A study has prepared Mo doped violet tungsten oxide (Mo-W18O49) by hydrothermal method, which can be used as the catalyst in manufacturing hydrogen with a very high activity. This is because the doping of molybdenum (Mo) increases the active sites of catalyst, since the approximate 3D microstructure composed of one-dimensional nanowire can not only help electronic transmission, but also further improve the interfacial charge transfer rate, thus to improve the activity of the catalyst to produce hydrogen.
In theory, the gibbs free energy of Mo doped violet tungsten oxide is similar to that of Pt, which also suggests that Mo-W18O49 has a very high activity. After the Mo doping, the changes of electrons and geometry will also affect the absorbing activity of hydrogen, thus to show an excellent electrochemical activity. In addition, studies have shown that 10% of molybdenum doping amount will make the VTO of large electrochemical activity of specific surface area, this is because the increase in the active site and in the mixed structure improve electron transfer rate to achieve a balance. Electrochemical impedance spectra shows that Mo-W18O49 can effectively reduce the charge conduction resistance, and increase the electrical conduction rate, accelerate the hydrogen produced speed, thereby to make Mo-W18O49 catalyst has excellent catalytic activity.
In the picture above, the red balls represent active sites, and we can see that after Mo doped, violet tungsten oxide has more active sites, which is to say it has more reaction sites.