ENVIRONMENTAL SCIENCE & TECHNOLOGY
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2022
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IF 11.357
Hongchao Li,Na Yuan,Jieshu Qian,Bingcai Pan
The environmentally benign Mn oxides play a crucial role in the transformation of organic contaminants, either through catalytically decomposing oxidants, e.g., peroxymonosulfate (PMS), or through directly oxidizing the target pollutants. Because of their dual roles and the complex surface chemical reactions, the mechanism involved in Mn oxide-catalyzed PMS activation processes remains obscure. Here, we clearly elucidate the mechanism involved in the Mn2O3 catalyzed PMS activation process by means of separating the PMS activation and the pollutant oxidation process. Mn2O3 acts as a shuttle that mediates the electron transfer from organic substrates to PMS, accompanied by the redox cycle of surface Mn(IV)/Mn(III). Multiple experimental results indicate that PMS is bound to the surface of Mn2O3 to form an inner-sphere complex, which then decomposes to form long-lived surface reactive Mn(IV) species, without the generation of sulfate radicals (SO4•–) and hydroxyl radicals (HO•). The surface reactive Mn(IV) species are proposed to be responsible for the degradation of organic contaminants (e.g., phenol) and the formation of singlet oxygen (1O2), followed by the regeneration of the surface Mn(III) sites on Mn2O3. This study advances the fundamental understanding of the underlying mechanism involved in transition metal oxide-catalyzed PMS activation processes.
研究领域:
环境科学
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催化化学
✓ 已验证
DOI
高影响因子
ELECTROCHIMICA ACTA
·
2023
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IF 6.6
Bo Xiao,Dongjia Li,Xinyi Dai,Yawei Wei,Yunchao Liao,Chao Wang,Fangli Ji,Fuzhong Wu
The low cycling stability of LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811) is due to structural instability during lithium insertion and removal and strong surface reactivity, and it limits widespread application. In this study, a layer of LiCoPO 4 was coated on NCM811, and electrochemical tests showed that the material had excellent high-voltage electrochemical properties. The NCM811 sample coated with 1.0 wt% LiCoPO 4 (NCM-LCP1) had a capacity of 156.5 mAh g −1 after 100 cycles at 3–4.6 V and a retention rate of 87.47%. In contrast, the capacity of unmodified NCM811 was only 96.9 mAh g −1 , with a retention rate of 55.9%. An NCM-LCP1/graphite full cell demonstrated a capacity retention rate of 87.46% over 200 cycles at 3–4.3 V. By combining EIS and postcycle analyses, the stability and protection mechanism of the LiCoPO 4 layer under high voltage was confirmed. The LiCoPO 4 layer effectively prevented particle fragmentation and kept the structure stable. It also suppressed side reactions on the cathode surface. This work offers a new methodology for modifying NCM811 materials operated at 4.6 V.
研究领域:
材料科学
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电化学
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电池技术
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
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2025
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IF 6.9
Fangshan Li,Wenbin Ye,Yuchao Ke,Chun Yang,Fukai Chu,Bibo Wang,Lei Song,Yuan Hu,Weizhao Hu
Ethylene propylene diene monomer rubber (EPDM), celebrated for its superior weatherability, chemical resistance, and elasticity, is widely used in seals, automotive parts, and construction. However, its performance under extreme conditions like high-frequency loads and heat is limited by poor thermal conductivity, energy loss, and rapid degradation. Therefore, enhancing its high-temperature flame retardancy and thermal stability is critical to expanding its use in advanced fields such as high-power electronics and thermal management systems. This work fabricated a surface-modified reactive boron nitride hybrid nanoparticle (h-BN-APVAC) that promoted the formation of high-quality char layers in EPDM during combustion. Additionally, it enhanced the thermal stability of EPDM through dynamic thermal exchange-mediated crosslinking of its sulfur network via h-BN nanosheets. Compared to pure EPDM, the material exhibited significant reductions in heat release rate, total heat release, and total smoke production by 37.5 %, 37.0 %, and 46.1 %, respectively. Furthermore, the hybrid demonstrated high retention of mechanical properties under prolonged high-temperature aging, confirming the efficacy of h-BN-APVAC in reinforcing the thermal stability of EPDM. Overall, this study established a high-performance flame-retardant EPDM system, providing a foundational material solution for applications in extreme environmental conditions.
研究领域:
材料科学
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高分子科学
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纳米技术
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消防安全工程
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化学工程
✓ 已验证
产品关联
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2025
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IF 13.2
Zichen Zheng,Kewei Liu,Yiwen Zhou,Kaichun Xu,Liangchao Guo,Marc Debliquy,Carla Bittencourt,Chao Zhang
The simultaneous optimization of sensitivity and humidity tolerance in metal oxide semiconductor (MOS)-based gas sensors remains a critical challenge for practical volatile compound (VOC) detection. This work demonstrates a defect engineering strategy to modulate the electronic and surface properties of NiWO 4 microstructures through controlled hydrogen reduction. Systematic annealing protocols induced a high density of oxygen vacancy (O V ) via selective oxygen removal, as confirmed by structural and spectroscopic characterization. The engineered oxygen vacancies exhibited dual functionality: (1) enhanced bulk electron transport through improved conductivity and (2) boosted surface reactivity via optimized adsorption sites. The optimized NiWO 4 sensor achieved exceptional performance for 1-octen-3-ol detection at 40 ppm, including a high response value (R a /R g = 20.6), fast response time (22 s), and remarkable relative humidity resilience (19.7 % response drift across 20–80 % RH). The mechanism underlying enhanced sensing performance is elucidated through an oxygen adsorption model and molecular dynamics (MD) simulation. This study establishes hydrogen reduction as an effective approach for developing durable NiWO 4 sensors with combined high sensitivity and environmental stability, advancing their applicability in real-world atmospheric monitoring systems.
研究领域:
材料科学
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化学传感器
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纳米技术
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表面化学
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环境监测
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）