Nanopattern-Assisted Direct Growth of Peony-like 3D MoS₂/Au Composite for Nonenzymatic Photoelectrochemical Sensing

Abstract

The chalcogenide material MoS 2 has been recognized as a promising candidate for photoelectrochemical (PEC) applications due to its enhanced photocatalytic and electrocatalytic activities. However, few reports have been focused on the designated catalytic MoS 2 for the nonenzymatic PEC sensing of small molecules. Here, we report on a novel in situ and fab-free method for the direct growth of three-dimensional (3D) porous Peony-like MoS 2 nanosheets supported by nanohole-patterned TiO 2 and composited with gold deposits. The direct growth resulted in enhanced electrical conductivity between the substrate and 3D-standing MoS 2 nanosheets and thus the uniform distribution of gold electrodeposits from the MoS 2 lattice. The hybrid 3D MoS 2 /gold nanocomposite demonstrated enhanced abundance of exposed catalytic edge sites and improved optic and electrical coupling, which ultimately led to excellent photoelectrochemical activities. We performed full characterization of the morphology, crystallinity, lattice configuration, and optical properties of hybrid MoS 2 nanosheets via field emission scanning microscope, high-resolution transmission electron microscopy, and energy-dispersive X-ray, Raman, and UV−vis spectroscopies. The 3D COMSOL simulation also confirmed enhanced electric field distribution at the interface of the proposed 3D MoS 2 /gold nanocomposite electrode in comparison with other morphologies. We acquired the Peony-like 3D MoS 2 /Au composite for photoelectrochemical sensing of glucose in buffer and diluted plasma solutions with a very low limit of detection of 1.3 nM and superb sensitivity in plasma. Overall, we have successfully synergized both electrical and optical merits from individual components to form a novel composite, which offered an effective scaffold for the development of PEC sensors.

Plasmonic Ag-Decorated Few-Layer MoS2 Nanosheets Vertically Grown on Graphene for Efficient Photoelectrochemical Water Splitting

“…6 c), indicating that a significant amount of light was extinguished by big Ag clusters (~ 60–100 nm) of G/MoS 2 /Ag-8 without photo-generation of e–h pairs in MoS 2 . The excessive surface coverage of metal NPs can also hinder contact of the electrochemical active surface with the electrolyte solution, resulting in deteriorated PEC activity [ 44 , 45 ]. In addition, the surface plasmons of small Ag NPs (< 30 nm) undergo decay because of the formation of energetic charge carriers, but those of large Ag NPs (> 50 nm) undergo decay through the radiative scattering of resonant photons [ 37 , 46 ].…”

Photoelectrochemical Water‐Splitting Using CuO‐Based Electrodes for Hydrogen Production: A Review

“…Recently, TMDs with their unique crystal structures, superior properties, and exotic functionalities have drawn intense attention in applications for piezoelectric devices, [ 319–321 ] batteries, [ 322–324 ] electronic devices, [ 325,326 ] photocatalysis, [ 327–331 ] biomedicine, [ 332–334 ] and PEC sensing. [ 335,336 ] In this regard, 2D TMDs can play an important role in energy production in the future. These materials, because of their remarkable energy bandgap, the facilitation of charge carrier transport, the ability to increase the active sites, tuning the phase, and electronic structure are suitable candidates for PEC applications.…”

Investigation of the Possibilities of Wool Fiber Surface Modification with Copper Selenide

“…New special composite materials, with varying combinations of physical and chemical properties, can be obtained by using textile fibers of various nature modified with thin semiconductive or electrically conductive coatings of binary inorganic compounds. Recently, composite materials with metal chalcogenide layers have attracted interest for their potential applications in established areas, such as solar radiation control [8], photovoltaic devices [9], sensitive elements for gas sensors [10], photo electronic devices [11], as promising candidates for photocatalytic and electro catalytic applications [12], etc.…”