Artificial Photosynthesis Over Ultrasonically Engineered SCN@Fe 3 O 4 Magnetic Nanorods for Selective Carboxylation Reaction

One of the most difficult challenges of this century is the quick conversion of anthropogenic carbon dioxide (CO 2 ) into value‐added solar chemicals/fuels. The best method for transforming CO 2 into beneficial compounds like glucose and oxygen is natural photosynthesis. In this context, herein, an artificial photosynthesis over ultrasonically engineered SCN@Fe 3 O 4 magnetic nanorods was designed for a selective carboxylation reaction (CO 2 ‐to‐formic acid production). The SCN@Fe 3 O 4 magnetic nanorods were employed as an efficient visible light–responsive photocatalyst for the regeneration of NADH (nicotinamide adenine dinucleotide hydrogenase) from NAD + (nicotinamide adenine dinucleotide), where NADH serves as the biologically active hydrogen carrier. Under visible light irradiation, the optimized photocatalytic system achieved an in situ NADH regeneration (74.49%), which subsequently promoted the enzymatic reduction of CO 2 ‐to‐HCOOH using formate dehydrogenase (FDH). The system produced HCOOH (170.70 µM) under optimized conditions in a phosphate buffer medium containing NAD + , Rh‐based electron mediator, and triethanolamine (TEOA) as a sacrificial agent. The greater yield and high efficiency attained here suggest a sustainable and high‐throughput approach to useful enzymatic applications.