Recently, a new class of materials with very high porosity and ultra-lightweight, namely, semiconductor aero-materials, has attracted the attention of many researchers. Semiconductor aero-materials, due to their special properties, can be used in the development of devices applied in biomedical, electronics, optoelectronic, energy conversion and storage, sensors, biosensors, catalysis, automotive, and aeronautic industries. Although aero-materials and aerogels are similar, different methods of obtaining them are used. Aerogels are synthesized from organic, inorganic, or hybrid precursors, the main characteristic being that they are gel-like solids with a high air content (99.9%) in the structure. Thus, three-dimensional (3D) interconnected porous network chains are formed, resulting in light solid-state structures with very high porosity due to the large number of air pores in the network. On the other hand, to obtain aero-materials with controlled properties such as morphology, shape, or the formation of 3D hollow structures, sacrificial templates are used. Thus, sacrificial structures (which can be easily removed) can be obtained depending on the morphology of the 3D structure to be obtained. Therefore, this review paper offers a comprehensive coverage of the synthesis methods of different types of semiconductor aero-materials that use ZnO tetrapod, ZnO(T), as a sacrificial template, related to the present and future perspectives. These ZnO(T) sacrificial substrates offer several advantages, including diverse synthesis processes and easy removal methods that occur simultaneously with the growth of the desired aero-materials.

Electrochemical impedance spectroscopy (EIS) provides a powerful means of probing interfacial and charge-transport phenomena in semiconductor electrodes, yet interpretation becomes increasingly difficult when applied to nanostructured materials. Semiconductor nanowires, nanotubes, and porous films exhibit high surface areas, heterogeneous morphologies, and defect-rich interfaces, all of which modify their impedance response. Theoretical principles regarding EIS behavior in such systems are presented, beginning with semiconductor–electrolyte junction formation, space-charge layer development, band bending and the influence of surface states. Key elements of equivalentcircuit descriptions are examined, including double-layer capacitance, charge-transfer resistance and diffusion-related impedance contributions. Special emphasis is placed on constant-phase elements and distributed models required to capture non-ideal capacitive behavior characteristic of nanoscale electrodes. Common challenges in spectral interpretation, such as overlapping time constants, non-uniform current distribution and deviations from classical Randles-type responses, are summarized within a unified theoretical framework to support reliable modelling and analysis.