Room temperature Mg reduction of TiO2: formation mechanism and application in photocatalysis

2019 ◽  
Vol 55 (53) ◽  
pp. 7675-7678 ◽  
Author(s):  
Di Zu ◽  
Zhongfei Xu ◽  
Ao Zhang ◽  
Haiyang Wang ◽  
Hehe Wei ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Metal Oxides ◽  
Formation Mechanism ◽  
Room Temperature ◽  
Oxygen Vacancies ◽  
Oxide Structure

A Mg/HCl infiltrated metal oxide structure was designed as a facile approach for implanting oxygen vacancies and H atoms into metal oxides.

Facile Botanical Templating Strategies for the Growth of Porous Metal Oxides in Artificial Leaf-Like Macroscale Structures for Potential Use in Energy Related Catalysis

2013 ◽  
Vol 1539 ◽  
Author(s):  
Edward G. Gillan
Keyword(s):  
Metal Oxide ◽  
Metal Oxides ◽  
Room Temperature ◽  
Sol Gel ◽  
Porous Metal ◽  
Internal Structures ◽  
Battery Systems ◽  
Porous Metal Oxides ◽  
Interconnected Pore ◽  
Potential Use

ABSTRACTA major challenge in utilizing living botanical materials, such as cellular leaf structures, as templates is that they are filled with water and conventional dehydration strategies often collapse or degrade the intricate botanical structure. This restricts the ability to introduce water reactive precursors into such structures. We have developed a room-temperature chemical method using acidified 2,2-dimethoxypropane to dehydrate water-rich botanical materials (e.g., fern leaves and water-rich jade succulents). This mild dehydration process leaves much of the porous cellular leaf structure intact even with ∼90% mass loss. These chemically dehydrated templates have been utilized in the growth of porous and ordered leaf replicate structures consisting of TiO2 and SiO2 via sol-gel precursor impregnation methods. These white metal oxide products exhibit external and internal structures that look very similar to their original templates, but are shrunken intact versions of the original. This paper details the chemical procedures that enable one to effectively use sensitive botanical templates in metal oxide growth. The physical and structural properties of several dried porous templates and macroporous anatase TiO2 and amorphous or crystoballite SiO2 products will be described. Recent efforts to use these botanical templates to produce other porous metal oxides (e.g., Co3O4, NiO, and CuO) using both halide and acetate precursor impregnation strategies are noted. Porous metal oxides with interconnected pore walls may have use in electrochemical energy storage systems, including in photocatalytic, photovoltaic or battery systems.

scholarly journals Advances in designs and mechanisms of semiconducting metal oxide nanostructures for high-precision gas sensors operated at room temperature

2019 ◽  
Vol 6 (3) ◽  
pp. 470-506 ◽  
Author(s):  
Zhijie Li ◽  
Hao Li ◽  
Zhonglin Wu ◽  
Mingkui Wang ◽  
Jingting Luo ◽  
...  
Keyword(s):  
Metal Oxide ◽  
Metal Oxides ◽  
Gas Sensors ◽  
Room Temperature ◽  
Comprehensive Review ◽  
Sensor Applications ◽  
Oxide Nanostructures ◽  
Metal Oxide Nanostructures ◽  
Semiconducting Metal Oxides ◽  
Semiconducting Metal Oxide

A comprehensive review on designs and mechanisms of semiconducting metal oxides with various nanostructures for room-temperature gas sensor applications.

Room temperature gas sensor based on porous silicon/metal oxide structure

2007 ◽  
Vol 4 (6) ◽  
pp. 2059-2062 ◽  
Author(s):  
V. M. Arakelyan ◽  
Kh. S. Martirosyan ◽  
V. E. Galstyan ◽  
G. E. Shahnazaryan ◽  
V. M. Aroutiounian
Keyword(s):  
Porous Silicon ◽  
Metal Oxide ◽  
Gas Sensor ◽  
Room Temperature ◽  
Oxide Structure

Metal-oxide based ammonia gas sensors: A review

2020 ◽  
Vol 10 ◽  
Author(s):  
Priya Gupta ◽  
Savita Maurya ◽  
Narendra Kumar Pandey ◽  
Vernica Verma
Keyword(s):  
Metal Oxide ◽  
Metal Oxides ◽  
Gas Sensor ◽  
Gas Sensors ◽  
Review Paper ◽  
Gas Sensing ◽  
Gas Sensitivity ◽  
Ammonia Gas ◽  
Ammonia Sensing ◽  
Ammonia Gas Sensors

: This review paper encompasses a study of metal-oxide and their composite based gas sensors used for the detection of ammonia (NH3) gas. Metal-oxide has come into view as an encouraging choice in the gas sensor industry. This review paper focuses on the ammonia sensing principle of the metal oxides. It also includes various approaches adopted for increasing the gas sensitivity of metal-oxide sensors. Increasing the sensitivity of the ammonia gas sensor includes size effects and doping by metal or other metal oxides which will change the microstructure and morphology of the metal oxides. Different parameters that affect the performances like sensitivity, stability, and selectivity of gas sensors are discussed in this paper. Performances of the most operated metal oxides with strengths and limitations in ammonia gas sensing application are reviewed. The challenges for the development of high sensitive and selective ammonia gas sensor are also discussed.

scholarly journals Thermochemical Energy Storage Performance Analysis of (Fe,Co,Mn)Ox Mixed Metal Oxides

Catalysts ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 362
Author(s):  
Yabibal Getahun Dessie ◽  
Qi Hong ◽  
Bachirou Guene Lougou ◽  
Juqi Zhang ◽  
Boshu Jiang ◽  
...  
Keyword(s):  
Energy Storage ◽  
Metal Oxide ◽  
Metal Oxides ◽  
Redox Reaction ◽  
Gas Flow ◽  
Oxygen Exchange ◽  
Engineering Industry ◽  
Oxide Material ◽  
Oxide Materials ◽  
Uptake Ratio

Metal oxide materials are known for their ability to store thermochemical energy through reversible redox reactions. Metal oxides provide a new category of materials with exceptional performance in terms of thermochemical energy storage, reaction stability and oxygen-exchange and uptake capabilities. However, these characteristics are predicated on the right combination of the metal oxide candidates. In this study, metal oxide materials consisting of pure oxides, like cobalt(II) oxide, manganese(II) oxide, and iron(II, III) oxide (Fe3O4), and mixed oxides, such as (100 wt.% CoO, 100 wt.% Fe3O4, 100 wt.% CoO, 25 wt.% MnO + 75 wt.% CoO, 75 wt.% MnO + 25 wt.% CoO) and 50 wt.% MnO + 50.wt.% CoO), which was subjected to a two-cycle redox reaction, was proposed. The various mixtures of metal oxide catalysts proposed were investigated through the thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), energy dispersive X-ray (EDS), and scanning electron microscopy (SEM) analyses. The effect of argon (Ar) and oxygen (O2) at different gas flow rates (20, 30, and 50 mL/min) and temperature at thermal charging step and thermal discharging step (30–1400 °C) during the redox reaction were investigated. It was revealed that on the overall, 50 wt.% MnO + 50 wt.% CoO oxide had the most stable thermal stability and oxygen exchange to uptake ratio (0.83 and 0.99 at first and second redox reaction cycles, respectively). In addition, 30 mL/min Ar–20 mL/min O2 gas flow rate further increased the proposed (Fe,Co,Mn)Ox mixed oxide catalyst’s cyclic stability and oxygen uptake ratio. SEM revealed that the proposed (Fe,Co,Mn)Ox material had a smooth surface and consisted of polygonal-shaped structures. Thus, the proposed metallic oxide material can effectively be utilized for high-density thermochemical energy storage purposes. This study is of relevance to the power engineering industry and academia.

Graphene-Induced Growth of Co3O4 Nanoplates with Modulable Oxygen Vacancies for Improved OER Properties

CrystEngComm ◽  
2021 ◽  
Author(s):  
Xinheng Li ◽  
Lei Qi ◽  
Mei Wang
Keyword(s):  
Transition Metal ◽  
Metal Oxide ◽  
Hydrothermal Treatment ◽  
Oxygen Evolution ◽  
Oxygen Evolution Reaction ◽  
Oxygen Vacancies ◽  
Transition Metal Oxide ◽  
Oxide Hydroxide

Transition metal oxide/ hydroxide is intensively studied for oxygen evolution reaction (OER). Herein, graphene-induced growth of Co3O4 nanoplates with modulable oxygen vacancies via hydrothermal treatment is reported. With the increase...

Prebiotic studies on the interaction of zirconia nanoparticles and ribose nucleotides and their role in chemical evolution

2021 ◽  
Vol 20 (2) ◽  
pp. 142-149
Author(s):  
Avnish Kumar Arora ◽  
Pankaj Kumar
Keyword(s):  
Electron Microscopy ◽  
Metal Oxide ◽  
Metal Oxides ◽  
Chemical Evolution ◽  
Ribonucleic Acid ◽  
Zirconium Oxide ◽  
Origins Of Life ◽  
Neutral Ph ◽  
Interaction Studies

AbstractStudies on the interaction of biomolecules with inorganic compounds, mainly mineral surfaces, are of great concern in identifying their role in chemical evolution and origins of life. Metal oxides are the major constituents of earth and earth-like planets. Hence, studies on the interaction of biomolecules with these minerals are the point of concern for the study of the emergence of life on different planets. Zirconium oxide is one of the metal oxides present in earth's crust as it is a part of several types of rocks found in sandy areas such as beaches and riverbeds, e.g. pebbles of baddeleyite. Different metal oxides have been studied for their role in chemical evolution but no studies have been reported about the role of zirconium oxide in chemical evolution and origins of life. Therefore, studies were carried out on the interaction of ribonucleic acid constituents, 5′-CMP (cytidine monophosphate), 5′-UMP (uridine monophosphate), 5′-GMP (guanosine monophosphate) and 5′-AMP (adenosine monophosphate), with zirconium oxide. Synthesized zirconium oxide particles were characterized by using vibrating sample magnetometer, X-Ray Diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy. Zirconia particles were in the nanometre range, from 14 to 27 nm. The interaction of zirconium oxide with ribonucleic acid constituents was performed in the concentration range of 5 × 10−5–300 × 10−5 M. Interaction studies were carried out in three mediums; acidic (pH 4.0), neutral (pH 7.0) and basic (pH 9.0). At neutral pH, maximum interaction was observed. The interaction of zirconium oxide with 5′-UMP was 49.45% and with 5′-CMP 67.98%, while with others it was in between. Interaction studies were Langmurian in nature. Xm and KL values were calculated. Infrared spectral studies of ribonucleotides, metal oxide and ribonucleotide–metal oxide adducts were carried out to find out the interactive sites. It was observed that the nitrogen base and phosphate moiety of ribonucleotides interact with the positive charge surface of metal oxide. SEM was also carried out to study the adsorption. The results of the present study favour the important role of zirconium oxide in concentrating the organic molecules from their dilute aqueous solutions in primeval seas.

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