The present study reports an efficient, surfactant-free, novel and facile green method for the immobilization of Cu NPs on the surface of the graphene oxide/manganese dioxide (GO/MnO₂) nanocomposite using Cuscuta reflexa leaf extract. In fact the phytochemical content of the plant extract are responsible to biosynthesis of Cu nanoparticles (NPs) and their stabilization by functionalizing the surface of graphene. The Cu NPs were characterized by Fourier transformed infrared spectroscopy (FT-IR) and UV–visible spectroscopy. MnO₂ NPs and GO/MnO₂ nanocomposite were prepared by using a simple one-step hydrothermal method without using any toxic solvent. The synthesized GO/MnO₂ and Cu/GO/MnO₂ nanocomposites were characterized using X-ray diffraction analysis (XRD), field emission scanning electron microscope (FESEM), transmission electron microscopy (TEM) images, Brunauer–Emmett–Teller (BET), Thermogravimetric analysis (TGA), vibrating sample magnetometer (VSM), energy-dispersive X-ray spectroscopy (EDS), elemental mapping and FT-IR spectroscopy. The synthesized Cu/GO/MnO₂ nanocomposite was then successfully used as a reusable catalyst for the reduction of 2,4-dinitrophenilhydrazine (2,4-DNPH), 4-nitrophenol (4-NP), Rhodamine B (RhB), Congo red (CR), methyl orange (MO) and methylene blue (MB) using NaBH₄ in water at ambient temperature. This method is clean and environmentally friendly without using any toxic reducing agents.

本研究报告了一种有效的，无表面活性剂的新型绿色方法，该方法用于使用Cuscuta reflexa叶提取物将Cu NPs固定在氧化石墨烯/二氧化锰（GO / MnO ₂）纳米复合材料的表面上。实际上，植物提取物中的植物化学成分与铜纳米颗粒（NPs）的生物合成有关，并通过使石墨烯表面功能化来稳定它们。铜纳米颗粒的特征在于傅立叶变换红外光谱（FT-IR）和紫外可见光谱。MnO ₂ NPs和GO / MnO ₂纳米复合材料是通过简单的一步水热法制备的，无需使用任何有毒的溶剂。合成的GO / MnO ₂X射线衍射分析（XRD），场发射扫描电子显微镜（FESEM），透射电子显微镜（TEM）图像，Brunauer-Emmett-Teller（BET），热重分析（TGA）对Cu / GO / MnO ₂和Cu / GO / MnO ₂纳米复合材料进行了表征），振动样品磁力计（VSM），能量色散X射线光谱仪（EDS），元素映射和FT-IR光谱仪。合成的Cu / GO / MnO ₂纳米复合材料随后成功用作可重复使用的催化剂，用于还原2,4-二硝基苯并肼（2,4-DNPH），4-硝基苯酚（4-NP），若丹明B（RhB），刚果室温下在水中使用NaBH ₄的溶液，则呈红色（CR），甲基橙（MO）和亚甲基蓝（MB）。此方法清洁且对环境友好，无需使用任何有毒的还原剂。