Spin-Polarized Chiral ZnIn2S4 for Targeted Solar-Driven CO2 Reduction to Acetic Acid.

Acetic acid represents a pivotal target for CO2 reduction due to its dual function as a carbon-utilization product and industrial feedstock. However, photocatalytic CO2 reduction (PCCR) to acetic acid typically suffers from low acetic acid yields and selectivity, constrained by competing reactions from ethanol and inefficient C-C coupling. Herein, we report a chiral mesostructured ZnIn2S4 (CMZI) photocatalyst that achieves a remarkable acetic acid yield of 962 µmol g-1 h-1 with a high selectivity of 97.3%. This performance stems from synergistic chirality-induced spin polarization and sulfur site catalysis. Spin polarization stabilizes the triplet OCCO intermediate to enhance C-C coupling, while sulfur sites on ZnIn2S4 {102} facets thermodynamically and kinetically favor acetic acid formation. This work offers critical insights into catalytic strategies of the efficient synthesis of high-value multicarbon products and expanding the variety of synthetic products from CO2 reduction.