Decomposition processes of nickel hydroxide

Isothermal decomposition kinetics of nickel (II) hydroxide powder

“…Hazell and Irving proposed that adsorbed water masks continued reaction measured by mass change above 60% conversion based upon IR absorption data [20]. Logvinenko et al explained the slowing of the reaction as the result of trapped water within the lattice and steric hindrance of remaining residual OHgroups [23]. Based upon our results and other literature studies, nickel hydroxide certainly appears to be a substance that remains attached in some form to its product water, which then tends to suppress continued thermal decomposition.…”

“…Logvinenko et al [23] performed non-isothermal kinetic studies (heating rates of 5-20°C/min) under helium flow utilizing the model-free Ozawa-Flynn-Wall technique. They found that dehydration of surface water occurred below 157°C, and thus limited their kinetic study to temperatures above 157°C.…”

Paraotwayite-type α-Ni(OH)2 Nanowires: Structural, Optical, and Electrochemical Properties

“…Figure reports the thermogravimetric analysis (TGA) results of the as-synthesized Paraotwayite-type α-Ni(OH) 2 nanowires, revealing clearly the characteristic stepwise weight loss due to the dehydration and decomposition reactions. , The total weight loss up to 800 °C is about 33.5%, which consists of three distinguished contributions: the first weight loss (∼4%) from 30 °C to about 200 °C can be attributed to the free water molecules that are absorbed on the surface or trapped in the interlayer region; from 200 °C to about 400 °C, the second weight loss is about 14.0%, which is mainly due to the dehydroxylation of the Ni(OH) 2 principle layers; and the third weight loss, from 400 °C to about 800 °C, is about 14.5%, which can be attributed to the decomposition of the sulfate anions from the interlayer space. The involved dehydration and decomposition processes can be understood as follows: Ni false( OH false) 1.64 false( SO 4 false) 0.18 normal· 0.3 normalH 2 normalO → 30 normal− 200 0.25em °C Ni ( OH ) 1.64 ( SO 4 ) 0.18 goodbreak+ 0.3 normalH 2 normalO Ni false( OH false) 1.64 false( SO 4 false) 0.18 → 200 normal− 400 0.25em °C 0.18 NiSO 4 + 0.82 NiO + 0.82 normalH 2 normalO …”

“…It indicates that the Paraotwayitetype α-Ni(OH) 2 can transform into NiO by electron-beam irradiation under high-vacuum conditions due to the rapid dehydration/decomposition of Ni(OH) 2 . 6,36 Figure 5 reports the thermogravimetric analysis (TGA) results of the as-synthesized Paraotwayite-type α-Ni(OH) 2 nanowires, revealing clearly the characteristic stepwise weight loss due to the dehydration and decomposition reactions. 6,36 The total weight loss up to 800 °C is about 33.5%, which consists of three distinguished contributions: the first weight loss (∼4%) from 30 °C to about 200 °C can be attributed to the free water molecules that are absorbed on the surface or trapped in the interlayer region; from 200 °C to about 400 °C, the second weight loss is about 14.0%, which is mainly due to the dehydroxylation of the Ni(OH) 2 principle layers; and the third weight loss, from 400 °C to about 800 °C, is about 14.5%, which can be attributed to the decomposition of the sulfate anions from the interlayer space.…”

Synthesis, characterization and nonisothermal decomposition kinetics of La2(CO3)3·3.4H2O

“…To improve the product quality of lanthanum carbonate hydrates and La 2 O 3 , it is very important to clarify the decomposition mechanism of La 2 (CO 3 ) 3 to La 2 O 2 CO 3 based on conventional thermal analysis. The study of the decomposition kinetics can help to understand the complexity of the formation of oxide structured materials [13]. The investigation of conversion mechanism allows not only the quantitative precipitation of cations in solution, but also the control of some physicochemical properties of the resulting oxide via the thermal treatment (morphology, surface area, impurities, etc.)…”