Light welding Au nanoparticles assembled at water-air interface for monolayered nanoporous gold films with tunable electrocatalytic activity

• Published in: Electrochimica acta 2020-02, Vol.334, p.135626, Article 135626
• Main Authors: Han, Mei, Chen, Fei, Li, Moxia, Yu, Renpeng, Xu, Yaomengli, Jiang, Yuxiong, Liu, Cai, Hu, Jiawen
• Format: Article
• Language: English
• Subjects: Calomel electrode; Electrocatalytic activity; Gold; H2O2 sensor; Hydrogen peroxide; Light welding; Low temperature; Methanol; Methanol electrooxidation; Nanoparticles; Nanoporous gold film; Oxidation; Photonics; Self-assembly; Welding
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2020.135626

Nanoporous gold film (NPGF) has shown great potential for photonics, catalysis, sensing, and renewable energy. Herein, we report a monolayered NPGF with tunable electrocatalytic activity for improved methanol electrooxidation and H2O2 detection. The NPGFs were fabricated via interfacial self-assembly of Au nanoparticles (NPs) with different sizes and a subsequent light welding process. Amongst the NPGFs made from 16, 30, 55, and 70 nm Au NPs (denoted as x nm-NPGF, where x represents the size for the Au NPs), the 16 nm-NPGF shows the highest electrocatalytic activity, which is attributed to the synergistic contribution from its largest surface area, high conductivity, and the smallest hyperboloid-like ligaments that expose more high-index facets. Consequently, the optimized 16 nm-NPGF delivers a large current density of 151 μA cm−2 (at 0.22 V vs. saturated calomel electrode in 0.1 M KOH and 1.0 M methanol) for methanol electrooxidation. Moreover, it as well shows a good linear range (from 0.005 to 45 mM) for H2O2 detection, reaching a detection limit of 2.56 μM and sensitivity of 156.6 μA mM−1 cm−2. Our studies, thus, offer a low-temperature, solution-processable approach to fabricate monolayered NPGF from easily available Au NPs, without harsh dealloying process. [Display omitted] •Nanoporous Au film was fabricated by interfacial assembly of Au nanoparticles and a light welding process.•Its nanostructure and in turn electrocatalytic properties can be tuned by changing the size of the starting Au nanoparticles.•The optimized NPGF shows excellent catalytic activity for methanol electrooxidation and H2O2 detection.