| Abstract | Urea (CO(NH2)2) is a low-cost, water-soluble fertilizer that is used as the main source of nitrogen in agricultural production. However, urea leaching is now a major problem, which results in inefficient nutrient absorption, low crop yield, economic failure for farmers, as well as groundwater pollution due to release of excessive amounts of nitrate through irrigation. Therefore, recent research focuses on integrating urea into a stable matrix that releases the desired fertilizer with an optimal time window. Tabasheer-derived porous silicon (pSi) was chosen as the material of interest due to its porous surface morphology, biodegradability and biocompatibility. The material is believed to interact with urea via hydrogen bonds (via surface silanol species), and thus its porous structure is the key to trap urea particles for relatively long periods in water, while exposing the fertilizer to plants. In this study, urea was wet-loaded into pSi. The porosity and loading capacity of pSi/urea composite were characterized by Field Emission Scanning Electron Microscopy (FESEM), X-ray Diffraction (XRD), Thermogravimetric Analysis (TGA), and Differential Scanning Calorimetry (DSC), before release kinetics experiments were conducted. The results of the release kinetics of pSi suggest that more improvement needs to be made to enhance the material. |
