CHEMOSPHERE
·
2023
·
IF 8.8
Zeyi Wang,Rong Su,Maojie Zhao,Luyao Zhang,Lu Yang,Feng Xiao,Weishan Tang,Lichuan Chen,Ping He,Dingming Yang
The application of PbO 2 for electrochemical oxidation technology is limited by its low electrocatalytic activity and short service life. Herein, based on the facile one-step electrodeposition , we prepared a boron carbide (B 4 C) and cerium (Ce) co-modified Ti/PbO 2 (Ti/PbO 2 –B 4 C–Ce) electrode to overcome these shortcomings. Compared with Ti/PbO 2 electrode, the denser surface is displayed by Ti/PbO 2 –B 4 C–Ce electrode. Meanwhile, electrochemical characterization indicates that the introduction of B 4 C and Ce significantly enhance the electrochemical performance of PbO 2 electrode. In degradation experiments, under optimized conditions (current density 20 mA cm −2 , pH 9, 0.15 M Na 2 SO 4 and 30 °C), the fully degradation of tetracycline (TC) can be completed within 30 min. Furthermore, the trapping experiment demonstrates that ∙OH and SO 4 ·- radicals have a synergistic effect in the degradation process of TC. Based on results of liquid chromatography-mass spectrometer, the generated ·OH preferentially attacks amides, phenols and conjugated double bond groups in TC. Importantly, Ti/PbO 2 –B 4 C–Ce electrode maintains a constant degradation efficiency even after 10 recycling tests, and its service life is 2.4 times of traditional Ti/PbO 2 electrode. Hence, Ti/PbO 2 –B 4 C–Ce electrode is a promising electrode for degradation of organic wastewater containing amides, phenols, and conjugated double bond groups.
研究领域:
环境科学
·
电化学工程
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Materials
·
2022
·Vol. 15
·期 17
·6028
·
IF 3.748
Wenhao Sha,Yingying Liu,Yabin Zhou,Yihua Huang,Zhengren Huang
In this study, different reaction-bonded boron carbide (RBBC) composites with a free carbon addition from 0 to 15 wt% were prepared, and the effect of the carbon content on the mechanical properties was discussed. With the free carbon addition increase from 0 to 15 wt%, the residual silicon content in the RBBC composite decreased first and then increased. Meanwhile, the strength of the RBBC composite improved first and then worsened. In the RBBC composite without free carbon, the B4C grains are obviously dissolved, the grains become facet-shape, and the grain boundary becomes straight. The microstructure of the composite was tested by SEM, and the phase composition of the composite was tested by XRD. The RBBC composite with the addition of 10 wt% free carbon has the highest flexural strength (444 MPa) and elastic modulus (329 GPa). In the composite with a 10 wt% carbon addition, the phase distribution is uniform and the structure is compact.
研究领域:
材料科学
·
机械工程
✓ 已验证
DOI
高影响因子
PROPELLANTS EXPLOSIVES PYROTECHNICS
·
2021
·Vol. 46
·期 9
·1480-1488
·
IF 1.887
Zhiping Huang,Shengliang Xu,Xinli Chen,Min Wang,Hua Yuan,Huali Zhao,Yuanyuan Zhang
Green-light emitting illuminant and green pearls that are currently being used for pyrotechnics are mainly composed of barium carbonate and polyvinyl chloride (PVC), which lead inevitably to the substantial generation of abundant harmful products for environmental pollution. There is thus considerable scope for the development of a novel emitting illuminant with an improved “green” composition instead of compositions incorporating barium based oxidants and polyvinyl chloride for environmental protection. For this purpose, a new composition composed of boron carbide, potassium perchlorate, and guanidine nitrate with a suitable burning rate of 5∼15 mm/s required for fireworks, the high luminous intensity of 34665 Cd and spectral purity of 67.1 % at a primary wavelength of 562 nm was developed. Notably, PM10 data demonstrated that the new composition generated less than half the amount of the smoke relative to the original one. More importantly, all of the safety parameters of this new formulation meet well with the standards’ requirements, i. e ., a remarkable low sensitivity to friction (0 %) and impact (8 %), relative stability to electric discharge (374.4 mJ), flame (14.0 cm) and heating (unburned, unexploded at 75 °C for 48 h), as well as a high ignition temperature of 504.0 °C and a low moisture absorption rate (0.66 %). Taken together, the new emitting illuminant developed herein showed great potential to be used for fireworks and signal flare in both military and civilian applications.
研究领域:
化学
·
材料科学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF HAZARDOUS MATERIALS
·
2024
·
IF 12.2
Lijie Duan,Mengbin Gu,Minghao Wang,Liquan Liu,Xue Cheng,Xueqi Fan,Jun Huang
Widespread detection in soils and sediments underscores the potential threats posed by persistent, bioaccumulative and toxic perfluorooctane sulfonate (PFOS) to ecosystems and organisms. Nevertheless, the formidable energy of the C-F bond imparts stability and hampers degradation. This study investigates the potential of boron carbide (B 4 C), a hard-ceramic material often utilized in armor and abrasion contexts, for degrading solid-phase PFOS through ball milling. Following a 60-minute reaction period, PFOS degradation reached 100 %, while desulfurization stabilized at 13.9 %. Defluorination initially rose to 23.7 % but subsequently displayed a gradual decline. Fluoride ions, once released, were secured and the stable reservoir surface of B 4 C during the ball-milling process, leading to the formation of B-C-B-F chemical bonds, which was confirmed through characterization by XPS, FTIR, and solid-state NMR analyses. Furthermore, intermediate byproducts formed during the degradation of PFOS, encompassing perfluoroalkyl sulfonic acids (PFSAs) and perfluoro carboxylic acids (PFCAs), were identified. Eventually, the generation of free electrons, contributing to the facilitation of degradation for both PFOS and its intermediates, was confirmed through the DPPH experiment. This identification underscores the intricacy of the PFOS degradation pathway, which encompasses the generation and subsequent breakdown of these intermediates. These discoveries hold significance for pioneering sustainable and inventive methods to combat PFOS pollution across diverse applications. Furthermore, they enrich the comprehension of how mechanical forces can be leveraged for the eco-friendly removal of PFOS contaminants.
研究领域:
环境科学
·
材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）