In this study, the influence of hydrothermal reaction temperatures on V₂O₅synthesized via a green facile mild hydrothermal method at six different reaction temperatures ranging from 100 to 200 °C, at steps of 20 °C and the physical properties the synthesized samples have been investigated. The x-ray diffraction pattern confirms the stable orthorhombic crystal structure of the synthesized samples at all reaction temperatures. The scanning electron microscopy and transmission electron microscopy images demonstrate the particle-like morphology, and these characterizations affirmed that the particles’ size became larger with the increase in the reaction temperatures. To study the functional groups, Fourier-transform infrared investigation has been employed. The bandgap of the synthesized samples has been estimated using UV-vis diffuse reflectance spectra and was found to vary from 2.08 to 2.15 eV, which implies their suitability for absorbing a significant amount of visible light. The photocatalysis of methylene blue with synthesized samples has been carried out to investigate the photocatalytic efficiency. Pure V₂O₅ synthesized at a lower reaction temperature (100 °C) possesses a lower bandgap and, accordingly, higher photocatalytic efficiency.

Hydrothermally synthesized Mixed-phase MoS₂ (1T@2H-MoS₂), with sulfur vacancies, enables rapid (7 s) and selective NH₃ sensing (2–100 ppm) at 20 °C, overcoming MoS₂’s insulating limits and highlighting potential for industrial safety monitoring.