P-015

Gabrielė Šarapajevaitė

gabriele.sarapajevaite@ftmc.lt

Jurga Juodkazytė,  Milda Petrulevičienė

Center for Physical Sciences and Technology (FTMC), Lithuania

Prospects of sustainably derived molybdenum disulfide as an electro(photo)catalyst

Molybdenum disulfide (MoS2) is a low-cost n-type semiconductor, characteristic of a band gap of 1.2-1.9 eV and a versatile structure that enables multifunctional properties crucial for various applications [1]. For example, photocatalytic/electrochemical properties of MoS2 can be effectively exploited to produce green hydrogen or to degrade organic wastewater pollutants [2].

Typically, hydrothermal synthesis of MoS2 involves using soluble sources of Mo(VI) and sulfur at a relatively high temperature and for extended duration in a synthetic organic-based surface modification and reducing medium [1]. In addition, the mentioned conditions are not energetically efficient and also may lead to emissions of toxic reagents or its decomposition products. Since most of the proposed synthetic pathways are based on low yield production in a toxic reagent’s environment, a greener approach to obtaining MoS2 is necessary for environmental sustainability.

In addition, the aim of this research was to develop a sustainable approach to synthesize MoS2 and to investigate its potential as a photo(electro)catalyst. For this reason, ascorbic acid was employed as a green reducing agent, which simultaneously was also used as a green surfactant. MoS2-based samples were synthesized in hydrothermal environment at a temperature of 180-220 °C for 8-12 h. Chemical and morphological composition was determined by analysis methods of X-ray diffraction, scanning electron microscopy and X-ray photoelectron spectroscopy. The particle size distribution of the samples was also measured, and the band gap of the synthesis products was determined by UV-visible spectroscopy. Lastly, electrochemical properties of samples were characterized by cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy.

The findings of this research have revealed that under the applied hydrothermal conditions, defect-rich 2H-MoS2 was formed, exhibiting strong photo(electro)chemical activity. Therefore, the proposed synthesis approach offers a sustainable method for producing MoS2 with promising properties for photocatalytic applications.

References:

[1] P. Phalswal, P.K. Khanna, H.-G. Rubahn, Y.K. Mishra, Nanostructured molybdenum dichalcogenides: a review, Mater Adv 3 (2022) 5672–5697.

[2]  R. Jiang, M. Xiao, H.-Y. Zhu, X. Zang, D.-X. Zhao, J.-Q. Zhu, Y.-K. Long, Q. Wang, Intriguing and boosting molybdenum sulfide (MoS2)-based materials for decontamination and purification of wastewater/seawater: An upgraded review, Sep Purif Technol (2024) 128063.