太阳能光催化分解水气泡动力学研究进展

The bubble dynamics in solar photocatalytic hydrogen production involves the interaction between multiple physical fields and photocatalytic reactions, which is unique and more complicated than the classic bubble dynamics in the field of boiling heat exchange and water electrolysis. Based on the basic principle of photocatalytic water splitting, this paper reviews the research progress in the dynamics of bubble nucleation and growth on the catalyst surface and the regulation of bubble behavior. The scale and supersaturation of bubble nucleation for photocatalytic water splitting can be estimated by the classical nucleation theory, however, the information of bubble nucleation process with high spatial and temporal resolution cannot be obtained simultaneously yet due to the constraints of existing testing methods. For the bubble growth on the catalyst surface, it can usually be described by three mechanisms: inertia control, diffusion control and chemical reaction control, and the key to determine the bubble growth control mechanism is the relative size of the effective reaction surface to the bubble size. The negative impact of bubble coverage on the photocatalytic reaction system can be effectively reduced by directional regulation of bubble behavior, including passive regulation methods based on the addition of surfactants and modulation of catalyst surface structure and wettability, and active regulation methods based on the application of external flow field, acoustic field, magnetic field and periodic illumination. The primary challenges of current research arc to reveal the mechanisms of interphase interactions and energy-mass transport under the action of complex physical fields, thereby providing guidance for future low-cost and efficient solar photocatalytic hydrogen production applications.