Amorphous MoS₂ thin films have been prepared by thermal deposition on glass, quartz, and FTO substrates and investigated by UV-VIS – NIR spectroscopy. The type of substrate has a minor impact on the film's spectral absorption and band gap values. The investigation of MB – dye degradation by MoS₂ catalyst under UV – irradiation demonstrates high efficiency of 86%. MoS₂ films deposited on glass substrates have been experienced as CO₂, HCl, and I₂ gas sensors. The films revealed promises for CO₂ sensing at high temperatures (T 300 ) in terms of relatively good response (  and moderate recovery of 12 min. Besides, MoS₂ films revealed a quick response within 1 min for both HCl and I₂ gases, while their entire recovery needs a time period longer than one hour.