Recently, active bubble-propelled micromotors have attracted great attention for fuel applications. However, for generating bubble-propelled micromotors, additional catalysts, such as Pt, Ag, and Ru, are required. These catalysts are expensive, toxic, and highly unstable for broad applications. To overcome these issues, in this study, we present an innovative methodology for the preparation of self-propelled motor machines using naturally occurring diatom frustules. This natural diatom motor shows effective motion in the presence of a very low concentration (0.8%) of H₂O₂ as a fuel at pH 7. Due to the unique 3D anisotropic shape of the diatom, the self-propelled motor exhibited unidirectional motion with a speed of 50 μm s⁻¹ and followed pseudo first-order kinetics. It was found that a trace amount of iron oxide (Fe₂O₃) in the diatom was converted into Fe₃O₄, which can act as a catalyst to achieve the facile decomposition of H₂O₂. Interestingly, “braking” of the unidirectional motion was observed upon treatment with EDTA, which blocked the catalytically active site. These results illustrate that diatom catalytic micromotors have opened a new era in the field of catalysis and bioengineering applications.

中文翻译：

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在低燃料浓度下 通过H ₂ O ₂催化分解以生物启发的自行式硅藻微电机†

近来，有源气泡推进微电机在燃料应用中引起了极大的关注。然而，为了产生气泡推进的微型电动机，需要额外的催化剂，例如Pt，Ag和Ru。这些催化剂昂贵，有毒并且对于广泛的应用是高度不稳定的。为了克服这些问题，在这项研究中，我们提出了一种使用自然存在的硅藻壳制备自走式电机的创新方法。这种自然硅藻马达在pH值为7的H ₂ O ₂浓度极低（0.8％）作为燃料的情况下显示出有效的运动。由于硅藻的独特3D各向异性形状，自推进式马达表现出单向运动速度为50μms ^-1并遵循伪一阶动力学。结果发现，硅藻中的痕量氧化铁（Fe ₂ O ₃）被转化为Fe ₃ O ₄，可以作为催化剂实现H ₂ O ₂的容易分解。有趣的是，在用EDTA处理后观察到单向运动的“制动”，这阻止了催化活性位点。这些结果说明硅藻催化微电机在催化和生物工程应用领域开辟了一个新时代。