Synthesis of Ultrastable Ag Nanoplates/Polyethylenimine–Reduced Graphene Oxide and Its Application as a Versatile Electrochemical Sensor

Abstract

Investigations on Ag nanostructures/reduced graphene oxide composites have been frequently reported, yet the morphology control of those loaded Ag nanocrystals is still challenging. We herein develop a facile method to grow triangular Ag nanoplates (AgP) on polyethylenimine-modified reduced graphene oxide (AgP/PEI-rGO). The AgP/PEI-rGO hybrids show unexpected high stability against chloride ions (Cl(-) ) and hydrogen peroxide (H2 O2 ), which is possibly due to the strong interaction between surface Ag atoms with the amine groups of PEI. In the chronoamperometry measurements for detecting H2 O2 , N2 H4 , and NaNO2 , the AgP/PEI-rGO hybrid shows very wide linear ranges (usually 10(-6) -10(-2) mol L(-1) for H2 O2 , N2 H4 , and NaNO2 ) and low detection limits (down to ≈1×10(-7) mol L(-1) ), which demonstrate the promising electrochemical sensor applications of these metal/graphene hybrids with well-defined morphologies and facets. In addition, this strategy could be extended to the deposition of other noble metals on rGO with controlled morphologies.

Advancement of Ag–Graphene Based Nanocomposites: An Overview of Synthesis and Its Applications

“…Wang et al found that Ag nanoplates (AgP) on polyethylenimine‐modified rGO (AgP/PEI‐rGO) could be used as promising electrochemical sensor for detecting chloride ions (Cl − ), N 2 H 4 , and NaNO 2 . Importantly, the modified electrodes still showed good detection performance even in the interference of some inorganic ions and organic materials . Ag–graphene based composites also can be used as gas sensors .…”

Sheetlike gold nanostructures/graphene oxide composites via a one-pot green fabrication protocol and their interesting two-stage catalytic behaviors

“…So far, numerous nanoplates of Ag, Pt, and Au have been successfully formulated via the twodimensional template effect of GO. [36][37][38][39][40][41][42][43] Nevertheless, in these cases, the fabrication has to be fullled with the assistance of appropriate alkylamine, 36,37 polyethylenimine, 38 tannic acid, 39 a molten salt medium, 40 a heating or hydrothermal treatment, 41,42 or an electrochemical process. 43 It thus is strongly desired to launch a facile yet green protocol to produce Au nanoplates/GO composites under ambient conditions without the use of non-environmentally friendly chemicals or specic apparatus.…”

One-Step Synthesis of Tunable-Size Gold Nanoplates on Graphene Multilayers

“…For the synthesis of Au nanoplates, chloroauric acid (HAuCl 4 ) is the most commonly used Au precursor, and solutions containing iodide or bromide ions are added to facilitate anisotropic morphologies; ,− these approaches typically involve multiple processing steps, the use of seed crystals, and irradiation using energetic electron beams . Graphene and graphene oxide supported Au and Ag nanoplates − have been prepared via the annealing of gold thin films and nanoparticles . Studies have shown that spontaneous redox reactions involving galvanic displacement between Au 3+ in the precursor and sp 2 -bonded C in carbon structures ,− and Au-graphene interfacial interactions, while weak, are both expected to influence the morphologies of Au crystals on graphene. , The graphene layers not only provide nucleation sites and support for the Au nanoplates but also act as reduction agent.…”