Tailoring the physicochemical properties of chemically deposited MoS₂ thin films for photocatalytic dye and TC degradation: effect of different cationic precursors

Precursor chemicals significantly impact the physicochemical properties of chemically deposited thin films. Herein, different cationic precursors such as ammonium molybdate (AM), molybdenum trioxide (MO) and sodium molybdate (NM) are used to deposit MoS₂ thin films using chemical bath deposition (CBD). Their effect on film formation, physicochemical properties and photocatalytic performance is investigated. The MoS₂ thin films display a hexagonal phase of MoS₂ with nanocrystalline characteristics. All MoS₂ thin films display nanospherical morphology with an optical bandgap of 1.6 eV. The MoS₂ thin film deposited using NM precursor shows a higher surface area of 31 m²g⁻¹ than that of the MoS₂ thin films deposited using AM (28 m²g⁻¹) and MO (22 m²g⁻¹) precursors. All MoS₂ thin films are highly active for the photocatalytic degradation of target organic molecules like methylene blue (MB), rhodamine B (RhB) and tetracycline hydrochloride (TC) antibiotic. Among all, the MoS₂ thin film deposited using NM demonstrated excellent photocatalytic performance by degrading 84, 71 and 74% of RhB, MB and TC in 2 h of visible light irradiation with a pseudo-first-order rate constant of 0.038, 0.033 and 0.026 min⁻¹, respectively. This work shows that MoS₂ thin films deposited using NM exhibit better photocatalytic performance than those deposited using AM and MO precursors.