Controlled synthesis, formation mechanism, and carbon oxidation properties of Ho2Cu2O5 nanoplates prepared with a coordination-complex method

摘要

Ho2Cu2O5 nanoplates with perovskite structures were synthesized via a simple solution method (SSM) and a coordination-complex method (CCM) using [ HoCu(3,4-pdc)(2)(OAc)(H2O)(3)]center dot 8H(2)O (L = 3,4-pyridinedicarboxylic acid) as a precursor. The CCM was also performed in an N-2 environment (CCMN) under various calcination conditions. The crystallization processes were characterized using X-ray diffraction, scanning electron microscopy, and high-resolution transmission electron microscopy. Ho2Cu2O5 formed through the diffusion of CuO into Ho2O3 particles. Cu2+ diffused faster than Ho3+ during this process. The initial products of CCMN (along with the thermal decomposition products) were initially laminarized in the N-2 atmosphere, which prevented the growth of CuO particles and decreased the size of the Ho2Cu2O5 particles. The final Ho2Cu2O5 particles from CCMN had a nanoplate morphology with an average thickness of 75 nm. The decomposition of organic molecules and protection from N-2 played important roles in determining the morphology of the resulting Ho2Cu2O5. The catalytic oxidation activity of Ho2Cu2O5 samples for carbon was characterized using a specific surface area measurement and thermogravimetric analysis, which revealed that the samples produced by CCMN had the highest catalytic activity. (C) 2016 Elsevier B.V. All rights reserved.