Bidirectional host-guest interactions promote selective photocatalytic CO2 reduction coupled with alcohol oxidation in aqueous solution

Existing artificial photosynthesis systems often underperform due to challenges in water oxidation and extensive photogenerated carrier transfer. Herein, we demonstrate that ss-cyclodextrin-decorated CdS nanocrystals (CdS-CD) can simultaneously anchor cobalt tetraphenyl porphyrin (CoTPP) catalysts and alcohol reductants onto CdS surfaces through bidirectional host-guest interactions between ss -CD and CoTPP/alcohol. This configuration ensures swift electron transfer from CdS to ss-CD bonded CoTPP, facilitating CO2 reduction to HCOOH. Results showcase a remarkable yield of 1610 mu mol g(-1) h(-1) and a 96.5% selectivity. Meanwhile, photogenerated holes in CdS are efficiently neutralized by ss-CD bonded furfuryl alcohol, achieving a furfural yield of 1567 mu mol g(-1) h(-1 )and > 99% selectivity. In contrast, the discrete CoTPP-CdS system achieved a HCOOH yield of only 306 mu mol g(-1) h(-1 )and a poor HCOOH selectivity of 46.4%. It was also observed that the CoTPP@CdS-CD system maintained high CO2-to-HCOOH conversion rates when using other alcohols as reductants.

Automated summary

In this study, it is demonstrated that ss-cyclodextrin-decorated CdS nanocrystals can effectively anchor cobalt tetraphenyl porphyrin (CoTPP) catalysts and alcohol reductants, achieving high yields and selectivity in artificial photosynthesis.