<p>Nowadays, efforts are being made worldwide to find alternative chemical antibiotics to treat pathogenic bacteria in humans or animals. Therefore, this work modified silica obtained from rice husk with copper as an alternative to known antibiotics. A nanocomposite SiO₂@Cu(II) was prepared by treating a rice husk with copper ions. Then, by a reducing agent NaBH₄, the SiO₂@Cu(0) was synthesized. Several analytical techniques were used to prove the preparation of nanocomposites. For instance, in FTIR analysis, the stretching vibration of silanol and siloxane groups appeared around 3035&#xa0;cm⁻¹ and 1080&#xa0;cm⁻¹, respectively, while the bond between copper and oxygen Cu–O within the silica matrix appeared at 830&#xa0;cm⁻¹. The X-ray diffraction identified the amorphous and weak crystalline phases, indicating copper’s presence within the silica lattice. Based on N₂-(adsorption–desorption) analysis, SiO₂@Cu(II) and SiO₂@Cu(0) had specific surface areas of 80.143&#xa0;m²g⁻¹ and 100.980&#xa0;m²g⁻¹, respectively. Moreover, N₂ absorption–desorption proved that synthesized nanocomposite has an isothermal type IV and shows hysteresis loops H3. The electron microscopy analyses SEM, TEM, and AFM revealed that the morphology of the silica particles is mostly irregularly spherical, and copper particles were observed to be scattered within these shapes. The diffuse reflectance ultraviolet (DRUV-vis) absorption spectra of the nanocomposite appear as many electronic transitions that indicate charge transitions between oxygen and the metal, as well as transitions within the metal (d–d transitions) and gave an octahedral field around Cu(II). The antibacterial activity of nanocomposite was examined against two types of bacteria <i>S.aureus</i> and <i>E.coli</i>. The synthesized nanocomposites showed a promising result to control pathogenic bacteria that used in this study.</p>