Microwave-Sample-Preparation-System-Assisted Biogenic Synthesis of Copper Oxide Nanoplates Using Saussurea costus Root Aqueous Extract and Its Environmental Catalytic Activity

Using safe and environmentally benign materials is considered one of the green chemistry approaches to avoid waste production. This research reported the biogenic synthesis of CuO nanoplates using Saussurea costus root extract assisted by a microwave sample preparation system. The phytochemical contents in the Saussurea costus root aqueous extract work as the reducing and capping agents for the nanoparticles. The biosynthesized CuO nanoplates were analyzed using UV–Vis spectroscopy, FT-IR, XRD, HR-TEM, DLS, FESEM, and EDS techniques. According to the HR-TEM and FE-SEM results, the CuO nanoparticles exhibited a plate-like shape with a mean size of 29 nm. Furthermore, the XRD results showed a typical agreement with the pattern of the monoclinic phase of copper oxide. The catalytic efficiency of the CuO nanoplates in the reduction of 4-nitrophenol to 4-aminophenol using NaBH4 was examined in terms of environmental catalytic activity. The reaction time took less than 10 min. Thus, CuO nanoplates synthesized via Saussurea costus root aqueous extract show high catalytic-activity potential for the environmental catalytic application of the removal of nitro pollutants.