Artificial enzymes have broad applications in catalysis and can be used to help understand catalytic mechanisms. Nanoceria has various enzyme-mimetic properties that depend on the relative content of Ce3+ and Ce4+ . In this context, CeO2 nanotubes was investigated as catalase mimics for water oxidation. The photosensitizer 5,10,15,20-meso-tetra(4-carboxyphenyl) porphyrin (TCPP) was facilely embedded in CeO2 nanotubes (TCPP@CeO2 NTs), and photoinduced charge transfer was shown to occur between the strongly coupled TCPP and CeO2 , which leads to effective charge separation and charge redistribution within the hybrids. As a consequence, formation of H2 O2 , a competing process in water oxidation and a key factor that affects the oxidative stability of photoelectrodes, was effectively inhibited on TCPP@CeO2 NTs. These findings show that enzyme mimics can be used for the selective generation of reactive oxygen species, and therefore to control the kinetics of water oxidation.

中文翻译：

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卟啉功能化的氧化铈纳米管的类似酶的催化活性，可用于水氧化。

人工酶在催化中具有广泛的应用，可用于帮助理解催化机理。纳米氧化铈具有多种酶模拟性质，这取决于Ce3 +和Ce4 +的相对含量。在这种情况下，研究了CeO2纳米管作为过氧化氢酶模拟物的水氧化作用。将光敏剂5,10,15,20-间-四（4-羧基苯基）卟啉（TCPP）轻松嵌入CeO2纳米管（TCPP @ CeO2 NTs）中，并显示在强耦合的TCPP和CeO2之间发生光诱导的电荷转移，从而在混合动力系统中实现有效的电荷分离和电荷重新分配。结果，在TCPP @ CeO2 NTs上有效抑制了H2 O2的形成，H2 O2是水氧化中的竞争过程，是影响光电极氧化稳定性的关键因素。