodes for next-generation lithium-ion batteries. However, as the result of the weak adhesion of solid-electrolyte interphase (SEI) to Si, the fracture, exfoliation and subsequent regrowth of SEI layer on the expanded Si remains unsolved, leading to low initial Coulombic efficiency (ICE) (50–80%). Herein, the Ti‒Si covalent bond between nano-Si and MXene-derived artificial SEI layer is elaborately introduced, to effectively strengthen the interfacial stability and suppress the excessive interfacial side reaction. Upon the three-times expansion during first cycling, the as-obtained anodes with the ultrathin SEI still deliver a high ICE of 91.4%. Due to the stable interfacial ionic conduction, remarkable capacity retention of 90.7% after 1000 cycles at 5 A g −1 with an average Coulombic efficiency of 99.8% could be maintained. This strategy provides new insight into designing durable alloy anodes from the point of the interfacial adhesion strength .
研究领域:
材料科学
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电化学
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纳米科技
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能源存储
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界面化学
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锂离子电池
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）