Multifunctional Reduced Graphene Oxide Wrapped Circular Au Nanoplatelets: Enhanced Photoluminescence, Excellent Surface-Enhanced Raman Scattering, Photocatalytic Water Splitting, and Non-Enzymatic Biosensor

Abstract

Herein, we demonstrate the synthesis and multifunctional properties of reduced graphene oxide (RGO)-wrapped Au nanoplatelets. We have characterized the sample by field emission scanning electron microscope (FESEM), high-resolution transmission electron microscope (HRTEM), energy-dispersive X-ray spectroscopy (EDS), high-angle annular dark-field scanning transmission electron microscopy (STEM-HAADF), electron energy-loss spectroscopy (EELS), and X-ray photoelectron spectroscopy (XPS) studies. It has been shown that the RGO wraps a large number of 2D circular Au nanoplatelets (diameter ∼15 nm). We have examined the optical property of the sample using Raman, UV–vis, and PL spectroscopic techniques. Large enhancement in intensity of Raman spectra was observed due to the surface enhanced Raman scattering (SERS) resulting from the Au nanoplatelets. The collective sway of surface plasmon resonance and fluorescence resonance energy transfer effect owing to Au gives rise to giant enhancement in intensity of photoluminescence emission spectrum. Upon visible-light irradiation, photocurrent flows through the sample due to interband 6sp transition within the Au nanoplatelets and it exhibits photocatalytic water splitting effect. The sample displays excellent nonenzymatic hydrogen peroxides (H2O2) and ascorbic acid (AA) sensing property. The value of sensitivity for H2O2 is 280.28 μA mM–1 cm–2 in the linear range of 1 μM to 0.8 mM and that for AA is 314.07 μA mM–1 cm–2 in the linear range of 25–300 μM. The lowest detection limit of both H2O2 and AA is 6.8 μM at S/N= 3. So, the sample can be used for multifunctional applications in SERS as substrate, photocatalytic water splitting, photodetectors, and nonenzymatic biosensing.

Flower-Like MoS2 for Next-Generation High-Performance Energy Storage Device Applications

“…Nano-/micro-sized materials have created major interest due to their wide variety of potential applications (Majumder et al, 2015a(Majumder et al, , 2015b(Majumder et al, , 2016(Majumder et al, , 2018a(Majumder et al, , 2018bPal et al, 2018). Energy-related issues have attracted a good deal of attention in recent years.…”

2D Material‐Based Optical Biosensor: Status and Prospect

“…Majumder et al found that the circular gold nanosheets coated with multifunctional reduced graphene oxide greatly enhanced the photoluminescence emission intensity caused by the common wobble of SPR and the fluorescence resonance energy transfer effect through the enhancement of Raman spectrum intensity. [205] Thus, under visible light irradiation, photocurrent flows through the sample to show the photocatalytic decomposition of water, indicating that it has great potential in the detection of nonenzymatic H 2 O 2 and ascorbic acid.…”

Graphene and graphene‐like structure from biomass for Electrochemical Energy Storage application‐ A Review

“…On a wider note, there are three ways to improve the interfacial contact between the electrolyte and the electrode: (1) configuring a porous structure into the graphene derived composites by etching holes into the structure; (2) improving the electrolyte wettability of the same by altering its configuration by introducing functional groups or defects, heteroatom doping onto the planes of graphene, etc; and (3) Altering the graphene component's course in the composites. [ 43 ] Various graphene covered composites like graphene covered particles, [ 72 ] hollow spheres, [ 73 ] nanoplatelets, [ 74 ] and nanowires have been engineered for EES. Substantial specific surface area, higher magnitude of the packing density of active materials, optimized electrode thickness, high pore connectivity, and ionic conductivity are the major features that would result in supercapacitors with high energy density.…”

“…Substantial specific surface area, higher magnitude of the packing density of active materials, optimized electrode thickness, high pore connectivity, and ionic conductivity are the major features that would result in supercapacitors with high energy density. [ 74 ] However, some of the criteria are contradictory to one another, thereby making the optimization process a challenging one. For example, an increase in packing density would influence in reducing the ion accessibility and pore interconnectivity which in turn affects the value of specific capacitance and rate capability.…”