Artificial Light-Driven Ion Pumps.

Nature's molecular machinery has long provided inspiration for the development of functional materials, with natural ion pumps exemplifying the efficient conversion of solar energy into directional ion transport. This process is crucial for cellular signaling, bioenergy conversion, and photosynthesis. Motivated by these biological systems, artificial light-driven ion pumps have emerged as transformative technologies for sustainable energy harvesting, desalination, and bioelectronic innovations. This review categorizes synthetic light-driven ion pumps into two primary mechanistic paradigms: (1) photoelectric-driven transport, which leverages photoinduced charge separation in semiconductor structures, and (2) molecular phototransduction, which utilizes light-induced isomerization or conformational changes in photoactive molecules. For each paradigm, we trace their biomimetic origins to natural ion transport mechanisms, followed by a detailed analysis of design strategies, operational principles, and material innovations. These innovations range from dynamic photoresponsive molecules and semiconductors to semiconductor heterostructures, all of which enable precise control over ion selectivity, flux, and energy conversion in a spatiotemporal manner. Finally, we discuss the emerging applications of light-driven ion pumps and the remaining challenges for their practical implementation.