The anti-oxidative potential of Rhamnidium elaeocarpum extract was assessed using a green chemical bottom-up approach to produce ~ 80 nm cubic Fe₃O₄ nanoparticles. The protocol makes use of FeCl₃ as the only precursor of magnetite, and it allows the obtaining of the material using water as solvent, and urea as a pH regulator. Besides, since the bark extract functions as both the capping and reducing agents, no unfriendly extra chemicals are required to promote the Fe³⁺ reduction to Fe²⁺. For comparison purposes, we also obtained iron oxide materials in the absence of the biomass, and it was observed that urea alone could not reduce Fe³⁺ to promote the formation of magnetite nanoparticles. In that case, other forms of iron oxide materials, with very low magnetic response, such as hematite (α-Fe₂O₃) and maghemite (γ-Fe₂O₃) were obtained. The bio-inspired catalyst (Fe₃O₄) was applied in the degradation of Rhodamine-B using H₂O₂. Under the studied conditions, a single portion of the catalyst could promote the dye degradation for at least 5 cycles (degradation > 94%), and the material could be rapidly isolated in between batches using a small neodymium magnet. We also found out that the iron oxides obtained in the absence of extract and urea exhibited a lower degradation efficiency, and could not be recycled in successive runs. An investigation on the toxicity of this new catalyst was also carried out on three model organisms and no toxicity enhancement could be induced by the presence of the as-synthesized magnetite nanoparticles.

使用绿色化学自下而上的方法生产约 80 nm 立方 Fe ₃ O ₄纳米粒子，评估了刺槐提取物的抗氧化潜力。该协议使用 FeCl ₃作为磁铁矿的唯一前体，它允许使用水作为溶剂和尿素作为 pH 调节剂来获得材料。此外，由于树皮提取物同时起到封端剂和还原剂的作用，因此不需要不友好的额外化学品来促进 Fe ³⁺还原为 Fe ²⁺。为了比较，我们还在没有生物质的情况下获得了氧化铁材料，观察到单独的尿素不能还原 Fe ³⁺促进磁铁矿纳米颗粒的形成。在这种情况下，获得了磁响应非常低的其他形式的氧化铁材料，例如赤铁矿（α-Fe ₂ O ₃）和磁赤铁矿（γ-Fe ₂ O ₃）。仿生催化剂（Fe ₃ O ₄）用于H ₂ O ₂降解罗丹明-B. 在所研究的条件下，单份催化剂可以促进染料降解至少 5 个循环（降解 > 94%），并且可以使用小型钕磁铁在批次之间快速分离材料。我们还发现，在没有提取物和尿素的情况下获得的氧化铁表现出较低的降解效率，并且无法在连续运行中回收利用。还在三种模式生物上对这种新催化剂的毒性进行了研究，并且合成的磁铁矿纳米粒子的存在不会引起毒性增强。