Black phosphorus (BP), as a promising star of two-dimensional (2D) van der Waals family, has attracted extensive attention for its characteristic dimension effects, mechanical properties and thermal stability. Herein, we report a facile strategy of integrating aryl diazonium modified few Layer black phosphorus with loading of ultrafine yttrium oxide (BP-NH-Y), for reducing the fire hazard of epoxy resin (EP). The results of cone calorimetry test results manifest that the flame retardancy of EP can significantly improve by adding 2 wt% BP-NH-Y, for instance, the peak heat release rate (pHRR) and the total heat release (THR) is reduced by 47.0% and 48.1%, respectively. Especially, adding the BP-NH-Y nanosheets distinctly inhibite the diffusion of EP pyrolysis products (such as toxic CO, hydrocarbons etc.) during flaming. In particular, epoxy composites with only 1.0 wt% BP-NH-Y were able to achieve UL-94 V-0 rating with an oxygen index of more than 30. This work may have a promising prospect for developing efficient covalent functionalized BP nanosheets to meet the needs of sustainable applications.

黑磷（BP）作为二维（2D）范德华家族的一颗有前途的恒星，以其特有的尺寸效应、力学性能和热稳定性引起了广泛的关注。在此，我们报告了一种将芳基重氮改性的少层黑磷与负载超细氧化钇 (BP-NH-Y) 相结合的简便策略，以降低环氧树脂 (EP) 的火灾危险。锥形量热试验结果表明，加入 2 wt% BP-NH-Y 可显着提高 EP 的阻燃性，例如峰值放热率 (pHRR) 和总放热率 (THR) 降低分别为 47.0% 和 48.1%。特别是，添加 BP-NH-Y 纳米片明显抑制了 EP 热解产物（如有毒 CO、碳氢化合物等）在燃烧过程中的扩散。特别是，