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Rare Earth Nanoparticles Prevent Retinal Degeneration Induced by Intracellular Peroxides
Published in Lajos P. Balogh, Nano-Enabled Medical Applications, 2020
Junping Chen, Swanand Patil, Sudipta Seal, James F. McGinnis
Cerium is a rare earth element of the lanthanide series and cerium oxide (CeO2) is an inorganic compound that is insoluble in water, which has routinely been used in polishing glass and jewellery, and in catalytic converters for automobile exhaust systems and other commercial applications. Although most of the rare earth elements exist in the trivalent state, cerium also occurs in a 4 state and may flip-flop between the two in a redox reaction [6–8]. + Cerium oxides are excellent oxygen buffers because of their redox capacity [9]. As a result of alterations in the cerium oxidation state, CeO2 forms oxygen vacancies or defects in the lattice structure by loss of oxygen and/or its electrons. The valence and defect structure of CeO2 is dynamic and may change spontaneously or in response to physical parameters such as temperature, the presence of other ions, and oxygen partial pressure [7, 8, 10]. Earlier studies have shown that, with a decrease in particle size, nanoceria particles demonstrate the formation of more oxygen vacancies [11, 12]. The increased surface-area-to-volume ratio that exists in a nanoparticle of ∼5 nm diameter enables CeO2 to regenerate its activity and thereby act catalytically.
The Influence of Nanoparticles on Diesel Engine Performance and Emissions
Published in Lionello Pogliani, Suresh C. Ameta, A. K. Haghi, Chemistry and Industrial Techniques for Chemical Engineers, 2020
Mamdouh Gadalla, Omar Mazen, Hany A. Elazab, Tarek M. Aboul-Fotouh, Fatma H. Ashour
Cerium oxide is mainly characterized by its ability to catalyze the combustion process by transferring oxygen atoms from its structure. Moreover, the catalytic activity is mainly based on other crucial properties, such as surface area, so using cerium oxide as nanoparticle additives will provide higher properties than bulky materials in normal size. The main role of adding nanoparticles, like cerium oxide, is to enhance combustion process by decomposing the unburnt hydrocarbon, in addition to soot emission, which resulted in reducing the amount of pollutants produced in the exhaust gas and fuel consumption. In addition, cerium oxide has shown that it can reduce the pressure in the combustion chamber which in turn, will disturb the formation of NOx as it requires high pressure to be formed and provide a smoothly efficient combustion process. Other advantage is that it can be used to treat particulate filters in diesel engines for a short term. Generally, the nanoparticles oxides enhance the combustion process and reduce the soot emissions that clog up the filter of the diesel engines, eventually, the exhaust emission will be lesser.13–15
Cerium Oxide Nanoparticles as a Novel Reactive Oxygen Modulating Nanodrug
Published in Shaker A. Mousa, Raj Bawa, Gerald F. Audette, The Road from Nanomedicine to Precision Medicine, 2020
Ece Alpaslan, Thomas J. Webster
Due to its abundance and unique chemical properties, cerium oxide (CeO2) is a technologically important material. So far, it has been used in a variety of applications, including sensors, membrane systems, fuel cells, mechanical polishing, ultraviolet absorbent, and catalysis and more recently in biotechnology, medicine, and environmental chemistry [48, 49, 59]. In nanocrystalline solids, a decrease in the particle size leads to an increase in the density of interfaces and leads to a reduction in energy for defect formation. Thus, increased levels of non-stoichiometry and electronic carrier formation have been observed as the particle size is reduced [48].
Environmental emission analysis of the engine using Botryococcus braunii marine algae with CeO2 nanoparticle additives
Published in Journal of Experimental Nanoscience, 2023
S. Karthikeyan, T. Dharmaprabhakaran, Ekrem Yanmaz, Sana Sulaiman Hamid, T. Bothichandar
Figure 8 is a graph that shows how long the combustion process takes with a full load condition. It shows that the combustion duration is shorter when the load is greater, and longer when the load is lower [18]. The addition of cerium oxide particles to the B20 blend helps to improve the atomisation of the fuel, resulting in a more even air-fuel mixture. This improved atomisation leads to more efficient combustion, resulting in a shorter combustion duration. The shorter combustion duration allows for a more complete and efficient combustion of the fuel, leading to increased power output and fuel efficiency [37]. Additionally, the improved atomisation of the fuel ensures a more even air-fuel mixture, leading to reduced emissions. A full load combustion of B20, B20 + 100ppm Al2O3, and B20 + 100ppm CeO2 is found to last 33, 28, and 24°CA, respectively [23]. This is due to the shorter combustion duration reduces heat losses due to incomplete combustion and allows for more complete combustion of the fuel. This results in higher power output and fuel efficiency as well as lower emissions. The addition of cerium oxide further reduces the combustion duration, leading to even greater improvements in power output and fuel efficiency.
The effects of the usage of silicon dioxide (SiO2) and titanium dioxide (TiO2) as nano-sized fuel additives on the engine characteristics in diesel engines: a review
Published in Biofuels, 2023
Soroush Gholami Ghanati, Battal Doğan, Murat Kadir Yeşilyurt
Another study conducted by the University of California [62] found that the dispersion of nanoparticles in the atmosphere can penetrate the leaves of plants, causing damage to plant cells and affecting their growth and photosynthesis. Similarly, Rabajczyk et al. [63] found that cerium oxide nanoparticles, also commonly used in automotive exhaust systems, can accumulate in aquatic environments and impact the growth and reproduction of marine organisms. The study concluded that releasing cerium oxide nanoparticles from exhaust emissions could have significant ecological impacts. Moreover, a study by G. Oberdörster [64] found that the released nanoparticles can significantly impact air quality. The study concluded that smaller nanoparticles could penetrate deep into the lungs, causing inflammation and other health problems. In comparison, larger nanoparticles can remain suspended in the air for an extended period, increasing exposure for humans and the environment.
Effect of sulphate and Chloride Ions on the Oxidation of Phenolic Compounds by Ozonation Catalyzed with CeO2
Published in Ozone: Science & Engineering, 2021
Iveete C. Guzmán, Julia L. Rodríguez S., T. Poznyak, Isaac Chairez
Cerium oxide (CeO2) belongs to the rare-earth oxides, it has been widely used for its exceptional luminescence, magnetic and electronic properties (Castano, O’Keefe, and Fahrenholtz 2015). The combination of CeO2 with ozone (as oxidant agent) has been tested as part of catalytic many water treatments; which is by far the most promising treatment considering its increasing of mineralization degree of organic pollutants (Afzal, Quan, and Lu 2019; Guzmán et al. 2020; Orge et al. 2011). Orge et al. (2011) showed that the synthesis method of CeO2 nanostructures affected the removal of oxalic acid, aniline, and reactive dye with ozone. In this research, the authors suggested that OH• is the main oxidant species responsible for the compound’s elimination from water, due to CeO2 promotes the ozone decomposition. Thus, CeO2 significantly increases the mineralization degree compared with conventional ozonation. Faria, Órfão, and Pereira (2008) studied ozonation of sulfanilic acid and aniline obtaining similar results over catalytic ozonation effectiveness.