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Hybrid AFM Technique
Published in Cai Shen, Atomic Force Microscopy for Energy Research, 2022
The oxide layers formed on metallic materials surface, such as the widely industrial used copper and iron, act as a barrier to ionic migration and show excellent resistance towards corrosion. Nevertheless, the oxide layer will undergo local degradation in some environment, like acidic chloride solution, which will reduce its corrosion resistance. Using AFM-SECM technique, the topographical changes and electrochemical reaction pathway can be monitored, which can provide key information to study the corrosion process and decrease degradation of the metallic materials. Kranz et al. have explored AFM-SECM to record the topographical changes and cooper ions generation process from a pure copper substrate in acidic chloride solution at the initial stage of pit formation [53,54]. The results show the potential of AFM-SECM to investigate localized corrosion on otherwise passive surfaces. Kranz and coworkers fabricated a suitable AFM-SECM probe by sputtering a gold layer on a commercial silicon nitride cantilever. Contact mode was used for AFM image to motor the topographical changes caused by corrosion process; generation-collection mode was used for SECM image to record the release of Cu2+ ions simultaneously as shown in Figure 4.13. In addition to copper, Kranz and Souto in-situ monitored the generation of single corrosion and growth of pit on iron surface in 0.5 M NaCl solution with AFM-SECM technique [55].
Physiology and Distribution of Anaerobic Oxidation of Methane by Archaeal Methanotrophs
Published in Susma Bhattarai Gautam, Performance Assessment and Enrichment of Anaerobic Methane Oxidising Microbial Communities from Marine Sediments in Bioreactors, 2018
Nanominerals can also be a possible mode of interspecies e-transfer in anaerobic microbial communities (Figure 2.5A). This mode of e-transfer was described between Geobacter sulfureducens and Thiobacilus denitrificans for acetate oxidation with nitrate reduction (Kato et al., 2012b). Iron oxide nanominerals (10–20 nm diameter) resulting from the microbial oxidation and reduction of iron act as electron transporter, which receives the electrons from one cell and discharges them to other cells. These conductive iron oxide nanominerals are also assumed to facilitate methanogenesis (Kato et al., 2012a). When the iron oxide nanomineral was supplied to the methanogens from rice paddy soil, the methanogenesis rates were increased (Kato et al., 2012a). Recently, addition of iron oxide was also shown to facilitate the AOM-SR in CH4 seeps (Sivan et al., 2014), however the role of these nanominerals as possible interspecies e-shuttle among ANME and SRB has to be further investigated.
Removal of dibutyl phthalate from aqueous environments using a nanophotocatalytic Fe, Ag-ZnO/VIS-LED system: modeling and optimization
Published in Environmental Technology, 2018
B. Akbari-Adergani, M. H. Saghi, A. Eslami, A. Mohseni-Bandpei, M. Rabbani
Due to its widespread production and dangerously high toxicity, many methods have been developed for the treatment of DBP from water and wastewater. Physical, chemical, biological, UV radiation, ozonation and adsorption methods have been reported as possible treatment methods for DBP [9,10]. However, many of these treatment methods are time-consuming, not cost-effective or generate excess sludge. Among the advanced oxidation processes used for phthalate pollution treatment, photocatalytic oxidation is one of the most effective methods [11,12]. Semiconductors, such as TiO2 and ZnO, can treat polluted environments using a redox process to decompose organic materials. ZnO is a nontoxic and environmentally friendly material with excellent chemical and thermal stability [13–15]. ZnO has a large energy band gap (3.37 eV) under standard conditions [16–18]. Silver (Ag) and other metals, such as iron, act as excellent neutralizers of the native defect states in semiconductors and enhance their optical properties [19,20]. Light-emitting diodes (LEDs) are environmentally friendly light sources commonly used in many industrial and domestic aspects that have also been utilized in photocatalytic processes. LEDs have desirable characteristics, such as a significantly longer lifetime and contain no toxic material, such as mercury, which makes them suitable alternatives to the UV lamps traditionally used in the design of photoreactor systems for photocatalytic treatments [21,22].