A XRD Study of the CuAl Layered Double Hydroxide Synthesis Evolution

Abstract

It is a challenge to determine the active part of a solid phase in chemical process when the purity of the aforesaid is not sufficient and could jeopardize the solid real applications. CuAl LDH phase has been obtained with low percentage of impurities and the intention to use it as photoreduction or photoxidation catalyst and /or templating agent in the design of nanohybrid composites photocatalysts, for CO2 storage that could facilitate its later abatement and/or highly efficient semiconductor material. A set of synthesis were implemented with a mixture of Cu(NO3)22.5H2O and Al(NO3)3.9H2O with Na2CO3 and NaOH using coprecipitation at variable pH. Keeping constant a low CO32-/Cu2+ + Al3+ fraction in all sets, constant basic pH and ageing time (96h) with slight variations in T, resulted in mixed phases of malachite, CuAl LDH and traces of Cu(OH)2. At basic pH and T with different ageing time, similar XRD patterns were measured with noticeable differences, though. When the carbonate ratio, ageing time, and pH were constant (7.50, 96 h, 9.24), modest changes in T generated key dissimilitude in the diffractograms. The resulting band gap energy of this LDH coincided with the visible spectral region energy. A more precise tuning of variables has led to a high degree of optimization of the CuAl LDH and further contributes to comprehend how varied synthesis conditions influence this metastable hydrotalcite Obtention.