Department of Environmental Science, Zhejiang University, Hangzhou 310058, China; Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control, Hangzhou 310058, China.
Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA.
Sci Total Environ. 2021 Jun 1;771:145396. doi: 10.1016/j.scitotenv.2021.145396. Epub 2021 Jan 27.
The precisely coupling of metal nanoparticles with support domain are crucial to enhance the catalytic activity and stability of supported metal nanoparticle catalysts (MNPs). Here we selectively anchor Pd nanoparticles to the sp domain in graphene-based aerogel constructed with base-washed graphene oxide (BGO) by removing oxidative debris (OD). The effects of OD on the size and chemical composition of Pd nanoparticles in aerogels are initially unveiled. The removal of OD nanoparticles prompt selective coupling of Pd nanoparticles to the exposed sp-hybridized domain on BGO nanosheets, and then prevent it from agglomeration. As a result, the Pd nanoparticle size of self-assembled Pd/BGA is 4.67 times smaller than that of traditional Pd/graphene oxide aerogel (Pd/GA). The optimal catalytic activity of Pd/BGA for the model catalytic reduction of 4-nitrophenol is 15 times higher than that of Pd/GA. Pd/BGA could maintain its superior catalytic activity and achieves 98.72% conversion in the fifth cycle. The superior catalytic performance could be ascribed to the small Pd nanoparticles and high percentage of Pd(0) in Pd/BGA, and the enhanced electronic conductivity of Pd/BGA. These integrated merits of Pd/BGA as heterogeneous catalysts are attributed to selectively anchor Pd nanoparticles on sp-hybridized domain of graphene-based aerogel, and strongly coupled interaction of MNPs with support. The structure-regulated BGO nanosheets could serve as versatile building blocks for fabricating MNPs/graphene aerogels with superior performance for catalytic transformation of water pollutants.
精确地将金属纳米粒子与载体域偶联对于提高负载型金属纳米粒子催化剂 (MNPs) 的催化活性和稳定性至关重要。在这里，我们通过去除氧化碎片 (OD)，选择性地将钯纳米粒子锚定在由基底处理的氧化石墨烯 (BGO) 构建的基于石墨烯的气凝胶的 sp 域中。首先揭示了 OD 对气凝胶中 Pd 纳米粒子尺寸和化学成分的影响。去除 OD 纳米粒子会促使 Pd 纳米粒子选择性地偶联到 BGO 纳米片上暴露的 sp 杂化域上，从而防止其聚集。结果，自组装的 Pd/BGA 中的 Pd 纳米粒子尺寸比传统的 Pd/氧化石墨烯气凝胶 (Pd/GA) 小 4.67 倍。Pd/BGA 对 4-硝基苯酚模型催化还原的最佳催化活性比 Pd/GA 高 15 倍。Pd/BGA 可以在第五个循环中保持其优越的催化活性，达到 98.72%的转化率。Pd/BGA 的优越催化性能可归因于 Pd/BGA 中较小的 Pd 纳米粒子和较高比例的 Pd(0)，以及 Pd/BGA 增强的电子导电性。作为多相催化剂，Pd/BGA 的这些综合优点归因于将 Pd 纳米粒子选择性地锚定在基于石墨烯的气凝胶的 sp 杂化域上，以及 MNPs 与载体之间的强耦合相互作用。结构调节的 BGO 纳米片可用作制造 MNPs/石墨烯气凝胶的多功能构建块，这些气凝胶在水污染物的催化转化方面具有优异的性能。
