Light-Driven Microbe−Nanomaterial Hybrids for CO ₂ Conversion: Innovations in Synthesis, Materials, Microbial Engineering, and Reactor Design

Solar-driven microbe−nanomaterial hybrids (MNHs) offer a transformative pathway for carbon neutrality by synergizing the broad-spectrum light-harvesting capabilities of inorganic photocatalysts with the unparalleled catalytic specificity of living cells. However, translating these systems from laboratory curiosities to scalable technologies requires a rigorous understanding of the biotic−abiotic interface. This review provides a comprehensive framework bridging the physical chemistry of photocatalytic electron transfer with microbial metabolic engineering. We critically examine how spatial architectures, spanning extracellular, periplasmic, and cytoplasmic integrations, dictate the thermodynamic driving forces and kinetic bottlenecks of photocatalyst-to-microbe charge transfer. By synthesizing recent advancements in next-generation photocatalytic nanomaterials (including single-atom catalysts, Z-scheme architectures, and perovskites) with programmable microbial chassis and synthetic CO2 fixation pathways, we establish a rational basis for hybrid optimization. Furthermore, we evaluate emerging assembly strategies and novel reactor geometries, such as optical fiber scaffolds and nanoconfined hydrogels, designed to overcome gas−liquid mass-transfer limitations and maximize the photon economy of the embedded photocatalysts. Finally, we outline a strategic roadmap to overcome the persistent challenges of photocatalyst degradation, kinetic mismatch, and biosafety, advocating for standardized benchmarking and intrinsic biocontainment principles to accelerate the deployment of MNHs in sustainable chemical manufacturing.