scholarly journals Hydrothermal synthesis, characterization and enhanced photocatalytic activity and toxicity studies of a rhombohedral Fe2O3 nanomaterial

RSC Advances ◽  
2019 ◽  
Vol 9 (43) ◽  
pp. 25158-25169 ◽  
Author(s):  
Mavinakere Ramesh Abhilash ◽  
Akshatha Gangadhar ◽  
Jagadish Krishnegowda ◽  
Mahendra Chikkamadaiah ◽  
Shivanna Srikantaswamy
Keyword(s):  
Photocatalytic Activity ◽  
Hydrothermal Synthesis ◽  
Metal Oxide ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Hydrothermal Route ◽  
Toxicity Studies ◽  
Facile Hydrothermal Route

The present investigation focuses on the synthesis of metal oxide nanoparticles (MONPs) via a facile hydrothermal route.

Rapid and continuous hydrothermal synthesis of metal and metal oxide nanoparticles with a microtube-reactor at 523 K and 30 MPa

2008 ◽  
Vol 62 (19) ◽  
pp. 3471-3473 ◽  
Author(s):  
Akiko Kawai-Nakamura ◽  
Toshiyuki Sato ◽  
Kiwamu Sue ◽  
Satoshi Tanaka ◽  
Kazunori Saitoh ◽  
...  
Keyword(s):  
Hydrothermal Synthesis ◽  
Metal Oxide ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles

scholarly journals Synthesis of New Composites of Inorganic Polymers (Geopolymers) with Metal Oxide Nanoparticles and their Photodegradation of Organic Pollutants

2021 ◽  
Author(s):  
◽  
Mahroo Falah
Keyword(s):  
Photocatalytic Activity ◽  
Metal Oxide ◽  
Organic Pollutants ◽  
Metal Oxide Nanoparticles ◽  
Inorganic Polymer ◽  
Oxide Nanoparticles ◽  
Inorganic Polymers ◽  
Oxide Component ◽  
Geopolymer Matrix ◽  
Geopolymer Composites

<p>This thesis describes the development and performance of novel photocatalytic inorganic polymer (geopolymer) composites for photodegradation of environmentally harmful organic materials. Nanometer-sized cubic cuprous oxide nanoparticles and spherical Cu₂O/TiO₂ nano-heterostructures were synthesized via a precipitation method and then added to a metakaolinite-based geopolymer matrix prior to curing at ambient temperature.  The morphology of the homogeneous oxide nanoparticle dispersion within the geopolymer matrix was demonstrated by SEM/EDS and HRTEM. FTIR spectroscopy confirmed the formation of a well-reacted geopolymer matrix that was unaffected by the insertion of the Cu₂O and Cu₂O/TiO₂ nanoparticles. The structures of these new composites were determined by ²⁷Al and ²⁹Si MAS NMR spectroscopy. ⁶³Cu NQR spectroscopy and XRD confirmed that the metal oxide nanoparticles are unchanged by their incorporation in the geopolymer composite and after the photodegradation reactions. The nitrogen adsorption-desorption isotherms were determined, providing information about the specific surface areas and total pore volumes of the composites. The action of the composites in the adsorption and photocatalytic destruction of the model organic compound MB was determined under dark and UV illumination conditions. Experiments in dark conditions and under UV irradiation showed that these materials efficiently remove a model organic pollutant (MB dye) from solution by a dual process of adsorption on the geopolymer matrix, and photodecomposition of the dye without destroying the geopolymer structure. The adsorption kinetics of the dye are best described by a pseudo first-order model and the adsorption process by Langmuir-Freundlich isotherms.  In a novel extension of this research, the metakaolinite-based geopolymer matrix was modified with a surfactant (cetyltrimethylammonium bromide, CTAB), exploiting the cation exchange capacity of the geopolymers structure. The nano oxide composites were synthesised by adding different amounts of as-prepared metal oxide nanoparticles to the modified geoplymer to produce a hydrophobic photocatalyst composite with improved photocatalytic activity arising from the dispersion of the metal oxide nanoparticles in the external surfaces and interlayers of the geopolymer matrix. This method has the advantage of producing geopolymer composites with a stable pH which are more suitable for dye degradation studies.  At concentrations >20 wt%, the photo-oxide component decreases the adsorption rate by blocking the active adsorption sites of the geopolymer. Under UV radiation, the composites remove the MB by a combination of adsorption and photodegradation, without deterioration of the geopolymer structure or the photoactive metal oxide component.  In addition these studies show that the metal oxide-geopolymer nano composites have significantly improved photocatalytic activity compared with the oxide nanoparticles alone, because of the unique properties of these inorganic polymers. These results demonstrate that composites of nanosized Cu₂O particles and photoreactive TiO₂ in an aluminosilicate inorganic polymer matrix constitute new and novel materials with potential environmental protection applications to efficiently remove organic pollutants from water or the atmosphere.</p>

scholarly journals Photocatalytic Degradation with Green Synthesized Metal Oxide Nanoparticles – A Mini Review

2021 ◽  
Vol 2 (1) ◽  
pp. 70-81
Author(s):  
Eleen Dayana Mohamed Isa ◽  
Kamyar Shameli ◽  
Nurfatehah Wahyuny Che Jusoh ◽  
Siti Nur Amalina Mohamad Sukri ◽  
Nur’Afini Ismail
Keyword(s):  
Water Pollution ◽  
Photocatalytic Activity ◽  
Metal Oxide ◽  
Green Synthesis ◽  
Metal Oxide Nanoparticles ◽  
Treatment Method ◽  
Oxide Nanoparticles ◽  
Photocatalytic Process ◽  
Promising Solution ◽  
Environmentally Friendly Process

Water pollution is one of the major problems faced by mankind worldwide. With the increase of populations and urbanization, the natural water resources are under great threat due to the release of untreated effluent. An alternative treatment method, photocatalysis, emerged as a promising solution. Photocatalysis process utilizes photosensitive catalyst to degrade the pollutant and one of the most common catalyst being used is metal oxide. To increase the photocatalytic activity, nanosized metal oxide being used instead of its bulk form. In these recent years, metal oxide nanoparticles production has been shifted towards a more environmentally friendly process which is also commonly known as green synthesis. In this review, we discussed on the photocatalytic process and production via green synthesis of common metal oxide nanoparticles being used as photocatalyst.

scholarly journals Synthesis of New Composites of Inorganic Polymers (Geopolymers) with Metal Oxide Nanoparticles and their Photodegradation of Organic Pollutants

2021 ◽  
Author(s):  
◽  
Mahroo Falah
Keyword(s):  
Photocatalytic Activity ◽  
Metal Oxide ◽  
Organic Pollutants ◽  
Metal Oxide Nanoparticles ◽  
Inorganic Polymer ◽  
Oxide Nanoparticles ◽  
Inorganic Polymers ◽  
Oxide Component ◽  
Geopolymer Matrix ◽  
Geopolymer Composites

<p>This thesis describes the development and performance of novel photocatalytic inorganic polymer (geopolymer) composites for photodegradation of environmentally harmful organic materials. Nanometer-sized cubic cuprous oxide nanoparticles and spherical Cu₂O/TiO₂ nano-heterostructures were synthesized via a precipitation method and then added to a metakaolinite-based geopolymer matrix prior to curing at ambient temperature.  The morphology of the homogeneous oxide nanoparticle dispersion within the geopolymer matrix was demonstrated by SEM/EDS and HRTEM. FTIR spectroscopy confirmed the formation of a well-reacted geopolymer matrix that was unaffected by the insertion of the Cu₂O and Cu₂O/TiO₂ nanoparticles. The structures of these new composites were determined by ²⁷Al and ²⁹Si MAS NMR spectroscopy. ⁶³Cu NQR spectroscopy and XRD confirmed that the metal oxide nanoparticles are unchanged by their incorporation in the geopolymer composite and after the photodegradation reactions. The nitrogen adsorption-desorption isotherms were determined, providing information about the specific surface areas and total pore volumes of the composites. The action of the composites in the adsorption and photocatalytic destruction of the model organic compound MB was determined under dark and UV illumination conditions. Experiments in dark conditions and under UV irradiation showed that these materials efficiently remove a model organic pollutant (MB dye) from solution by a dual process of adsorption on the geopolymer matrix, and photodecomposition of the dye without destroying the geopolymer structure. The adsorption kinetics of the dye are best described by a pseudo first-order model and the adsorption process by Langmuir-Freundlich isotherms.  In a novel extension of this research, the metakaolinite-based geopolymer matrix was modified with a surfactant (cetyltrimethylammonium bromide, CTAB), exploiting the cation exchange capacity of the geopolymers structure. The nano oxide composites were synthesised by adding different amounts of as-prepared metal oxide nanoparticles to the modified geoplymer to produce a hydrophobic photocatalyst composite with improved photocatalytic activity arising from the dispersion of the metal oxide nanoparticles in the external surfaces and interlayers of the geopolymer matrix. This method has the advantage of producing geopolymer composites with a stable pH which are more suitable for dye degradation studies.  At concentrations >20 wt%, the photo-oxide component decreases the adsorption rate by blocking the active adsorption sites of the geopolymer. Under UV radiation, the composites remove the MB by a combination of adsorption and photodegradation, without deterioration of the geopolymer structure or the photoactive metal oxide component.  In addition these studies show that the metal oxide-geopolymer nano composites have significantly improved photocatalytic activity compared with the oxide nanoparticles alone, because of the unique properties of these inorganic polymers. These results demonstrate that composites of nanosized Cu₂O particles and photoreactive TiO₂ in an aluminosilicate inorganic polymer matrix constitute new and novel materials with potential environmental protection applications to efficiently remove organic pollutants from water or the atmosphere.</p>

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