Preparation of urchin like structures of SiO2/CuO by low temperature hydrothermal synthesis as adsorbent for dyes and efficient catalyst for 4-nitrophenol

Due to the relevance of SiO2/CuO nanocomposites as catalysts, adsorbents, and magnetic materials, continuing research is being done to find more affordable ways of synthesizing them. In the present study, a short-term hydrothermal approach (90 °C for 4 hrs) has been adapted to prepare a uniform urchin-like SiO2 /CuO composite (USC). The prepared composite has been demonstrated to have adsorption as well as catalytic properties. This material therefore has a great potential for use in environmental remediation. The prepared material was characterized by using XRD, SEM, TEM, FTIR, and UV spectroscopy techniques. Surface area analysis revealed that it possesses a specific surface area of 675.5 m2/g which leads to enhanced adsorption by providing access to more active sites for the adsorption. Various anionic and cationic dyes were evaluated for the adsorption process by prepared adsorbent. We discovered that the adsorbent was incredibly effective in capturing the cationic dye (RhB) with an adsorption capacity of 69.4 mg/g; therefore, adsorption parameters such as time, concentration of dye, pH, etc. were studied for the adsorption of RhB. Whereas, 4-NP was 63% eliminated by the SiO2 /CuO by using NaBH4 as reducing agent. Further studies revealed that SiO2 /CuO was able to reproduce and reused to 5 adsorption cycles and follow monolayer adsorption. Using USC adsorbent for more versatile applications in environmental cleanup could be made possible by this work.