Pub Date : 2018-07-11DOI: 10.5772/INTECHOPEN.75776
D. Egirani, Mohd Talib Latif, Nanfe. R. Poyi, Napoleon Wessey, S. Acharjee
Iron oxides are chemical complexes which occur naturally, comprising iron and oxygen. Here, together, 16 types of iron oxides and oxyhydroxides have been identified. These two components of oxides are widely spread naturally. They are vital to humans and useful in most geological and biological activities. In addition, they are useful as pigments and catalyst in industries and hemoglobin in blood circulation. The interplay and conversion of these components from one form to another are essentially controlled by bacterial species. These contain 70 and 72% iron, respectively. Furthermore, iron ores are classified in terms of occurrence. Banded iron formation (BIF) comprises 15% iron, com prising minerals of iron that are bedded besides silica. Beneficiation processes of iron ore generate dust in the atmosphere, acid mine drainage in the ecosystem and metallic iron for steelmaking. Beneficiation process requires dissolution of minerals surrounding the ore and the release of metals and cement matrix into water courses. These generates acid leading to acid mine drainage. Therefore, there is a need for impact assessment of the environment in the planned beneficiation cycle. Sustainable beneficiation must be done to reduce impact on the natural, social or economic environment.
{"title":"Genesis, Uses and Environment Implications of Iron Oxides and Ores","authors":"D. Egirani, Mohd Talib Latif, Nanfe. R. Poyi, Napoleon Wessey, S. Acharjee","doi":"10.5772/INTECHOPEN.75776","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.75776","url":null,"abstract":"Iron oxides are chemical complexes which occur naturally, comprising iron and oxygen. Here, together, 16 types of iron oxides and oxyhydroxides have been identified. These two components of oxides are widely spread naturally. They are vital to humans and useful in most geological and biological activities. In addition, they are useful as pigments and catalyst in industries and hemoglobin in blood circulation. The interplay and conversion of these components from one form to another are essentially controlled by bacterial species. These contain 70 and 72% iron, respectively. Furthermore, iron ores are classified in terms of occurrence. Banded iron formation (BIF) comprises 15% iron, com prising minerals of iron that are bedded besides silica. Beneficiation processes of iron ore generate dust in the atmosphere, acid mine drainage in the ecosystem and metallic iron for steelmaking. Beneficiation process requires dissolution of minerals surrounding the ore and the release of metals and cement matrix into water courses. These generates acid leading to acid mine drainage. Therefore, there is a need for impact assessment of the environment in the planned beneficiation cycle. Sustainable beneficiation must be done to reduce impact on the natural, social or economic environment.","PeriodicalId":14641,"journal":{"name":"Iron Ores and Iron Oxide Materials","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82199474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-07-11DOI: 10.5772/INTECHOPEN.73216
H. Nadaroğlu, S. Çiçek, Hicran Onem, Azize AlayliGungor
In this study, loaded Luffa sponge membrane forms were modified with ZnO, Fe 3 O 4 , ZnO/ Fe 3 O 4 nanoparticles (NPs) to remove of Direct Blue 15 (DB15), which is a carcinogenic azo dye in aqueous solution. ZnO and Fe 3 O 4 NPs were synthesized using purified peroxidase enzymes from Euphorbia amygdaloides using green synthesis method. Adsorption of DB15 azo dyes was separately studied with membrane forms (LS-pure, LS-ZnO, LS-Fe 3 O 4 , and LS-ZnO/Fe 3 O 4 ). Optimum contact time, optimum pH, optimum temperature, opti - mum dye concentration, and optimum LS amount were found as 45 min, pH 8.0, 20°C, 200 mg/L, and 0.025 g in line with the optimization studies, respectively. The obtained membrane forms were characterized using SEM, FT-IR, and XRD techniques. According to obtained results, NPs loaded LS membrane forms are promising in removal of DB15 from textile wastewater contaminated water.
{"title":"The Investigation of Removing Direct Blue 15 Dye from Wastewater Using Magnetic Luffa sponge NPs","authors":"H. Nadaroğlu, S. Çiçek, Hicran Onem, Azize AlayliGungor","doi":"10.5772/INTECHOPEN.73216","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.73216","url":null,"abstract":"In this study, loaded Luffa sponge membrane forms were modified with ZnO, Fe 3 O 4 , ZnO/ Fe 3 O 4 nanoparticles (NPs) to remove of Direct Blue 15 (DB15), which is a carcinogenic azo dye in aqueous solution. ZnO and Fe 3 O 4 NPs were synthesized using purified peroxidase enzymes from Euphorbia amygdaloides using green synthesis method. Adsorption of DB15 azo dyes was separately studied with membrane forms (LS-pure, LS-ZnO, LS-Fe 3 O 4 , and LS-ZnO/Fe 3 O 4 ). Optimum contact time, optimum pH, optimum temperature, opti - mum dye concentration, and optimum LS amount were found as 45 min, pH 8.0, 20°C, 200 mg/L, and 0.025 g in line with the optimization studies, respectively. The obtained membrane forms were characterized using SEM, FT-IR, and XRD techniques. According to obtained results, NPs loaded LS membrane forms are promising in removal of DB15 from textile wastewater contaminated water.","PeriodicalId":14641,"journal":{"name":"Iron Ores and Iron Oxide Materials","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74099429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-07-11DOI: 10.5772/INTECHOPEN.72808
Mehmet Çelikdemir, M. Sarıkaya, T. Depci, RamazanAydogmus, A. Yucel
In the present study, calcination properties of Hekimhan-Deveci siderite (FeCO 3 ) ore and the effect of calcination process before the pelletization on strength of pellet were inves tigated and evaluated. Two different calcination processes were followed. One of them is the traditional calcination process and the other one is microwave assisted calcination process which is a new process for siderite ore. The characterization of the calcined and uncalcined siderite ore was done using X-ray diffraction, X-ray fluorescence spectrom etry and thermogravimetric analysis. The physical and mechanical properties of pellets which were obtained using the raw siderite and the calcined siderite were compared with each other. As a result of experimental studies, it was found that the calcination process decreased the milling time, causing the significant energy saving and the most suitable calcination process for siderite ore was found as 15 min at 700°C temperature. It was the first time that the calcination process of the siderite ore was achieved by microwave by adding 30 wt% sucrose as a thermal auxiliary. The microwave conditions were deter - mined as 900 W at 3 min. In 3 min, the temperature of the siderite ore increased up to 1100°C and 32.14% weight loss for the sample was achieved. different bentonite ratios (8, 9, 10, 11, 12%) to the raw siderite and the calcined siderite which were milled for 90 and 60 min, respectively. The raw pellets were heated at a temperature of 1300°C which is the recrystallization temperature of hematite. Recrystallization was confirmed by SEM images and the process was confirmed to be successful. The product pellets were tested for compressive strength. The highest level of pellet strength was determined from the material obtained by grinding calcined siderite for 90 min. This pellet, which has a maximum strength value of 268 kgf, has an average durability of 28% higher than the pellet of the raw siderite.
{"title":"Calcination and Pelletizing of Siderite Ore","authors":"Mehmet Çelikdemir, M. Sarıkaya, T. Depci, RamazanAydogmus, A. Yucel","doi":"10.5772/INTECHOPEN.72808","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.72808","url":null,"abstract":"In the present study, calcination properties of Hekimhan-Deveci siderite (FeCO 3 ) ore and the effect of calcination process before the pelletization on strength of pellet were inves tigated and evaluated. Two different calcination processes were followed. One of them is the traditional calcination process and the other one is microwave assisted calcination process which is a new process for siderite ore. The characterization of the calcined and uncalcined siderite ore was done using X-ray diffraction, X-ray fluorescence spectrom etry and thermogravimetric analysis. The physical and mechanical properties of pellets which were obtained using the raw siderite and the calcined siderite were compared with each other. As a result of experimental studies, it was found that the calcination process decreased the milling time, causing the significant energy saving and the most suitable calcination process for siderite ore was found as 15 min at 700°C temperature. It was the first time that the calcination process of the siderite ore was achieved by microwave by adding 30 wt% sucrose as a thermal auxiliary. The microwave conditions were deter - mined as 900 W at 3 min. In 3 min, the temperature of the siderite ore increased up to 1100°C and 32.14% weight loss for the sample was achieved. different bentonite ratios (8, 9, 10, 11, 12%) to the raw siderite and the calcined siderite which were milled for 90 and 60 min, respectively. The raw pellets were heated at a temperature of 1300°C which is the recrystallization temperature of hematite. Recrystallization was confirmed by SEM images and the process was confirmed to be successful. The product pellets were tested for compressive strength. The highest level of pellet strength was determined from the material obtained by grinding calcined siderite for 90 min. This pellet, which has a maximum strength value of 268 kgf, has an average durability of 28% higher than the pellet of the raw siderite.","PeriodicalId":14641,"journal":{"name":"Iron Ores and Iron Oxide Materials","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82783871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-07-11DOI: 10.5772/INTECHOPEN.76729
Guangrong Li
Probably due to large national land area and multi-period orogeny, from the view of metallogeny, lots of iron deposits developed in China, and the proven total reserves of iron ores are relatively abundant, but mainly low-grade ores. For years, China’s iron ore reserves are far from being able to meet the requirement of rapid development of steel industry. China is the world’s largest importer of iron ore, whose imports accounted for one-third of the world’s total in recent decades; however, the buyer has not the final say. The strategic importance of iron ore resources in national economy not only depends on the social value and economic value created by the iron ore exploitation, but also depends on whether the requirements of the steel industry and steel downstream industry, and safety ensuring, economy and sustainability of steel and steel downstream industry. Herein, the iron mineral processing and metallurgy technology are also briefly illustrated.
{"title":"The Chinese Iron Ore Deposits and Ore Production","authors":"Guangrong Li","doi":"10.5772/INTECHOPEN.76729","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.76729","url":null,"abstract":"Probably due to large national land area and multi-period orogeny, from the view of metallogeny, lots of iron deposits developed in China, and the proven total reserves of iron ores are relatively abundant, but mainly low-grade ores. For years, China’s iron ore reserves are far from being able to meet the requirement of rapid development of steel industry. China is the world’s largest importer of iron ore, whose imports accounted for one-third of the world’s total in recent decades; however, the buyer has not the final say. The strategic importance of iron ore resources in national economy not only depends on the social value and economic value created by the iron ore exploitation, but also depends on whether the requirements of the steel industry and steel downstream industry, and safety ensuring, economy and sustainability of steel and steel downstream industry. Herein, the iron mineral processing and metallurgy technology are also briefly illustrated.","PeriodicalId":14641,"journal":{"name":"Iron Ores and Iron Oxide Materials","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75329076","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-07-11DOI: 10.5772/INTECHOPEN.75436
B. Peters, Baniasadi Maryam, M. Baniasadi
The blast furnace iron making is the oldest but still the main method to produce liquid iron through sequential reduction processes of iron ore materials. Despite the existence of several discrete and continuous numerical models, there is no global method to provide detailed information about the processes inside the furnaces. The extended discrete element method known as XDEM is an advance numerical tool based on Eulerian–Lagrangian framework which is able to cover more information about the blast furnace process. Within this platform, the continuous phases such as gas and liquid phases are coupled to the discrete entities such as coke and iron ore particles through mass, momentum and energy exchange. This method has been applied to the shaft, cohesive zone, dripping zone and hearth of the blast furnace. In this chapter, the mathematical and numerical methods implemented in the XDEMmethod are described, and the results are discussed.
{"title":"The Extented Discrete Element Method (XDEM): An Advanced Approach to Model Blast Furnace","authors":"B. Peters, Baniasadi Maryam, M. Baniasadi","doi":"10.5772/INTECHOPEN.75436","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.75436","url":null,"abstract":"The blast furnace iron making is the oldest but still the main method to produce liquid iron through sequential reduction processes of iron ore materials. Despite the existence of several discrete and continuous numerical models, there is no global method to provide detailed information about the processes inside the furnaces. The extended discrete element method known as XDEM is an advance numerical tool based on Eulerian–Lagrangian framework which is able to cover more information about the blast furnace process. Within this platform, the continuous phases such as gas and liquid phases are coupled to the discrete entities such as coke and iron ore particles through mass, momentum and energy exchange. This method has been applied to the shaft, cohesive zone, dripping zone and hearth of the blast furnace. In this chapter, the mathematical and numerical methods implemented in the XDEMmethod are described, and the results are discussed.","PeriodicalId":14641,"journal":{"name":"Iron Ores and Iron Oxide Materials","volume":"121 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79444474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-07-11DOI: 10.5772/INTECHOPEN.73164
S. Moraes, J. Lima, T. R. Ribeiro
The iron ore production has significantly expanded in recent years, owing to increasing steel demands in developing countries. However, the content of iron in ore deposits has deteriorated and low-grade iron ore has been processed. The fines resulting from the concentration process must be agglomerated for use in iron and steelmaking. This chapter shows the status of the pelletizing process with a special focus on binders. Bentonite is the most used binder due to favorable mechanical and metallurgical pellet properties, but it contains impurities especially silica and alumina. The importance of many researches concerning alternative binders is also discussed in this chapter. Better quality wet, dry, preheated, and fired pellets can be produced with combined binders, such as organic and inorganic salts, when compared with bentonite-bonded pellets. While organic binders provide sufficient wet and dry pellet strengths, inorganic salts provide the required preheated and fired pellet strengths.
{"title":"Iron Ore Pelletizing Process: An Overview","authors":"S. Moraes, J. Lima, T. R. Ribeiro","doi":"10.5772/INTECHOPEN.73164","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.73164","url":null,"abstract":"The iron ore production has significantly expanded in recent years, owing to increasing steel demands in developing countries. However, the content of iron in ore deposits has deteriorated and low-grade iron ore has been processed. The fines resulting from the concentration process must be agglomerated for use in iron and steelmaking. This chapter shows the status of the pelletizing process with a special focus on binders. Bentonite is the most used binder due to favorable mechanical and metallurgical pellet properties, but it contains impurities especially silica and alumina. The importance of many researches concerning alternative binders is also discussed in this chapter. Better quality wet, dry, preheated, and fired pellets can be produced with combined binders, such as organic and inorganic salts, when compared with bentonite-bonded pellets. While organic binders provide sufficient wet and dry pellet strengths, inorganic salts provide the required preheated and fired pellet strengths.","PeriodicalId":14641,"journal":{"name":"Iron Ores and Iron Oxide Materials","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80701387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-07-11DOI: 10.5772/INTECHOPEN.73228
Y. Maeda
It was possible to prepare a hematite film by electrochemical deposition of iron oxide in aqueous solution and its heat treatment at 500 C or higher temperature in air. The deposition process of iron oxide film from current and potential pulse methods was mentioned in relation to the equilibrium potential for iron oxide. The hematite in aqueous solution showed a clear photoanodic current due to visible light irradiation. The photo-oxidation response of hematite electrode to organic and inorganic materials in aqueous solution was summarized through the examples of citric acid, Pb and aniline.
{"title":"Photoelectrochemistry of Hematite","authors":"Y. Maeda","doi":"10.5772/INTECHOPEN.73228","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.73228","url":null,"abstract":"It was possible to prepare a hematite film by electrochemical deposition of iron oxide in aqueous solution and its heat treatment at 500 C or higher temperature in air. The deposition process of iron oxide film from current and potential pulse methods was mentioned in relation to the equilibrium potential for iron oxide. The hematite in aqueous solution showed a clear photoanodic current due to visible light irradiation. The photo-oxidation response of hematite electrode to organic and inorganic materials in aqueous solution was summarized through the examples of citric acid, Pb and aniline.","PeriodicalId":14641,"journal":{"name":"Iron Ores and Iron Oxide Materials","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74507650","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-07-11DOI: 10.5772/INTECHOPEN.74176
Elena-Alina Moacă, Elena Dorina Coricovac, Codruta MarinelaSoica, I. Pinzaru, C. Păcurariu, C. Dehelean
The broad area of magnetic iron oxide nanoparticle (M-IONP) applications and their exclusive physico-chemical characteristics (superparamagnetic properties per se , solu-bility and stability in aqueous solutions, and high bioavailability in vivo ) make these nanoparticles suitable candidates for biomedical uses. The most employed magnetic iron oxides in the biomedical field are magnetite and maghemite. Cancer represents a complex pathology that implies multiple mechanisms and signaling pathways, this complexity being responsible for the increased resistance to therapy and the lack of an effective curative treatment. A potential useful alternative was considered to be the use of magnetic iron nanoparticles. The M-IONPs proved to be effective as contrast agents in magnetic resonance imaging, as drug delivery carriers for different therapeutic agents, in magnetic cell separation assays, and are suitable to be engineered in terms of size, targeted delivery and substance release. Moreover, their in vivo administration was considered safe, and recent studies indicated their efficiency as anticancer agents. This chap - ter aims to furnish an overview regarding the physico-chemical properties of M-IONPs (mainly magnetite, maghemite and hematite), the synthesis methods and their in vitro biological impact on healthy and cancer cell lines, by describing their potential mecha- nism of action—enucleation, apoptosis or other mechanisms.
{"title":"Preclinical Aspects on Magnetic Iron Oxide Nanoparticles and Their Interventions as Anticancer Agents: Enucleation, Apoptosis and Other Mechanism","authors":"Elena-Alina Moacă, Elena Dorina Coricovac, Codruta MarinelaSoica, I. Pinzaru, C. Păcurariu, C. Dehelean","doi":"10.5772/INTECHOPEN.74176","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.74176","url":null,"abstract":"The broad area of magnetic iron oxide nanoparticle (M-IONP) applications and their exclusive physico-chemical characteristics (superparamagnetic properties per se , solu-bility and stability in aqueous solutions, and high bioavailability in vivo ) make these nanoparticles suitable candidates for biomedical uses. The most employed magnetic iron oxides in the biomedical field are magnetite and maghemite. Cancer represents a complex pathology that implies multiple mechanisms and signaling pathways, this complexity being responsible for the increased resistance to therapy and the lack of an effective curative treatment. A potential useful alternative was considered to be the use of magnetic iron nanoparticles. The M-IONPs proved to be effective as contrast agents in magnetic resonance imaging, as drug delivery carriers for different therapeutic agents, in magnetic cell separation assays, and are suitable to be engineered in terms of size, targeted delivery and substance release. Moreover, their in vivo administration was considered safe, and recent studies indicated their efficiency as anticancer agents. This chap - ter aims to furnish an overview regarding the physico-chemical properties of M-IONPs (mainly magnetite, maghemite and hematite), the synthesis methods and their in vitro biological impact on healthy and cancer cell lines, by describing their potential mecha- nism of action—enucleation, apoptosis or other mechanisms.","PeriodicalId":14641,"journal":{"name":"Iron Ores and Iron Oxide Materials","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81742138","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2018-01-26DOI: 10.5772/INTECHOPEN.73227
M. Seki
Epitaxial films of Rh-substituted α-Fe 2 O 3 were fabricated by a pulsed laser deposition technique, and their photoelectrochemical characteristics were investigated for the development of visible light-responsive photoanodes for water splitting. The photocurrent in the films upon irradiation in the visible region was significantly enhanced after Rh substitution. Moreover, a near-infrared photocurrent was clearly observed for Rh:Fe 2 O 3 photoanodes, whereas no photoresponse could be detected for the α-Fe 2 O 3 films. These improved photoelectrochemical properties are attributed to the increased light absorp- tion due to the hybridization of Rh-4 d states and O-2 p states at the valence band maximum. Moreover, Rh substitution also strongly influences the photocarrier transport properties of the films. The electrical conductivity of Rh:Fe 2 O 3 is higher than that for α-Fe 2 O 3 by two orders of magnitude, which is possibly due to the extended 4 d orbitals of the Rh 3+ ions. Thus, the improved electrical properties may lead to an increased photocurrent by lowering the recombination rate of photogenerated carriers.
{"title":"Bandgap-Engineered Iron Oxides for Solar Energy Harvesting","authors":"M. Seki","doi":"10.5772/INTECHOPEN.73227","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.73227","url":null,"abstract":"Epitaxial films of Rh-substituted α-Fe 2 O 3 were fabricated by a pulsed laser deposition technique, and their photoelectrochemical characteristics were investigated for the development of visible light-responsive photoanodes for water splitting. The photocurrent in the films upon irradiation in the visible region was significantly enhanced after Rh substitution. Moreover, a near-infrared photocurrent was clearly observed for Rh:Fe 2 O 3 photoanodes, whereas no photoresponse could be detected for the α-Fe 2 O 3 films. These improved photoelectrochemical properties are attributed to the increased light absorp- tion due to the hybridization of Rh-4 d states and O-2 p states at the valence band maximum. Moreover, Rh substitution also strongly influences the photocarrier transport properties of the films. The electrical conductivity of Rh:Fe 2 O 3 is higher than that for α-Fe 2 O 3 by two orders of magnitude, which is possibly due to the extended 4 d orbitals of the Rh 3+ ions. Thus, the improved electrical properties may lead to an increased photocurrent by lowering the recombination rate of photogenerated carriers.","PeriodicalId":14641,"journal":{"name":"Iron Ores and Iron Oxide Materials","volume":"23 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-01-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78946406","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2017-12-20DOI: 10.5772/INTECHOPEN.72418
R. Baca
Today manufacturing stages in electronic device industry of wide-scale production can be restricted due to the high costs resulting from energy consumption, the use of organic solvents, production of hazardous intermediates, and formation of waste products leading to environmental pollution and several biological risks which damage society’s ability to sustain the planet for future generations. As recycled material resource based on iron oxide, the Mn-Zn ferrite is an interesting candidate. In the last decades, this material has been manufactured by using ceramic process technologies to design magnetic devices as components useful in switching mode electronic systems. However, these processing technologies have generated negative environmental impact as emission of toxic gases and higher use of energy resources. The Mn-Zn ferrites employed in consumer electronics deteriorate the earth when its final placement as waste in landfills occurs. Then, attitudes in resource recovery should allow the recycling of the materials from electronic waste to converting those to new products; therefore, uncommon physical properties from shredding processes are available when bulk ferrites are converted to foil ferrites. This chapter provides a comprehensive study on recyclability of the Mn-Zn ferrites, exploring both structure and conduction properties in foil ferrites to use their nonlinear behavior in functional green devices.
{"title":"Mn-Zn Ferrite as Recycled Material Resource Based on Iron Oxide Suitable to Functional Green Devices","authors":"R. Baca","doi":"10.5772/INTECHOPEN.72418","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.72418","url":null,"abstract":"Today manufacturing stages in electronic device industry of wide-scale production can be restricted due to the high costs resulting from energy consumption, the use of organic solvents, production of hazardous intermediates, and formation of waste products leading to environmental pollution and several biological risks which damage society’s ability to sustain the planet for future generations. As recycled material resource based on iron oxide, the Mn-Zn ferrite is an interesting candidate. In the last decades, this material has been manufactured by using ceramic process technologies to design magnetic devices as components useful in switching mode electronic systems. However, these processing technologies have generated negative environmental impact as emission of toxic gases and higher use of energy resources. The Mn-Zn ferrites employed in consumer electronics deteriorate the earth when its final placement as waste in landfills occurs. Then, attitudes in resource recovery should allow the recycling of the materials from electronic waste to converting those to new products; therefore, uncommon physical properties from shredding processes are available when bulk ferrites are converted to foil ferrites. This chapter provides a comprehensive study on recyclability of the Mn-Zn ferrites, exploring both structure and conduction properties in foil ferrites to use their nonlinear behavior in functional green devices.","PeriodicalId":14641,"journal":{"name":"Iron Ores and Iron Oxide Materials","volume":"35 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2017-12-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81389656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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