Controlled Growth of WO3 Pyramidal Thin Film via Hot-Filament Chemical Vapor Deposition: Electrochemical Detection of Ethylenediamine

Abstract

In this work, the structural, optical, morphological, and sensing features of tungsten oxide (WO3) thin film deposited on a silicon substrate via hot-filament chemical vapor deposition (HFCVD) are described. The experimental characterization tools, such as X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), ultraviolet-visible (UV-Vis), and Fourier transform infra-red (FTIR) spectroscopies, etc., were used to determine the properties of WO3 NPys thin films. The grown WO3 thin film illustrated closely packed porous pyramidal nanostructures (NPys) of improved grain size properties. The diffraction analysis revealed (100) and (200) of WO3 phases, suggesting the classic monoclinic crystal WO3 structure. HFCVD grown WO3 NPys thin film was employed as electro-active electrode for detecting ethylenediamine in 10 mL of 0.1 M phosphate buffer solution (PBS) by varying the ethylenediamine concentrations from 10 μM to 200 μM at room temperature. With a detection of limit (LOD) of ~9.56 μM, and a quick reaction time (10 s), the constructed chemical sensor achieved a high sensitivity of ~161.33 μA μM−1 cm−2. The durability test displayed an excellent stability of electrochemical sensor by maintaining over 90% sensitivity after 4 weeks of operation. This work provides a strategy for a facile preparation of WO3 NPys thin film electrode for sensor applications.

Fabrication of Tungsten Oxide Nanowalls through HFCVD for Improved Electrochemical Detection of Methylamine

“…These peaks usually occur due to the transfer of electrons displaying, the oxidation peak as a result of electron-losing behavior and the reduction peak occurs due to the electron-gaining behavior. In our work, the detection of methylamine by the HFCVD-grown WO3 NW thin-film electrode exhibits efficient electro chemical sensing behavior, which might be due to the high conductivity [33] and large surface area [63] of WO3 NW thin films. From linear sweep voltammetry,…”

“…This result suggests that HFCVD-grown WO 3 NWs show effective sensing capabilities in the detection of methylamine [65]. To examine the sensitivity of HFCVD-grown WO3 NW thin-film-based electrodes, Figure 7a shows the current vs. concentration calibration curve [33]. Herein, the current increases linearly with an increase in analyte concentration.…”

“…The performance of HFCVD-grown WO3 NW thin-film-based sensor is compared to other reported sensors [67][68][69][70][71], as shown in Table 1. To examine the sensitivity of HFCVD-grown WO 3 NW thin-film-based electrodes, Figure 7a shows the current vs. concentration calibration curve [33]. Herein, the current increases linearly with an increase in analyte concentration.…”

“…As shown in Figure 8, oxygen species adhere to the surface of WO 3 NW thin films grown through the HFCVD process. The HFCVD-grown WO 3 NW thin film shows n-type semiconducting behavior [33]. Due to the nature of WO 3 thin films, electrons in the conduction band tend to bond with the surface area of WO 3 thin films.…”

“…Thus, it is crucial to monitor the presence of methylamine to ensure safety and prevent potential accidents or exposures [32]. In this regard, electrochemical detection methods can provide real-time detection and monitoring [33] of methylamine, allowing for prompt action to mitigate any risks. In particular, the chemical sensing methods enable the detection and quantification of methylamine in environmental samples [34], helping to identify potential pollution sources and assess the impact on the environment [35,36].…”