Constructing metallosalen poly(ionic liquid)s to boost photocatalytic CO2 reduction

Photocatalytic CO2 reduction to syngas has recently garnered substantial interest due to its mild reaction conditions, high safety, and environmental sustainability. However, the efficiency of syngas production remains relatively low. In this study, we have developed metallosalen-based poly(ionic liquid)s (PILs) to enhance syngas production, achieving one of the highest production rates recorded to date. The Co(Salen)-PIL demonstrates a syngas production rate of 168.1 mmol g−1 h−1, including a CO production rate of 69.3 mmol g−1 h−1, which is more than eight times higher than that of the best previously reported organic materials. Mechanistic investigations reveal that pyridine ions facilitate electron transfer from the heptazine light-harvester to the Co(Salen) active site. This study lays the groundwork for developing high-performance catalysts for photocatalytic syngas production.