In situ growth of naked Ag nanoparticles on graphene oxide was achieved following a simple, green, and environment-friendly one-step stirring method. In the absence of extra reductant and stabilizer, the naked Ag nanoparticles formed on the surface of GO via a spontaneous redox reaction between Ag⁺ and GO at room temperature. The morphology and microstructure of the resultant heterogeneous nanostructures were characterized by various spectroscopic and microscopic techniques systematically. The characterization results showed that the naked metallic Ag nanoparticles with an average diameter of 4.31 ± 0.13 nm distribute homogeneously and tend to “stand” in line on GO. The well-known catalytic hydrogenation of 4-nitrophenol by NaBH₄ was carried out to investigate the potential catalytic activity of the obtained heterogeneous Ag/GO nanocomposite. The obtained Ag/GO nanocomposite exhibited high catalytic ability with the apparent kinetics constant of 1.856 min⁻¹ and high turnover frequency of 2131.6 h⁻¹ and high structural and performance stability. It is believed that the small size and naked surface of the Ag nanoparticles, which provide abundant exposed catalytically active sites, facilitate greatly in improving the catalytic performance of Ag/GO. It is anticipated that the proposed green method is extendible to prepare other efficient noble-metal/GO nanocatalyst.

Graphical abstract

通过简单，绿色和环境友好的一步搅拌法，可在氧化石墨烯上实现裸银纳米颗粒的原位生长。在没有额外的还原剂和稳定剂的情况下，裸露的Ag纳米粒子在室温下通过Ag ⁺和GO之间的自发氧化还原反应在GO表面形成。所得的异质纳米结构的形貌和微观结构通过各种光谱学和显微技术进行了系统表征。表征结果表明，平均直径为4.31±0.13 nm的裸露金属Ag纳米颗粒均匀分布，并倾向于在GO上成一直线。NaBH ₄众所周知的4-硝基苯酚催化加氢进行了研究，以研究获得的非均相Ag / GO纳米复合材料的潜在催化活性。所获得的Ag / GO纳米复合材料表现出高的催化能力，其表观动力学常数为1.856 min ^-1，高周转频率为2131.6 h ^-1，并且具有较高的结构和性能稳定性。据信，提供大量暴露的催化活性位的Ag纳米颗粒的小尺寸和裸露的表面极大地促进了改善Ag / GO的催化性能。预期所提出的绿色方法可扩展以制备其他有效的贵金属/ GO纳米催化剂。

图形概要