Engineering Biotic–Abiotic Interfaces of Semi-artificial Photosynthetic Systems for Solar-Driven CO2 Conversion

Abstract Semi-artificial photosynthetic systems (SAPSs) integrate the superior light-responsive capabilities of semiconductors with the high selectivity of microbial biocatalysts, offering a pathway for CO2 mitigation and sustainable energy conversion. The performance of SAPSs is primarily constrained by limited CO2 enrichment, inefficient electron transfer, and the low added value of products. To address these challenges, material engineering strategies, including dimension regulation, surface functionalization, and band gap engineering, are employed to enhance CO2 enrichment, charge separation, and electron transfer. Meanwhile, microbial engineering further improves product selectivity through heterologous expression and enzyme engineering, enabling the biosynthesis of value-added chemicals. At the system level, interfacial coupling and electron-transfer mechanisms are systematically analyzed to elucidate electron transport pathways and guide interface optimization. Furthermore, a multidimensional performance evaluation framework is established to systematically compare representative SAPS combinations, C1–Cn product distribution, and solar-to-chemical conversion efficiency, which provides quantitative insights. The environmental influences of light, temperature, and others on biohybrid stability, and carbon-fixation performance are also critically discussed. Finally, future optimization perspectives at molecular level are presented from microbial carbon fixation to the engineering large-scale upgrading of SAPSs.