NiFe₂O₄ nanoparticles are modified by graphene quantum dots (GQDs) and utilized to stabilize the Cu(II) nanoparticles as a novel magnetically retrievable catalytic system (Cu(II)/GQDs/NiFe₂O₄) for green formation of 4H‐pyrimido[2,1‐b]benzothiazoles. The prepared catalyst can be isolated assisted by an outer magnet and recovered for five courses without significant reduction in its efficiency. The as‐prepared magnetic heterogeneous nanocomposite was characterized by UV–Vis, FT‐IR, XRD, EDS, VSM, TEM, and ICP. Performing the reactions in environmentally friendly and affordable conditions (water), the low catalyst percentage, high yield of products, short reaction times, and easy workup are the merits of this protocol.

中文翻译：

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铜（II）负载的石墨烯量子点修饰的NiFe2O4：一种绿色高效的水中合成4H-嘧啶[2,1-b]苯并噻唑的催化剂

NiFe ₂ O ₄纳米粒子通过石墨烯量子点（GQD）进行了修饰，并用于稳定Cu（II）纳米粒子，作为一种新型的可磁化催化体系（Cu（II）/ GQDs / NiFe ₂ O ₄），用于绿色形成4H嘧啶并[2,1-b]苯并噻唑。所制得的催化剂可以在外磁体的辅助下进行分离，并回收五个过程，而效率没有明显降低。所制备的磁性异质纳米复合材料的特征在于：UV-Vis，FT-IR，XRD，EDS，VSM，TEM和ICP。在环保和负担得起的条件下（水）进行反应，低催化剂百分率，高收率的产品，较短的反应时间和容易的后处理是该方案的优点。