Photocatalysis is an effective way to utilize solar energy to produce hydrogen from water. Au/TiO2 nanoparticles (NPs) have a better performance in photocatalytic hydrogen generation because of the localized surface plasmon resonance (LSPR) effect of Au/TiO2 NPs. In the photocatalytic hydrogen generation experiments, it was found that light intensity plays a key role in the photocatalytic reaction rate of Au/TiO2 NPs. At a light intensity of 0-7 kW/m(2), the reaction rate has a super-linear law dependence on the light intensity (Rate proportional to Intensity(n), with n > 1). However, at a light intensity of 7-9 kW/m(2), the dependency becomes sub-linear (n < 1). This means that the increase rate of photocatalytic rate is smaller than that of light intensity when the light intensity exceeds 7 kW/m(2). In addition, the finite element method (FEM) was utilized to further elucidate the role of light intensity by calculating the absorption power and nearfield intensity mapping of a Au/TiO2 nanoparticle. The variation trend of the calculated total absorption power agrees with the photocatalytic experimental results for different light intensities. These results shed light on the utilization of concentrated solar photocatalysis to increase the solar-to-hydrogen performance of Au/TiO2 NPs. (C) 2020 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.