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Group IVA of 2D Xenes materials (Silicene, Germanene, Stanene, Plumbene)
Published in Zongyu Huang, Xiang Qi, Jianxin Zhong, 2D Monoelemental Materials (Xenes) and Related Technologies, 2022
Yundan Liu, Dan Mu, Jincheng Zhuang
Graphene was firstly obtained in experiment by mechanical exfoliation in 2004, which verified a typical stable freestanding 2D material.1 Graphene possesses unique properties in optical, electrical, and mechanical applications, which have attracted widespread attention in the study of materials, physics, chemistry, and semiconductors.2–4 At the same time, the discovery of graphene has also opened the new research era on exploration and application of other new two-dimensional materials. In the periodic table, silicon, germanium, stannum, and lead are in the same main group of carbon (group IV). They have a similar valence electron configuration to carbon, and their 2D allotropes are called silicene, germanene, stanene, and plumene, respectively.5 Graphene is composed of a monoatomic layer of covalently bonded sp2 hybridized carbon atoms arranged in a hexagonal honeycomb lattice structure.1 However, silicon, germanium, stannum, and lead atoms tend to adopt a mixed degree of sp2–sp3 hybridization-formed silicene, germanene, stanene, and plumene with buckled honeycomb structure. Motivated by recent advances in the exciting class of group IV Xenes, herein we review the literature to date and connect the structure, properties, synthesis, and application of these elemental 2D materials.
Bioremediation: Plants and Microbes for Restoration of Heavy Metal Contaminated Soils
Published in Jos T. Puthur, Om Parkash Dhankher, Bioenergy Crops, 2022
Harsh Kumar, Shumailah Ishtiyaq, Mayank Varun, Paulo J.C. Favas, Clement O. Ogunkunle, Manoj S. Paul
Lead (Pb) is a primary group member of the carbon group with an atomic number of 82. It is a light, malleable, poor metal, and widely distributed. Lead is the 2nd most significant and toxic heavy metal; it adsorbs mainly in the top soil, while its concentration reduces as soil depth increases (de Abreu et al. 1998). It exists in the environment as dust, fumes, mist, and minerals. When it is absorbed into the soil, it is very hard to remove. It is listed by EPA in category B1, as a probable human carcinogen (Evangelou 1998). Considerably affected soil contains 400-800 mg Pb kg-1 soil. The average Pb concentrations ranged from 2-200 mg kg-1 soil, and some researchers have indicated that less polluted soils contain less than 100 mg kg-1. High Pb content is present in ‘soil A horizon’, while dissolved Pb in soil water is just around 0.005-0.13% of total soil Pb, though bioavailable for uptake by plants (Watmough et al. 2004).
Borate Phosphor for Phototherapy Application
Published in S. K. Omanwar, R. P. Sonekar, N. S. Bajaj, Borate Phosphors, 2022
Lead compound is a relatively un-reactive post-transition metal. Its weak, metallic character is illustrated by its amphoteric nature. Compounds of lead are usually found in the 2+ oxidation state rather than the 4+ state common with lighter members of the carbon group.
Preparation and surface modification of ZnO nanopowder lubricating additive by dielectric barrier discharge plasma assisted ball milling
Published in Particulate Science and Technology, 2023
Haifeng Liao, Haitao Yan, Yukun Wei, Xianbin Hou, Jinhong Du, Zibin Yin, Yongjian Wang, Leyang Dai
Figure 4 shows the results of FTIR of ZnO nanopowder modified by oleic acid. The absorption peak at 2920 cm−1 and 2850 cm−1 were attributed to the C–H stretching vibration of –CH2 and –CH3, respectively, in oleic acid. The absorption peak at 1652 cm−1 was caused by the bridging of hydroxyl groups on the surface of ZnO nanopowder. The absorption peak at 1077 cm−1 was the stretching vibration of –C–C– which was adjacent to the carbon group and the absorption peak of carbon chain in oleic acid. The absorption peak at 1615 cm−1 was attributed to the vibration of –COO–Zn (Han et al. 2016). The information illustrated that chemical adsorption of –COO–Zn had been occurred between the carboxyl group of oleic acid and the hydroxyl group of ZnO.
Lipase catalysis: an environmentally friendly production for polyol esters (biolubricant) from microalgae oil
Published in Environmental Technology, 2022
Togayhan Kutluk, Bahar Gürkaya Kutluk
After Novozymes 435 catalysed esterification reaction GC chromatogram of TMP esters was shown in Figure 11 with remarkable TMP-triester (92%) content. After the esterification process, three types of polyol esters were composed which are monoester (ME), diester (DE) – OH groups were partially esterified and triester (TE) when – OH groups in TMP were fully esterified. The appeared peaks were described depending on the number of the alkyl carbon group attached to the TMP backbones. The esters formed were identified by comparing the obtained chromatograms with studies [40,41]. The type of alcohol used in lubricant production affects the ester content. In the production of microalgae, oil triesters were obtained as a result of reactions carried out in the presence of TMP. This is because TMP has three –OH groups.
Fabrication and performance of boron doped textured diamond coated tool
Published in Surface Engineering, 2020
Yanbin Chen, Daohui Xiang, Haoren Feng, Bangfu Wu, Xiaoxiao Niu
The surface morphology and cross-section of BDUTD, BDETD and BDGTD films are also examined using SEM, as presented in Figure 4. Figure 4(a) shows the BDUTD film, it can be seen that the grain size of BDUTD film is obviously refined, and the surface roughness value decreases significantly, which is as low as 265.4 nm. Owing to the presence of boron, the grain size shows a decreasing trend and the activity of the carbon group can be enhanced to promote secondary nucleation [19,20]. Figure 4(c,e) shows the BDETD and BDGTD films, respectively. As can be observed in both sides of the dotted line area of Figure 4(c,e) that the surface roughness of the diamond film increased slightly, and its roughness value is about 330 nm. From the BDTD films, the grains have clear edges and corners and preferential (111) crystallographic orientation. The adhesion strength between the BDTD film and the substrate is improved owing to texture further enhanced the mechanical interactions. Figure 4(b,d,f) shows the cross-section of BDUTD, BDETD and BDGTD films, respectively. Compared with UDD film, the thickness of three types of BDD film increases significantly, which film thickness of 18 µm can be seen.