Interfacial engineering on hierarchical ZrO nanozyme realizes efficient CO photoreduction.

Designing and fabricating nanozymes with photoactivity for CO reduction poses a significant challenge. Here, a hierarchically structured ZFs-tpyNi heterojunction nanozyme, comprising a terpyridine-based Ni complex supported on ZrO nanoframes, has been created through an interfacial engineering strategy for efficient CO reduction under visible light. Due to its unique structural and compositional advantages, ZFs-tpyNi demonstrates superior photocatalytic CO-to-CO conversion compared to its counterpart of ZFs and tpyNi, achieving a CO yield of 18.2 µmol and a selectivity of 92.4 % with a high apparent quantum efficiency of 0.96 % in 3 h. These innovative catalysts also show excellent durability for at least eight cycles without a loss in performance, maintaining a remarkable structural stability with no obvious collapse of its framework and morphology. Systematic investigations reveal that ZFs-tpyNi heterostructures exhibit a high specific surface area advantageous for the effective loading of tpyNi and exposure of active sites. The robust ZFs framework, characterized by extensive porosity, prevents nanoparticle agglomeration and accelerates mass transfer during catalysis. Additionally, the spatially heterogeneous interface enables precise modulation of band alignment and bandgap dynamics in nanozymes, enhancing light absorption and promoting the generation and separation of photogenerated charge carriers. Consequently, the nanozyme demonstrates enhanced CO adsorption and activation capabilities, leading to improved selectivity of catalytic products. This work aims at highlight the role of nanozyme catalysts in sustainable energy production.