This research consists of three main parts: 1- Preparation of molybdenum oxide nanoparticles by flame method. 2- Investigating the optical, plasmonic and sensory properties of molybdenum oxide by hydrogen gas. 3. Investigation of photocatalytic and photo-thermal properties of molybdenum oxide. In the first part of this study, according to the performed work, the molybdenum oxide powder was prepared by flame synthesis method. This is performed by exposing a high purity molybdenum sheet in the vicinity of a hydrogen flame. By carrying out the process of hydrolyzing water and decomposing it into hydrogen (fuel) and oxygen (oxidizing material) and directing these two gases into the nozzle, a high-temperature and acceptable flame of hydrogen can be achieved. Brought up By analyzing the XRD, the phase of the compound is equivalent to monoclinic or ?. SEM analysis shows agglomerated and uecified structures. By analyzing TEM, we find out that the observed structures are nanoparticles with an approximate diameter of 5 nm, which are transformed into sheet structures by being regenerated by hydrogen gas in the presence of palladium catalyst. The absorption spectrum for the sample after synthesis does not show any particular behavior, and the sample is traarent. Meanwhile, with the recovery of a specimen with flame and hydrogen gas, the material exhibits an absorption peak of about 800 nm. Due to the properties of molybdenum oxide, it can be attributed to the plasmonic property of this material, which changes the intensity of the hydrogen concentration in the environment and can be used as a sensor for measurement of concentration of hydrogen. In this study, by studying the light-catalytic properties of molybdenum oxide, it can be seen that this material can be a photo-catalyst candidate. By examining the photo-thermal properties of this substance with a pulsed laser (Nd: YAG 1064 nm), the temperature change of 45 ° for 900 seconds was recorded for this substance. Finally, we try to justify the observed properties based on the plasmonic model.
