## 1 Introduction  
Nanohybrid structures are very interesting materials and have attracted a considerable amount of attention from many researchers because of their remarkable physical and chemical properties that cannot be accomplished by the usual solid-state reactions [1; 2; 3; 4; 5; 6; 7; 8; 9]. This trend is very creative because the diverse properties of the different species can be collected in one material. The incorporation of two or more inorganic species, having one dimension or two dimensions in the nanoscale, is an efficient way to design hybrid material. The challenge is to produce a homogeneous and stable system of nanohybrids. In order to minimize the degree of phase separation for the hybrid materials, layered double hydroxides can be useful in this trend because they have the ability to collect two or more inorganic metals in an order arrangement inside their layers with thicknesses of 0.48 nm [1; 2; 3; 4]. In addition, organic or inorganic species can be intercalated inside their interlayered region through host-guestintercalation processes [5]. These intercalation processes occur through creating a positive charge on the nanolayers of layered double hydroxides (LDHs) because of the presence of divalent and trivalent metals together inside these nanolayers, which act as a host. Organic or inorganic anions intercalate to neutralize the positive charges of the nanolayers and act as guests. LDHs are defined by the general formula [M1\(\times\)M*x(OH)\({}_{2}\)]\({}^{2+}\)(A\({}^{\text{n}-}\))\({}_{2/\text{n}}\)\(\gamma\)H\({}_{2}\)O. M and M* are divalent cations (e.g., Zn\({}^{2+}\), Fe\({}^{2+}\), Mg\({}^{2+}\), Ni\({}^{2+}\), Cu\({}^{2+}\), or Co\({}^{2+}\)) and trivalent cations (e.g., Cr\({}^{3+}\), Al\({}^{3+}\), Ga\({}^{3+}\), In\({}^{3+}\), or Fe\({}^{3+}\)), respectively; A\({}^{\text{n}-}\) represents organic or inorganic anions [10; 11; 12; 13; 14]. Recently, a narrow number of monovalent and tetravalent cations such as lithium, titanium, tin, and zirconium was inserted in the host layers of LDH structures. However, there is no data available in the literature for silicon (Si\({}^{4+}\)). Cobalt and silicon are widely known to have major roles in coloring glasses [15], the photothermal conversion of solar energy [16], and in several technically orientated glass applications [17]. A combination of cobalt and silicon is employed in different applications [18; 19; 20; 21; 22; 23; 24; 25] such as refractories materials, advanced ceramic industry, magnetic materials, ceramic pigment, electrical conductivity, batteries, catalysts, and gas sensors because of their remarkable magnetic, electrical, and optical properties in addition to their high oxidation activity and stabilization at high temperature. In this trend, the photofunctional guest molecules can be assembled with the LDHs host layers containing photoactive metals to build a new type of host-guest nanohybrid materials with advanced photo-related performances such as a low band gap. Some positive effects can be obtained from the confinement of dual anions inside the nanolayered structures of multi-metal LDHs. The vibration and thermal motion of guests can be controlled in the confined interlayer space to improve the efficiency of the photoactive molecules and change their morphologies. In addition, the regular layers of multi-metal LDHs allow an ordered arrangement of different metals to minimize the degree of phase separation and obtain homogeneous nanohybrids. In this study, our research focuses on a combination of cobalt and silicon through layered double hydroxides with different morphologies, although there is no data available for this material in the literature. In the same time, a dual anion intercalation process is used to control the morphology of LDHs. Nanofibers of Co-Si LDHs are prepared and characterized by different techniques. In addition, the crystalline structure and the morphology of Co-Si LDHs are developed by inserting other inorganic tetravalent metals such as titanium and zirconium.