Thermal decomposition of nickel acetate tetrahydrate: an integrated study by TGA, QMS and XPS techniques

Jesús, Juan Carlos de; González, Ismael; Quevedo, Angel; Puerta, Tito

doi:10.1016/j.molcata.2004.09.065

Cited by 225 publications

(164 citation statements)

References 22 publications

Supporting

Mentioning

140

Contrasting

Unclassified

Order By: Relevance

“…Decomposition of Au [27], Ni [28] and Ag acetates [29] in an inert atmosphere leads to the formation of metallic nanoparticles, whereas oxidation of Ce(III) into Ce(IV) is usually observed for ceria precursors even in an inert atmosphere [19]. The effect of oxidizing or reducing species produced during decomposition or coming from the furnace atmosphere will depend, in general, on their transport across the sample.…”

Section: Iii4-gas Exchange and Combustion: Reduction Of Cumentioning

confidence: 99%

Thermal analysis of metal organic precursors for functional oxide preparation: Thin films versus powders

et al. 2015

View full text Add to dashboard Cite

The thermal decomposition of several metal organic precursors, used in the preparation of YBa 2 Cu 3 O 7-x superconducting coated conductors (Cu acetate, Cu, Y and Ba trifluoroacetates and Ce propionate) is analyzed by means of several thermoanalytical techniques (TG/DTA, MS and DSC). In all cases, the metal organic precursors deposited as thin films decompose differently than powders from the same precursors. In thin films, decomposition is facilitated by the easier transport of reactive gas from the surrounding atmosphere and by the easier out-diffusion of volatile products. Consequently, films decompose at lower temperature and are more sensitive to the presence of any residual reactive gas in the furnace. Good thermal contact with the substrate is also shown to minimize overheating in films and avoid combustion processes that are otherwise often observed during the thermal decomposition of powders. Finally, the formation and stability of intermediate products towards the oxide formation, such as metal fluorides, differs in films because of the easier gas exchange. With respect to powders, these compounds are much less stable in films, where their decomposition temperature can be lowered by several hundreds of degrees Celsius. While in some cases the behaviour of films can be predicted by analyzing varying masses of precursor powders, this is not always the case. Therefore, thermal analysis carried out on films is recommended to avoid erroneous conclusions about materials preparation drawn from powders.

show abstract

Section: Iii4-gas Exchange and Combustion: Reduction Of Cumentioning

confidence: 99%

Thermal analysis of metal organic precursors for functional oxide preparation: Thin films versus powders

et al. 2015

View full text Add to dashboard Cite

show abstract

“…Segundo JESUS et al [32], esta diferença pode ser um indicativo de que ocorra reações de hidrólise intermediárias na fase gasosa, envolvendo os grupos acetatos durante a desidratação do Ni(CH 3 COO) 2 •4H 2 O.…”

Section: Decomposição Do Acetato De Níquel Tetra-hidratado [Ni(ch3coounclassified

“…O resíduo obtido ao fim da análise térmica foi de 29,7%, valor próximo do teórico de 30,0% para óxido de níquel (NiO). De acordo com JESUS et al [32], tanto o acetato de níquel quanto o hidróxido de níquel, se decompõem em temperaturas distintas, sendo que ambos geram como resíduo NiO. O acetato de níquel decompõe em temperaturas mais baixas, ao passo que hidróxido de níquel decompõe em temperaturas mais elevadas de acordo com as reações 5 e 6 (Tabela 2).…”

Section: Decomposição Do Acetato De Níquel Tetra-hidratado [Ni(ch3coounclassified

Compreendendo as propriedades (estrutural, espectroscópica, colorimétrica e térmica) de sais de níquel

et al. 2018

View full text Add to dashboard Cite

RESUMOSais de níquel (acetato, cloreto e nitrato) são de uso corriqueiro nos laboratórios de síntese inorgânica e orgâ-nica. No processo de obtenção de óxidos, hidróxidos e oxi-hidróxidos de níquel para as mais diversas aplicações (baterias, pigmentos, sensores e eletrocatálise, por exemplo) se faz necessário compreender as características, as propriedades estruturais e eletrônicas, que cada sal precursor pode conferir ao produto final. Como premissa, foi realizado uma avaliação do comportamento estrutural, espectroscópico e térmico de sais de ní-quel. O perfil de difração de raios X (DRX) possibilitou identificar a rede cristalina e seus parâmetros. Dados espectroscópicos (UV-Vis) mostram a similaridade de absorção em solução e as bandas atribuídas de acordo com as transições permitidas e proibidas para o íon hexa(aquo)níquel(II). Porém, os espectros se diferenciam quando se avalia os sólidos por refletância difusa. Fato que possibilita calcular as energias de band gap para cada sal; acetato 2,85 eV, cloreto 2,46 eV e nitrato 2,61 eV. Dados colorimétricos (L*a*b) permitem prever que a intensidade de tom verde diminui na sequência: nitrato > cloreto > acetato. Curvas térmicas (TG/DTA) inferem grau de pureza e quantificam o número de moléculas de água de hidratação, compatíveis com os dados do fornecedor. A análise morfológica (MEV) e estrutural (DRX) das partículas geradas nas curvas térmi-cas permitiram determinar a composição estimada de NiO residual, com maior precisão para o derivado do nitrato de níquel (NiO 1,1 ), com tamanho de partícula da ordem de 0,1 µm, o menor entre os resíduos.Palavras-chave: Sais de níquel, caracterização, espectroscopia, colorimetria. ABSTRACTNickel salts (acetate, chloride and nitrate) are of everyday use in laboratories of inorganic and organic syntheses. In the process of obtaining oxides, hydroxides and oxy-hydroxides of nickel for the most diverse applications (batteries, pigments, sensors and electrocatalysis for example) it is necessary to understand the characteristics, the structural and electronic properties, that each precursor salt can confer to the final product. Premised carry out an assessment of the structural, spectroscopic and thermal behavior of nickel salts. Profile X-ray diffraction (XRD) enabled the identification of the crystal lattice and its parameters. Spectroscopic data (UV-Vis) show the similarity of solution absorption bands assigned in accordance with the permitted and prohibited transitions to hexa(aqua)nickel(II) ion. However, the spectra differ when evaluating the solids by diffuse reflectance. Fact that enables to calculate the band gap energies for each salt; value of 2.85 eV for acetate, 2.46 eV for chloride and 2.61 eV for nitrate. Color data (L*a*b*) can predict the green ton of intensity decreases in the sequence: nitrate> chloride> acetate. Curves thermal (TG-DTA) infer purity and quantify the number of hydration water molecules, consistent with the supplier information. Morphological analysis (SEM) and structural (XRD) of the particles gene...

show abstract

“…Oxygen functionalized MWCNTs were produced by the treatment of MWCNTs with the mixture of concentrated H 2 SO 4 and HNO 3 with the molar ratio of 3:1 [17,18]. 75 ml of H 2 SO 4 (97%) and 25 ml of conc.…”

Section: Oxidation Of Mwcntsmentioning

confidence: 99%

“…In much energy related applications like fuel cells, super capacitors, rechargeable batteries and hydrogen production Ni/CNT nanocomposites have been considered [17][18][19]. Production of metal/metal oxide and CNT composites were attempted by many but no uniform coating of CNTs were obtained.…”

Section: Introductionmentioning

confidence: 99%

Nickel and nickel oxide nanocrystals selectively grafting on multiwalled carbon nanotubes

Prabhu

Rao

Kumari³

et al. 2015

Nano Convergence

View full text Add to dashboard Cite

Nickel and nickel oxide nanocrystals in their pure phase are carefully embellished by a facial method on oxygen-functionalized multi-walled carbon nanotubes (O-MWCNTs) using nickel nitrate (NN) was effectively accomplished for the first time by calcining them in hydrogen, nitrogen and air, respectively, at suitable temperatures. Nickel and nickel oxide nanocrystals impregnated O-MWCNTs were examined for its structure and morphology by various techniques, such as powder X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy and field emission scanning electron microscopy. The nanocrystals on the O-MWCNTs were determined of 15-20 nm size. Decorated nanocrystals on CNT's have potential applications in semiconductor industries.Keywords: MWCNTs; Nickel Nitrate; TEM; XRD; FTIR BackgroundIn the field of nanoscience and nanotechnology carbon nanotubes (CNTs) are the most wanted materials due to their extraordinary properties and potential applications as step forward materials for catalysis, composite reinforcement materials, microelectronics, energy storage, chemical sensors, etc. [1,2]. Mechanical stiffness, field emission properties, excellent thermal and electrical conductivity, high aspect ratio, and the cavities of CNTs fetches them the advantage in their applications [3][4][5][6]. CNTs are chemically inert and insoluble in the most solvents thus hampering their application and manipulation in various possible fields. Surface functionalization of CNTs is one way of overcoming these difficulties. This method has established a wide range of applications in the fields of composite materials, sensors and catalysis [7][8][9][10].By the application of oxidation reagents like HNO 3 or a mixture of H 2 SO 4 /HNO 3 can disjoint the aromatic ring system of CNTs [11]. As a result carboxylic (−COOH), carbonyl (−CO) and hydroxylic (−OH) can be present on the nanotubes as they are required to anchor guest species such as metal ions to the CNT [12,13]. The wetting characteristics and reactivity of nanotubes are modified thus enriching their properties. It guides us to the subject of interfacial bonding between the metal atoms and defective and oxidized CNTs to ensure excellent mechanical performances for the CNT-reinforced metal-matrix composites.The stable CNT-metal structures are potential engineering materials in the areas of CNT devices for different spintronics applications and CNT metal-matrix composites [14][15][16]. In much energy related applications like fuel cells, super capacitors, rechargeable batteries and hydrogen production Ni/CNT nanocomposites have been considered [17][18][19]. Production of metal/metal oxide and CNT composites were attempted by many but no uniform coating of CNTs were obtained. However some worked with polymers to assist the process of decorating of metal/metal oxides [20,21]. For example, Tang et al. [20] reported that Ni decorated MWCNTs were modified with poly (acrylic acid) for hydrogenation of α, β-unsaturated aldehyde. Similarly homogeneous e...

show abstract

Thermal decomposition of nickel acetate tetrahydrate: an integrated study by TGA, QMS and XPS techniques

Cited by 225 publications

References 22 publications

Thermal analysis of metal organic precursors for functional oxide preparation: Thin films versus powders

Thermal analysis of metal organic precursors for functional oxide preparation: Thin films versus powders

Compreendendo as propriedades (estrutural, espectroscópica, colorimétrica e térmica) de sais de níquel

Nickel and nickel oxide nanocrystals selectively grafting on multiwalled carbon nanotubes

Contact Info

Product

Resources

About