A study of the kinetics of bismuth telluride synthesis by an oxide reduction method

Trawiński, Bartosz; Bochentyn, Beata; Łapiński, Marcin; Kusz, B.

doi:10.1016/j.tca.2019.178437

Cited by 13 publications

(2 citation statements)

References 37 publications

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“…The reduction of simple oxides, such as Fe 2 O 3 , NiO, CuO, Co 3 O 4 , and Mn 3 O 4 , has been widely studied. − In contrast, in the case of mixed oxides, there is a lack of understanding. In general, the presence of two metals in the oxide structure can lead to the formation of new intermediate oxides during the reduction.…”

Section: Introductionmentioning

confidence: 99%

In Situ Study of Reduction of Mn_xCo_3–xO₄ Mixed Oxides: The Role of Manganese Content

et al. 2021

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A series of Mn−Co mixed oxides with a gradual variation of the Mn/Co molar ratio were prepared by coprecipitation of cobalt and manganese nitrates. The structure, chemistry, and reducibility of the oxides were studied by X-ray diffraction (XRD), X-ray absorption spectroscopy, X-ray photoelectron spectroscopy (XPS), and temperature-programmed reduction (TPR). It was found that at concentrations of Mn below 37 atom %, a solid solution with a cubic spinel structure is formed. At concentrations above 63 atom %, a solid solution is formed on the basis of a tetragonal spinel, while at concentrations in a range of 37−63 atom %, a two-phase system, which contains tetragonal and cubic oxides, is formed. To elucidate the reduction route of mixed oxides, two approaches were used. The first was based on a gradual change in the chemical composition of Mn−Co oxides, illustrating slow changes in the TPR profiles. The second approach consisted in a combination of in situ XRD and pseudo-in situ XPS techniques, which made it possible to directly determine the structure and chemistry of the oxides under reductive conditions. It was shown that the reduction of Mn−Co mixed oxides proceeds via two stages. During the first stage, (Mn, Co) 3 O 4 is reduced to (Mn, Co)O. During the second stage, the solid solution (Mn, Co)O is transformed into metallic cobalt and MnO. The introduction of manganese cations into the structure of cobalt oxide leads to a decrease in the rate of both reduction stages. However, the influence of additional cations on the second reduction stage is more noticeable. This is due to crystallographic peculiarities of the compounds: the conversion from the initial oxide (Mn, Co) 3 O 4 into the intermediate oxide (Mn, Co)O requires only a small displacement of cations, whereas the formation of metallic cobalt from (Mn, Co)O requires a rearrangement of the entire structure.

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Section: Introductionmentioning

confidence: 99%

In Situ Study of Reduction of Mn_xCo_3–xO₄ Mixed Oxides: The Role of Manganese Content

et al. 2021

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“…Based on TGA, the change in extent of reaction or conversion rate (α), and the non-isothermal rate of the solid-state reaction (dα/dT) can be described by Eqs. (2) and (3), respectively (Vyazovkin et al 2011;Li et al 2020;Trawiński et al 2020;Vyazovkin et al 2014).…”

Section: Kinetic Analysismentioning

confidence: 99%

Non-isothermal reaction mechanism and kinetic analysis for the synthesis of monoclinic lithium zirconate (m-Li2ZrO3) during solid-state reaction

et al. 2021

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Non-isothermal reaction mechanism and kinetic analysis for the synthesis of monoclinic lithium zirconate (m-Li2ZrO3) were investigated by processing of TG-DTA, along with XRD, DLS, and HRTEM. For this purpose, the solid-state reaction of Li2CO3 with ZrO2 was carried out by TG-DTA at different heating rates (10, 20, and 30 °C/min) from room temperature to 1100 °C. The thermal data was used to calculate the kinetic parameters by two types of isoconversional methods: Flynn-Wall-Ozawa (FWO) and Kissinger-Akahira-Sunose (KAS). The reaction mechanism was determined by the model-fitting method, applying the Coats-Redfern (CR) approximation to the different solid-state reaction models. The results confirmed the formation of pure m-Li2ZrO3, consists of semispherical particles of about 490 nm, using a very short reaction time. The average activation energy obtained by FWO and KAS methods were 274.73 and 272.50 kJ/mol, respectively. It was found that the formation of m-Li2ZrO3 from Li2CO3 with ZrO2 is governed by the three-dimensional diffusion mechanism. Based on these results, a microscopic reaction model of the formation of m-Li2ZrO3 was proposed.

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Hierarchical flower-like ZnO–Ag@Cellulose composite with antifouling and antibacterial properties for efficient recovery of tellurium (IV) from wastewater

et al. 2021

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Recovery of the tellurium from wastewater is signi cance for both industrial applications and sustainable development due to the adverse impacts emanating from environmental pollution and strategic values in the photovoltaic industry. Herein, this study presents the recovery of tellurium from wastewater by owerlike structure ZnO-Ag@cellulose (ZAC) composites. For adsorbent preparation, lignocellulose was rst extracted from waste wood debris by an alkaline extraction process. Then, the ower-like structure of ZAC composites were synthesized by a facile one-step hydrothermal method. The obtained materials are conducted under different parameters to investigate tellurium adsorption properties. The results indicate that the tellurium adsorption process is an exothermic reaction and ts well to the Freundlich model. Kinetic data are well described by pseudo-second-order model, indicating ZAC adsorption of tellurium is a chemical process. Besides, as-prepared ZAC exhibited excellent performance for tellurium elimination from wastewater with a maximum removal e ciency of 98.86%. The ZAC also shows outstanding antifouling performance in polluted environment and can still achieve the rate of 94.23% for tellurium. Moreover, the ZAC composite reveals high reusability and stability after six desorption-regeneration cycles. Importantly, the ZAC composite exhibits disinfection performance against E. coli and S. aureus with high killing e ciency. Therefore, this work not only demonstrates ZAC composite is e cient adsorbent with antifouling and antibacterial capability for tellurium recovery, but also provides an effective channel for promising candidates to decontaminate similar pollutants and practical applications of wastewater. Highlights 1. The ZAC composites were fabricated via a facile one-step hydrothermal method.2. The raw materials are extracted from waste wood debris using alkaline extraction process to extract lignocellulose.3. The prepared composite material has high antifouling and antibacterial ability for the adsorption of tellurium (IV). 4. The resulting composite material exhibits excellent performance, with a maximum removal rate of tellurium (IV) was 98.86%.5. The prepared adsorbent has excellent stability and reusable ability to remove tellurium in wastewater.

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A study of the kinetics of bismuth telluride synthesis by an oxide reduction method

Cited by 13 publications

References 37 publications

In Situ Study of Reduction of Mn_xCo_3–xO₄ Mixed Oxides: The Role of Manganese Content

In Situ Study of Reduction of Mn_xCo_3–xO₄ Mixed Oxides: The Role of Manganese Content

Non-isothermal reaction mechanism and kinetic analysis for the synthesis of monoclinic lithium zirconate (m-Li2ZrO3) during solid-state reaction

Hierarchical flower-like ZnO–Ag@Cellulose composite with antifouling and antibacterial properties for efficient recovery of tellurium (IV) from wastewater

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A study of the kinetics of bismuth telluride synthesis by an oxide reduction method

Cited by 13 publications

References 37 publications

In Situ Study of Reduction of MnxCo3–xO4 Mixed Oxides: The Role of Manganese Content

In Situ Study of Reduction of MnxCo3–xO4 Mixed Oxides: The Role of Manganese Content

Non-isothermal reaction mechanism and kinetic analysis for the synthesis of monoclinic lithium zirconate (m-Li2ZrO3) during solid-state reaction

Hierarchical flower-like ZnO–Ag@Cellulose composite with antifouling and antibacterial properties for efficient recovery of tellurium (IV) from wastewater

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In Situ Study of Reduction of Mn_xCo_3–xO₄ Mixed Oxides: The Role of Manganese Content

In Situ Study of Reduction of Mn_xCo_3–xO₄ Mixed Oxides: The Role of Manganese Content