Lattice Boltzmann method (LBM) is an alternative to conventional CFD to capture the detailed activities of the transport processes at microscale. Here LBM is used to model the hydrogen production by splitting water by incident sunlight over water covered Si-nanorods. The purpose of this study is, by a 3D microscale model, to investigate the transport and the formation of the hydrogen bubbles by electrochemical reactions. An ordered array of nanorods is created where each rod is 10 μm high and 10 nm in diameter. The 3D model is simulated using parallel computing with the program Palabos. A multicomponent reaction-advection-diffusion transport for 3 components is analyzed with electrochemical reactions and this process is further coupled with the momentum transport.
It has here been shown that LBM can be used to evaluate the microscale effect of electrochemical reactions on the transport processes. An increased Bond number increase the bubble flow through the nanorod domain. A decreased contact angle facilitates the disconnection of the bubble to the nanorod at the top surface. The collection of the hydrogen bubbles at the top surface of the nanorods will be facilitated by an easy disconnection of the bubbles.