Johannes Gutenberg-Universität Mainz, Department Chemie, Duesbergweg 10-14, D-55128 Mainz, Germany.
Nanoscale. 2023 Mar 16;15(11):5209-5218. doi: 10.1039/d2nr02575b.
Designing the size, morphology and interfacial charge of catalyst particles at the nanometer scale can enhance their performance. We demonstrate this with nanoceria which is a functional mimic of haloperoxidases, a group of enzymes that halogenates organic substrates in the presence of hydrogen peroxide. These reactions in aqueous solution require the presence of HO. We demonstrate generation of HO from a CaO reservoir in polyether sulfone (PES) and poly(vinylidene fluoride) (PVDF) polymer beads, which circumvents the external addition of HO and expands the scope of applications for haloperoxidase reactions. The catalytic activity of nanoceria was enhanced significantly by Bi substitution. Bi-doped mesoporous ceria nanoparticles with tunable surface properties were prepared by changing the reaction time. Increasing reaction time increases the surface area of the mesoporous BiCeO nanoparticles and the Ce/Ce ratio, which is associated with the -potential. In this way, the catalytic activity of nanoceria could be tuned in a straightforward manner. HO required for the reaction was released steadily over a long period of time from a CaO storage depot incorporated in polyether sulfone (PES) and poly(vinylidene fluoride) (PVDF) beads together with BiCeO particles, which may be used as precision fillers and templates for biological applications. The spheres are prepared as a dry powder with no surface functionalization or coatings. They are inert, chemically stable, and safe for handling. The feasibility of this approach was demonstrated using a haloperoxidase assay.
在纳米尺度上设计催化剂颗粒的大小、形态和界面电荷可以提高其性能。我们用纳米氧化铈来证明这一点，纳米氧化铈是过氧化物酶的功能模拟物，过氧化物酶是一组在过氧化氢存在下卤化有机底物的酶。这些在水溶液中的反应需要 HO 的存在。我们证明了在聚醚砜（PES）和聚偏二氟乙烯（PVDF）聚合物珠粒中的 CaO 储库中产生 HO，这避免了外部添加 HO，并扩展了过氧化物酶反应的应用范围。通过 Bi 取代，纳米氧化铈的催化活性得到了显著提高。通过改变反应时间，制备了具有可调表面性质的 Bi 掺杂介孔氧化铈纳米粒子。增加反应时间会增加介孔 BiCeO 纳米粒子的表面积和 Ce/Ce 比，这与 -电位有关。通过这种方式，可以以简单直接的方式调整纳米氧化铈的催化活性。HO 是反应所必需的，它与 BiCeO 颗粒一起从掺入聚醚砜（PES）和聚（偏二氟乙烯）（PVDF）珠粒中的 CaO 储存库中稳定地释放出来，这可能被用作生物应用的精密填充剂和模板。这些球体是作为干粉末制备的，没有表面官能化或涂层。它们是惰性的、化学稳定的，并且处理安全。过氧化物酶测定法证明了这种方法的可行性。
