NiCo₂O₄ nanoneedle-assembled microflowers have been prepared by a facile one-pot hydrothermal route. The NiCo₂O₄ microflowers have a well-defined three-dimensional (3D) hierarchical mesoporous structure. When used as catalysts for the styrene oxidation, the 3D NiCo₂O₄ microflowers show a markedly high styrene conversion of 99% and a high selectivity of 80% to styrene oxide (SO). In addition, the NiCo₂O₄ catalysts exhibit good recycling stability. The excellent catalytic performance of the NiCo₂O₄ catalysts can be owing to the numerous surface active sites caused by the 3D hierarchical mesoporous structure and the possible synergistic effect between nickel and cobalt ions.

NiCo ₂ O ₄纳米针组装的微花已通过一种简便的一锅水热法制备。NiCo ₂ O ₄微型花具有定义明确的三维（3D）分层介孔结构。当用作苯乙烯氧化的催化剂时，3D NiCo ₂ O ₄微型花表现出99％的显着高苯乙烯转化率和80％的对苯乙烯氧化物（SO）的高选择性。另外，NiCo ₂ O ₄催化剂显示出良好的循环稳定性。NiCo ₂ O ₄的出色催化性能 催化剂可能是由于3D分层介孔结构以及镍和钴离子之间可能的协同作用所导致的大量表面活性位点所致。