Many parameters influence the photocatalytic production of H 2. Identifying and quantifying them is necessary for correct comparison of photocatalysts and right understanding of involved mechanism. In this work, we studied the photocatalytic dehydrogenation of isopropanol with titania-supported ruthenium disulfide. We studied the influence of seven parameters on the photocatalytic activity: the temperature, the composition of the reactive mixture, the mass of the photocatalyst, the flux and the energy of the incident photons, the co-catalyst loading and the nature of the support. Their influence was studied, not only on the rate of hydrogen production (or photon yield) but also on the apparent activation energy and on the pre-exponential factor, deduced from an Arrhenius law. The photon yield as a function of the co-catalyst loading show an optimum of activity. A 6.9 % photon yield was obtained at 0.84 wt% and = 3.65. The rate-determining step for the photocatalytic dehydrogenation of the isopropanol with RuS 2 /TiO 2 is, at optimal conditions, the electron transfer from TiO 2 to RuS 2. The latter is not favored because of the band diagrams of RuS 2 and TiO 2. The electron transfer can be optimized working with incident photons having a higher energy, thanks to a hot carrier effect observed in RuS 2 /TiO 2 .