Efficient Photoelectron Capture by Ni Decoration in Methanosarcina barkeri-CdS Biohybrids for Enhanced Photocatalytic CO(2)-to-CH(4) Conversion

Semi-artificial photosynthesis (biohybrid) provides an intriguing opportunity for efficient CO(2)-to-CH(4) conversion. However, creating a desirable semiconductor in biohybrids remains a great challenge. Here, by doping Ni into CdS nanoparticles, we have successfully developed the Methanosarcina barkeri-Ni:CdS biohybrids. The CH(4) yield by the M. barkeri-Ni((0.75%)):CdS biohybrids was approximately 250% higher than that by the M. barkeri-CdS biohybrids. The suitable Ni dopants serve as an effective electron sink, which accelerates the photoelectron transfer in biohybrids. In addition, Ni doping changes the metabolic status of M. barkeri and results in a higher expression of a series of proteins for electron transfer, energy conversion, and CO(2) fixation. These increased proteins can promote the photoelectron capture by M. barkeri and injection into cells, which trigger a higher intracellular reduction potential to drive the reduction of CO(2) to CH(4). Our discovery will offer a promising strategy for the optimization of biohybrids in the solar-to-chemical conversion.