The massive production of nanostructures with controlled features and high surface area is a challenging and timely task in view of developing effective materials for sensing and catalysis. Herein, functional ZnO nanostructures, named microflowers (MFs) have been prepared by a facile and rapid chemical bath deposition. ZnO MFs show an intriguing sheets-composed spheroidal shape, with diameters in the range 0.2–2.5 µm, whose formation is achieved by a complexing action by F in an aqueous solution of zinc nitrate hexahydrate and hexamethylenetetramine. The evolution of the physical and structural properties of the material, following post-deposition thermal annealing, has been investigated by scanning electron microscopy (SEM), energy dispersive X-ray analyses (EDX), photoluminescence (PL) and X-ray diffraction (XRD) techniques. The effectiveness of ZnO MFs in UV detection has also been tested to account for the potentiality of these nanostructures.

The conservation of the historic stone heritage has great importance when this material characterizes the image of a city, as it happens in Syracuse (Sicily). Its historical buildings are afflicted by a heavy state of deterioration due to the particular microclimate, to pollution and to neglect endured over time. This article reports the investigations made on limestone samples from historic façades of the city and from the neighboring quarries still in operation, in order to understand the petrographic typology, the reaction to the degradation over time, the possible maintenance and recovery interventions, and the correct applications in buildings of new construction. For this aim, bulk and surface analysis have been made both on the quarry materials and on the corresponding aged materials. It is therefore possible to define the types of rock most suitable for the use in contemporary architecture guaranteeing criteria of perfect biocompatibility. In this way a natural material can be employed in traditional and innovative uses and ensure both the sustainability of the interventions and the continuity of a consolidated tradition.