Surfactant-mediated modulation of morphology and charge transfer dynamics in tungsten oxide nanoparticles

Abstract

Tungsten Oxide (WO3) is a well-known transition metal oxide which exhibits non-toxicity and stability in its nanoparticle form. It is a potential candidate for a variety of applications due to its low cost and facile synthesis process. In the present work, WO3 nanoparticles were synthesized via facile acid-coprecipitation method to explore the effect of surfactants on the morphology of WO3 nanoparticles and thus, on its structural, optical and electrochemical properties. The morphology analysis revealed the formation of spherical nanoparticles in the absence of any surfactant while nanoflakes and nanosheets were observed in the presence of cetyltrimethylammonium bromide (CTAB) and polyethylene glycol (PEG), respectively. Moreover, the presence of surfactants was found to influence the crystallinity state of the samples. The different morphologies exhibited optical band gap of 2.2-2.7 eV as analyzed by UV-Vis spectroscopy along with other optical properties like absorbance range and refractive index. The electrochemical properties of the samples were studied by employing potentio electrochemical impedance spectroscopy (PEIS) and cyclic voltammetry (CV) techniques. CV analysis revealed the diffusion-controlled behavior of the samples which may be suitable for photovoltaic applications. Furthermore, impedance study showed the presence of Warburg impedance which indicates that there is an infinite layer of excitons on the surface of thin film, further suggesting WO3 as a prominent material for solar cell applications. The incorporation of surfactants resulted in the reduction of charge transfer resistance indicating more efficient charge transfer process.

Enhanced Electrochemical Performance and Charge-Transfer Dynamics of 2D MoS2/WO3 Nanocomposites for Futuristic Energy Applications

“…Moreover, a few TMOs show excellent photocatalytic properties enabling the generation of electron–hole pairs. − An excellent TMO with a number of intriguing characteristics is tungsten oxide (WO 3 ). The exceptional properties of WO 3 as discussed in our earlier works , make it a versatile material for a variety of applications.…”

“…reported a vertical heterostructure formed by monolayer CVD-grown MoS 2 and WO 3 films. , The morphology of the particles depends on the synthesis technique employed and the parameters used during the synthesis. Kumar et al reported the synthesis of WO 3 nanostructures via facile acid coprecipitation method which we have used in the present work for the preparation of nanocomposites owing to the advantages of this methods as reported by Kumar et al Most of the previous research has primarily focused on applications related to wastewater management, water splitting and gas sensors. − The composite structures have previously shown excellent photocatalytic activity, permit effective charge separation, and encourage light absorption across a wider spectrum …”

Fabrication of tunable band gap carbon based zinc nanocomposites for enhanced capacitive behaviour

“…The presence of Warburg impedance confirms that the exchange of ions between the electrolyte and thin film is happening at a higher rate creating a infinite layer of electron on the surface of thin film. The plot for CSD shown in figure 10(a) suggests that CSD is a potential candidate for solar cell applications but it cannot be used in such applications The Bode plots of the as synthesized samples have also been plotted which exhibits the change in impedance and phase angle with log frequency [63]. The Bode plot shows stability in system setup.…”

Electrochemical analysis of thermally treated two dimensional zinc sulphide hexagonal nano-sheets with reduced band gap

“…T W-H plots [as shown in figures 4(a) and (b)] are obtained taking βcosθ and 4sinθ as y and x-axis respectively. The slope of the plot gives the value of the strain present in the as-synthesized samples, whereas intercept of these plots is used to estimate the crystallite size of the samples following eqution-5 [44].…”

“…Figure 12(a) depicts the Nyquist plot for hexagonal ZnS. The PEIS system is operated in a frequency range of 7 MHz to 10 mHz [44,58]. The system shows high gain margin as the system remains stable for both higher and lower frequency range.…”