Simple and fast method for determination of preferred crystallographic orientation of nanoparticles: A study on ZnS/kaolinite nanocomposite

Highlights: • Preferred crystallographic orientation (PCO) of ZnS on kaolinite (KLT) is studied. • PCO in real ZnS/KLT nanocomposite is analyzed using HRTEM. • PCO is predicted by molecular modeling (MM) and structure compatibility (SC) methods. • Both MM and SC predictions of PCO agree well with the HRTEM analysis. • For prediction of the PCO, the MM can be replaced by simpler and faster SC method. Crystallographic orientation of nanoparticles anchored on surface of solid crystalline matrix plays an important role in the resulting activity (e.g. the catalytic activity) of such structured nanocomposites. Possibility to predict the crystallographic orientation can thus be advantageous in many areas of materials science. This study presents a simple method of such prediction by determining the structure compatibility of two crystal structures based on the average number of pairs of overlapping atoms calculated from the mutual rotation of two (h k l) planes: one plane belonging to the nanoparticle crystal structure, the second one belonging to the matrix crystal structure. In this work, the structure compatibility of photocatalytic ZnS nanoparticles and tetrahedral kaolinite surface was studied. Results were compared with molecular simulations and with the high-resolution transmission electron microscopy analysis performed on a sample of the real ZnS/kaolinite nanocomposite. All three approaches led to identical result: the same preferred crystallographic orientation of ZnS on the tetrahedral surface of kaolinite was found. The method of determining structure compatibility is the fastest of the three approaches used, and thus appears to be very suitable for the purpose of predicting the preferred crystallographic orientation.