Fe/N-doped carbon magnetic nanocubes (Fe/N–C MNCs) were feasibly fabricated through in situ thermal transformations of Prussian blue nanocubes (PB NCs) in an inert atmosphere, and the resultant composite employed as the heterogeneous noble-metal-free catalyst possessed satisfactory catalytic performance in hydrogen peroxide activation. By examining the properties of Fe/N–C MNCs, we demonstrate for the first time that the catalyst could act in synergy with ultrasonic irradiation and accelerate the selectivity of the degradation reaction of dyes. The degradation efficiency of the organic positively charged dye (methylene blue) is significantly increased after ultrasonic irradiation addition, probably owing to charge matching between a positively charged dye and the Fe/N–C MNCs. Interestingly, organic pollution degradation mainly follows a non-radical pathway. Furthermore, singlet oxygen (¹O₂) is predominantly produced by Fe/N–C MNCs on H₂O₂ activation, and it is the contributor to catalytic degradation instead of hydroxyl and/or superoxide anion radicals. Moreover, the Fe/N–C MNCs exhibit excellent stability and reusability. These findings offer interesting insights into the potential application of functional noble-metal-free materials in catalysis and wastewater remediation under ultrasonic radiation.

Fe/N 掺杂的碳磁性纳米立方体（Fe/N-C MNCs）是通过普鲁士蓝纳米立方体（PB NCs）在惰性气氛中的原位热转变制备的，所得复合材料用作异质无贵金属催化剂在过氧化氢活化中具有令人满意的催化性能。通过检查 Fe/N-C MNCs 的性质，我们首次证明催化剂可以与超声波辐射协同作用并加速染料降解反应的选择性。添加超声波辐照后有机带正电染料（亚甲蓝）的降解效率显着提高，这可能是由于带正电染料与 Fe/N-C MNC 之间的电荷匹配。有趣的是，有机污染降解主要遵循非自由基途径。此外，单线态氧（¹ O ₂ ) 主要由 Fe/N-C MNC 在 H ₂ O ₂活化时产生，它是催化降解的贡献者，而不是羟基和/或超氧阴离子自由基。此外，Fe/N-C MNCs 表现出优异的稳定性和可重用性。这些发现为功能性无贵金属材料在超声辐射下的催化和废水修复中的潜在应用提供了有趣的见解。