Surface chemistry modulated introduction of multifunctionality within Co3O4 nanocubes

RSC Advances ◽  
2015 ◽  
Vol 5 (21) ◽  
pp. 16311-16318 ◽  
Author(s):  
Monalisa Pal ◽  
Ashutosh Kumar Singh ◽  
Rupali Rakshit ◽  
Kalyan Mandal

Multifunctional Co3O4 nanocubes, having simultaneously intrinsic multicolor fluorescence and excellent catalytic activity in the degradation of harmful pigments have been developed by facile surface modification with small organic ligand.

2021 ◽  
Author(s):  
Syed Akhil ◽  
V.G.Vasavi Dutt ◽  
Nimai Mishra

In recent years inorganic lead halide perovskite nanocrystals (PNCs) have been used in photocatalytic reactions. The surface chemistry of the PNCs can play an important role in the excited state...


2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Worawat Wattanathana ◽  
Suttipong Wannapaiboon ◽  
Chatchai Veranitisagul ◽  
Navadol Laosiripojana ◽  
Nattamon Koonsaeng ◽  
...  

Palladium-impregnated ceria materials were successfully prepared via an integrated procedure between a metal complex decomposition method and a microwave-assisted wetness impregnation. Firstly, ceria (CeO2) powders were synthesized by thermal decomposition of cerium(III) complexes prepared by using cerium(III) nitrate or cerium(III) chloride as a metal source to form a metal complex precursor with triethanolamine or benzoxazine dimer as an organic ligand. Palladium(II) nitrate was consequently introduced to the preformed ceria materials using wetness impregnation while applying microwave irradiation to assist dispersion of the dopant. The palladium-impregnated ceria materials were obtained by calcination under reduced atmosphere of 10% H2 in He stream at 700°C for 2 h. Characterization of the palladium-impregnated ceria materials reveals the influences of the metal complex precursors on the properties of the obtained materials. Interestingly, the palladium-impregnated ceria prepared from the cerium(III)-benzoxazine dimer complex revealed significantly higher BET specific surface area and higher content of the more active Pdδ+ (δ > 2) species than the materials prepared from cerium(III)-triethanolamine complexes. Consequently, it exhibited the most efficient catalytic activity in the methane steam reforming reaction. By optimization of the metal complex precursors, characteristics of the obtained palladium-impregnated ceria catalysts can be modified and hence influence the catalytic activity.


2018 ◽  
Vol 5 (6) ◽  
pp. 065516 ◽  
Author(s):  
K Sureshkumar ◽  
K Shanthi ◽  
N R Sasirekha ◽  
J Jegan ◽  
S J Sardhar Basha

Surfaces ◽  
2019 ◽  
Vol 2 (2) ◽  
pp. 349-371 ◽  
Author(s):  
Muzammil Iqbal ◽  
Duy Khoe Dinh ◽  
Qasim Abbas ◽  
Muhammad Imran ◽  
Harse Sattar ◽  
...  

Inspired by nature, tunable wettability has attracted a lot of attention in both academia and industry. Various methods of polymer surface tailoring have been studied to control the changes in wetting behavior. Polymers with a precisely controlled wetting behavior in a specific environment are blessed with a wealth of opportunities and potential applications exploitable in biomaterial engineering. Controlled wetting behavior can be obtained by combining surface chemistry and morphology. Plasma assisted polymer surface modification technique has played a significant part to control surface chemistry and morphology, thus improving the surface wetting properties of polymers in many applications. This review focuses on plasma polymerization and investigations regarding surface chemistry, surface wettability and coating kinetics, as well as coating stability. We begin with a brief overview of plasma polymerization; this includes growth mechanisms of plasma polymerization and influence of plasma parameters. Next, surface wettability and theoretical background structures and chemistry of superhydrophobic and superhydrophilic surfaces are discussed. In this review, a summary is made of recent work on tunable wettability by tailoring surface chemistry with physical appearance (i.e. substrate texture). The formation of smart polymer coatings, which adjust their surface wettability according to outside environment, including, pH, light, electric field and temperature, is also discussed. Finally, the applications of tunable wettability and pH responsiveness of polymer coatings in real life are addressed. This review should be of interest to plasma surface science communality particularly focused controlled wettability of smart polymer surfaces.


2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Deniz Rende ◽  
Linda S. Schadler ◽  
Rahmi Ozisik

Polymer nanocomposite foams have received considerable attention because of their potential use in advanced applications such as bone scaffolds, food packaging, and transportation materials due to their low density and enhanced mechanical, thermal, and electrical properties compared to traditional polymer foams. In this study, silica nanofillers were used as nucleating agents and supercritical carbon dioxide as the foaming agent. The use of nanofillers provides an interface upon which CO2nucleates and leads to remarkably low average cell sizes while improving cell density (number of cells per unit volume). In this study, the effect of concentration, the extent of surface modification of silica nanofillers with CO2-philic chemical groups, and supercritical carbon dioxide process conditions on the foam morphology of poly(methyl methacrylate), PMMA, were systematically investigated to shed light on the relative importance of material and process parameters. The silica nanoparticles were chemically modified with tridecafluoro-1,1,2,2-tetrahydrooctyl triethoxysilane leading to three different surface chemistries. The silica concentration was varied from 0.85 to 3.2% (by weight). The supercritical CO2foaming was performed at four different temperatures (40, 65, 75, and 85°C) and between 8.97 and 17.93 MPa. By altering the surface chemistry of the silica nanofiller and manipulating the process conditions, the average cell diameter was decreased from9.62±5.22to1.06±0.32 μm, whereas, the cell density was increased from7.5±0.5×108to4.8±0.3×1011cells/cm3. Our findings indicate that surface modification of silica nanoparticles with CO2-philic surfactants has the strongest effect on foam morphology.


2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
S. Pérez-Rodríguez ◽  
G. García ◽  
L. Calvillo ◽  
V. Celorrio ◽  
E. Pastor ◽  
...  

Vulcan XC-72R-supported Fe catalysts have been synthesised for the electroreduction of CO2to high-added value products. Catalysts were obtained by the polyol method, using ethylene glycol as solvent and reducing agent. Prior to the metal deposition, Vulcan was subjected to different oxidation treatments in order to modify its surface chemistry and study its influence on the physicochemical and electrochemical properties of the catalysts, as well as on the product distribution. The oxidation treatments of the supports modify their textural properties, but do not affect significantly the physicochemical properties of catalysts. However, DEMS studies showed that the carbon support degradation, the distribution of products, and the catalytic activity toward the CO2electroreduction reaction depend significantly on the surface chemistry of the carbon support.


2005 ◽  
Vol 11 (S03) ◽  
pp. 162-165 ◽  
Author(s):  
L. von Mühlen ◽  
R. A. Simao ◽  
C. A. Achete

Surface chemistry and topography of materials are generally preponderant factors in a series of material properties, such as adhesion, wettability, friction and optical properties [1]. Wettability of films, for example, can be altered significantly by modifying its surface roughness and also by incorporating functional groups. Plasma treatment is a powerful and versatile way to modify surface properties of amorphous nitrogen-incorporated carbon thin films (a-C:H(N)) and obtain materials with improved properties, once it is possible to modify the surfaces in a controlled way by specific settings of plasma conditions. [2 - 4]


e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Inês Matos ◽  
Auguste Fernandes ◽  
Rita Catalão ◽  
Ana M. Botelho do Rego ◽  
José R. Ascenso ◽  
...  

AbstractIn this paper we present two different techniques for the preparation of single site heterogeneous catalyst. The first method consists in the impregnation of a solution of the organometallic compound in MCM41. The second method intends to establish the in situ synthesis of the complex within the solid’s pores by the reaction of the organic ligand with the metal cation previously introduced in the support. The direct deposition of the organometallic complex in the support resulted in an active catalyst which gives polyethylene with the same microstructure as the one obtained with the related homogeneous systems. The heterogeneous catalysts obtained by reaction of the ligand with the metal already present in the support showed a lower catalytic activity.


1943 ◽  
Vol 21b (2) ◽  
pp. 21-33
Author(s):  
L. A. Munro ◽  
D. J. Dewar ◽  
S. Gertsman ◽  
G. Monteith

The effect of gel water content on the catalytic activity of alumina in the decomposition of formic acid at 215 and 250 °C. has been investigated. The previous observations on the dehydration of ethyl alcohol to ether and ethylene are paralleled by the results with formic acid. There are two peaks in the curves showing the relation between activity and gel water content. The ratio CO/CO2 changes with gel water content, i.e., the course of the reaction can be altered by surface modification of the catalyst. The gel showing maximum catalytic activity exhibits greatest sorption. The temperature of activation of a hydrous oxide is not as accurate a measure of the catalytic power as the gel water content. X-ray studies of the catalysts show a threefold change in the structure in the 36 to 0% range of water content, but the fibril structure of the gel of maximum activity (5.3% water) is the same as that for minimum activity. An explanation is suggested.


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