Catalytic oxidation of formaldehyde (HCHO) at room temperature is a low-cost and efficient solution for indoor HCHO removal. In this work, NiCo2O4 nanowires were in-situ synthesized on nickel foam (NF) by a simple hydrothermal reaction and then decorated with platinum nanoparticles (NPs). The Pt/NiCo2O4-NF catalyst exhibited excellent HCHO oxidation capacity at ambient temperature, realizing a conversion rate of 90 % within 60 min. The nickel foam substrate prevents the aggregation of NiCo2O4 nanowire arrays. It also enables the growth of large-area and aligned nanowires, contributing to the uniform dispersion of Pt NPs. Moreover, due to the unique redox property and high reactivity of NiCo2O4, numerous surface oxygen vacancies and active oxygen species are generated together with Pt by NaBH4 reduction, which is beneficial to the adsorption and oxidation of HCHO. Moreover, the hierarchical macro-/mesoporous structure of Pt/NiCo2O4-NF facilitates the diffusion of gaseous reactants and provides easily accessible active sites. In contrast with nanosized catalysts, the three-dimensional (3D) Pt/NiCo2O4-NF catalyst possesses high machinability and practicability. This work may shed light on the fabrication of 3D hierarchical catalysts for oxidative HCHO removal and indoor air purification.

中文翻译：

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泡沫镍上的 Pt/NiCo2O4 纳米线阵列作为室温下高效甲醛氧化的催化剂


室温催化氧化甲醛 （HCHO） 是一种低成本且高效的室内 HCHO 去除解决方案。在这项工作中，通过简单的水热反应在泡沫镍 （NF） 上原位合成 NiCo2O4 纳米线，然后用铂纳米颗粒 （NPs） 装饰。Pt/NiCo2O4-NF 催化剂在环境温度下表现出优异的 HCHO 氧化能力，在 60 分钟内实现了 90 % 的转化率。泡沫镍衬底可防止 NiCo2O4 纳米线阵列的聚集。它还能够生长大面积和对齐的纳米线，有助于 Pt NP 的均匀分散。此外，由于 NiCo2O4 独特的氧化还原性能和高反应性，NaBH4 还原与 Pt 一起生成大量表面氧空位和活性氧，有利于 HCHO 的吸附和氧化。此外，Pt/NiCo2O4-NF 的分层宏/介孔结构促进了气态反应物的扩散，并提供了易于接近的活性位点。与纳米级催化剂相比，三维 （3D） Pt/NiCo2O4-NF 催化剂具有较高的可加工性和实用性。这项工作可能为用于氧化 HCHO 去除和室内空气净化的 3D 多级催化剂的制备提供启示。