Intrinsic electrochemical performance and precise control of surface porosity of graphene-modified electrodes using the drop-casting technique

Eng, Alex Yong Sheng; Chua, Chun Kiang; Pumera, Martin

doi:10.1016/j.elecom.2015.07.001

Cited by 29 publications

(18 citation statements)

References 31 publications

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“…On the other hand, electrochemical synthesis is a simple green bottom-up synthesis process that utilizes aqueous electrolytes at room temperature with minimal set up required . The electrochemical synthesis presents multiple advantages over the above-mentioned techniques, which includes versatility in the choice of substrate and electrochemical technique, rapid, ease of operation, scalability, and control over thickness of deposited material. , It also renders the catalyst immobilization step redundant, dispelling doubts of porosity and roughness resulting in the observed catalytic activity. , In light of sustainable energy generation, electrodeposition is currently an established sample preparation method in the field of solar cells, − and toward lab-on-chip applications, it has also been experimented for microelectronic manufacturing. − For the electrochemical synthesis of transition metal chalcogenides, chronoamperometry, chronopotentiometry, and cyclic voltammetry (CV) are generally techniques of choice. In particular, the electrodeposition of TMDs was first explored by Belanger et al to form amorphous MoS 3 films .…”

Section: Introductionmentioning

confidence: 99%

Bottom-up Electrosynthesis of Highly Active Tungsten Sulfide (WS_3–x) Films for Hydrogen Evolution

Tan

Pumera

2016

ACS Appl. Mater. Interfaces

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Transition metal dichalcogenides have been extensively studied as promising earth-abundant electrocatalysts for hydrogen evolution reaction (HER). However, despite the intention to achieve sustainable energy generation, conventional syntheses typically use environmentally damaging reagents and energy-demanding preparation conditions. Hence, we present electrochemical synthesis as a green and versatile alternative to traditional methods. In this fundamental study, we demonstrated the bottom-up synthesis of a mixed WS2/WS3 film-like material via cyclic voltammetry (CV). The film-like material can be directly electrosynthesized on any conductive substrates and renders the catalyst immobilization step redundant. Through stepwise analysis of deposition voltammograms facilitated by straightforward modification of CV conditions, and characterization using X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS), a two-step mechanism involving the initial WS3 deposition and subsequent partial reduction to WS2 was proposed. The WS2/WS3 material was determined to possess composition of WS2.64. Compared to non-electrosynthesized WSx materials, its predominantly basal orientation limited the heterogeneous electron transfer rate toward surface-sensitive redox couples. However, WS2.64 demonstrated excellent HER activity, with the lowest Tafel slope of 43.7 mV dec(-1) to date; this was attributed to different metal-chalcogen binding strengths within WS2.64. Fundamental understanding of the electrosynthesis process is crucial for green syntheses of inexpensive and highly electrocatalytically active materials for sustainable energy production. Albeit, the process may be different for a myriad of nanomaterials, this study can be exploited for its analyses from which the conclusions were made, to empower electrochemical synthesis as the prime fabrication approach for HER electrocatalyst development.

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Section: Introductionmentioning

confidence: 99%

Bottom-up Electrosynthesis of Highly Active Tungsten Sulfide (WS_3–x) Films for Hydrogen Evolution

Tan

Pumera

2016

ACS Appl. Mater. Interfaces

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“…From the XRD diffractogram (Figure S5), the interlayer spacing of GO sheets was calculated to be 0.91 nm using Bragg's Law. This interlayer distance behaves as ideal nanochannels and/or nanocavities for electrolyte diffusion and accumulation [17b]. The oxygenated functional groups prevent the aggregation of multilayer film sheets, allowing a higher permeation of ions and interaction within the structural void spaces [20].…”

Section: Resultsmentioning

confidence: 99%

Interfacial Capacitance of Graphene Oxide Films Electrodes: Fundamental Studies on Electrolytes Interface Aiming (Bio)Sensing Applications

et al. 2021

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The understanding of bidimensional materials dynamics and its electrolyte interface equilibrium, such as graphene oxide (GO), is critical for the development of a capacitive biosensing platform. The interfacial capacitance (C i ) of graphene-based materials may be tuned by experimental conditions such as pH optimization and cation size playing key roles at the enhancement of their capacitive properties allowing their application as novel capacitive biosensors. Here we reported a systematic study of C i of multilayer GO films in different aqueous electrolytes employing electrochemical impedance spectroscopy for the application in a capacitive detection system. We demonstrated that the presence of ionizable oxygen-containing functional groups within multilayer GO film favors the interactions and the accumulation of cations in the structure of the electrodes enhancing the GO C i in aqueous solutions, where at pH 7.0 (the best condition) the C i was 340 μF mg À 1 at À 0.01 V vs Ag/AgCl. We also established that the hydrated cation radius affects the mobility and interaction with GO functional groups and it plays a critical role in the Ci, as demonstrated in the presence of different cations Na + = 640 μF mg À 1 , Li + = 575 μF mg À 1 and TMA + = 477 μF mg À 1 . As a proof-ofconcept, the capacitive behaviour of GO was explored as biosensing platform for standard streptavidin-biotin systems. For this system, the C i varied linearly with the log of the concentration of the targeting analyte in the range from 10 pg mL À 1 to 100 ng mL À 1 , showing the promising applicability of capacitive GO based sensors for label-free biosensing.

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“…We stress that the amount of the modification material influences the electrochemical performances of the electrode (see [ 63 , 64 ]). Therefore, here, the concentration of the nanomaterials used to modify the electrode was optimized by looking for the saturation amount able to ensure the reproducibility of the electrochemical performance of devices.…”

Section: Methodsmentioning

confidence: 99%

Sensitive Detection of Industrial Pollutants Using Modified Electrochemical Platforms

et al. 2022

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Water pollution is nowadays a global problem and the effective detection of pollutants is of fundamental importance. Herein, a facile, efficient, robust, and rapid (response time < 2 min) method for the determination of important quinone-based industrial pollutants such as hydroquinone and benzoquinone is reported. The recognition method is based on the use of screen-printed electrodes as sensing platforms, enhanced with carbon-based nanomaterials. The enhancement is achieved by modifying the working electrode of such platforms through highly sensitive membranes made of Single- or Multi-Walled Carbon Nanotubes (SWNTs and MWNTs) or by graphene nanoplatelets. The modified sensing platforms are first carefully morphologically and electrochemically characterized, whereupon they are tested in the detection of different pollutants (i.e., hydroquinone and benzoquinone) in water solution, by using both cyclic and square-wave voltammetry. In particular, the sensors based on film-deposited nanomaterials show good sensitivity with a limit of detection in the nanomolar range (0.04 and 0.07 μM for SWNT- and MWNT-modified SPEs, respectively) and a linear working range of 10 to 1000 ppb under optimal conditions. The results highlight the improved performance of these novel sensing platforms and the large-scale applicability of this method for other analytes (i.e., toxins, pollutants).

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Intrinsic electrochemical performance and precise control of surface porosity of graphene-modified electrodes using the drop-casting technique

Cited by 29 publications

References 31 publications

Bottom-up Electrosynthesis of Highly Active Tungsten Sulfide (WS_3–x) Films for Hydrogen Evolution

Bottom-up Electrosynthesis of Highly Active Tungsten Sulfide (WS_3–x) Films for Hydrogen Evolution

Interfacial Capacitance of Graphene Oxide Films Electrodes: Fundamental Studies on Electrolytes Interface Aiming (Bio)Sensing Applications

Sensitive Detection of Industrial Pollutants Using Modified Electrochemical Platforms

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Intrinsic electrochemical performance and precise control of surface porosity of graphene-modified electrodes using the drop-casting technique

Cited by 29 publications

References 31 publications

Bottom-up Electrosynthesis of Highly Active Tungsten Sulfide (WS3–x) Films for Hydrogen Evolution

Bottom-up Electrosynthesis of Highly Active Tungsten Sulfide (WS3–x) Films for Hydrogen Evolution

Interfacial Capacitance of Graphene Oxide Films Electrodes: Fundamental Studies on Electrolytes Interface Aiming (Bio)Sensing Applications

Sensitive Detection of Industrial Pollutants Using Modified Electrochemical Platforms

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Bottom-up Electrosynthesis of Highly Active Tungsten Sulfide (WS_3–x) Films for Hydrogen Evolution

Bottom-up Electrosynthesis of Highly Active Tungsten Sulfide (WS_3–x) Films for Hydrogen Evolution