In-situ microcalorimetry study on thermodynamic functions of Cu 2 O nanocubes

Micro & nano letters

article

Zijun He¹  Huanfeng Tang¹  Zaiyin Huang² 

[1] Department of Chemistry and Chemical Engineering, Guangxi University for Nationalities;Key Laboratory of Forest Chemistry and Engineering, Key Laboratory of Guangxi Colleges and Universities for Food Safety and Pharmaceutical Analytical Chemistry

关键词: calorimetry;    X-ray photoelectron spectra;    particle size;    scanning electron microscopy;    entropy;    copper compounds;    free energy;    X-ray diffraction;    nanofabrication;    enthalpy;    surface energy;    nanoparticles;    semiconductor materials;    semiconductor growth;    liquid phase reduction method;    X-ray diffraction;    X-ray photoelectron spectroscopy;    thermodynamic principles;    transition state theory;    particle size;    conventional thermodynamic functions;    molar surface Gibbs energy;    molar surface enthalpy;    molar surface entropy;    surface physics;    cuprous oxide nanocubes;    scanning electron microscopy;    in-situ microcalorimetry;    surface thermodynamic functions;    thermodynamic models;    standard molar Gibbs energy;    size 40.0 nm to 120.0 nm;    Cu2O;   

DOI  :  10.1049/mnl.2019.0233

学科分类：计算机科学（综合）

来源: Wiley

【 摘 要 】

Four different sizes of cuprous oxides (Cu 2 O) nanocubes in the range of 40–120 nm were synthesised by liquid phase reduction method. The morphology, size, and structure of synthesised Cu 2 O nanocubes were characterised by scanning electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. In-situ microcalorimetry was used to calculate the conventional and surface thermodynamic functions of Cu 2 O nanocubes by combining thermodynamic principles and transition state theory. The effect of particle size on conventional thermodynamic functions and surface thermodynamic functions were investigated and analysed, whose results were supported by the established thermodynamic models. Results showed that both the standard molar enthalpy of formation and the standard molar entropy of formation were increased with decreasing particle size, while the standard molar Gibbs energy of formation decreased. Also, the molar surface Gibbs energy, molar surface enthalpy, and molar surface entropy grew with the reduction of particle size, which correlated well with the models. Such a property is of scientific significance for enriching and developing disciplines such as surface physics and surface thermodynamics.

【 授权许可】

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