Enhancing Solar-to-Chemical Conversion through Tailoring Dimensions of Semiconductors in Biohybrid Systems

Abstract Integrating light-harvesting semiconductor materials with biocatalysts offers a promising approach for solar-power production of fuels and fine chemicals. Despite significant advances, the influence of materials’ dimensions on energy utilization efficiency and the involved photoelectron transfer pathways remains largely to be explored. Here, we investigated the effect of dimensionality on the energy conversion efficiency in semiconductor nanomaterial-based biohybrid systems. We found that the intracellularly localized 2D nanoplatelets, particularly with core-crown heterostructures, were more efficient in supplying energy for microbial chemical production than the lower-dimensional nanomaterials. The biohybrids possessing the 2D nanoplatelets exhibited a 2.69-fold increase in 2,3-butanediol (BDO) production yield and achieved 2.35% solar-to-chemical conversion efficiency. Based on metabolomic and transcriptomic analyses, we identified a novel thiamine pyrophosphate (TPP)-mediated pathway of energy generation from photoexcited electrons. Furthermore, the addition of TPP enhanced the BDO production of the biohybrids under illumination. Our results demonstrate the potential to increase the solar-to-chemical conversion efficiency of semiconductor biohybrids by tailoring the dimension of semiconductor nanomaterials and engineering the intracellular electron transfer and energy generation pathways. *Mingming Guo and Xinke Kong contributed equally to this work.