Rhenium-Based Single-Atom Polymer-Brush Photocatalysts on Zeolite for Visible Light CO2 Conversion

• Published in: ACS applied engineering materials Vol. 3; no. 8; pp. 2308 - 2320
• Main Authors: Telegeiev, Igor, Youssef, Ali, Alboudone, Nibal, Lanel, Adrien, Lebedev, Oleg I., El Fallah, Jaafar, El-Roz, Mohamad
• Format: Journal Article
• Language: English
• Published: American Chemical Society 22.08.2025
• Subjects: bipyridine; photopolymerization; single-atom-catalyst; photocatalysis; CO2 reduction
• ISSN: 2771-9545; 2771-9545
• DOI: 10.1021/acsaenm.5c00190

Herein, we report a strategy for preparing polymer brushes of single-atom-based photocatalysts on the external surface of zeolite particles. The hybrid photocatalyst was prepared via the “on-surface” photopolymerization process of [2,2′-bipyridine]-4,4′-diyl diacrylate monomers (A2bpy) on a zeolite X (ZX) surface, postfunctionalized with a photoinitiator, and dispersed in the monomers solution. The polymer brush formed on the outer surface of the zeolite particles was successfully cofunctionalized with Ru­(bpy)3Cl2 and/or Re­(bpy)­(CO)3Cl, serving as the benchmark photosensitizer and photocatalyst, respectively. This process yielded a core–shell-like zeolite structure surrounded by a poly single-atom-based photocatalyst. The quantitative analyses of various samples, through advanced analytical techniques, demonstrate high yields of both ligand photopolymerization (>65%) and postbipyridine functionalization (>45%). The accessibility of the pores of the zeolite core is well preserved after both polymerization and complexation processes, facilitating reactant (e.g., H2O, CO2, HCO3 –) absorption and release. Absorption transient spectroscopy confirmed efficient Ru–Re charge transfer. The hybrid photocatalysts demonstrated a 5-fold increase in activity compared to the pure polymer counterpart (poly­[Re]). This enhanced performance is attributed to the affinity of the zeolite pores for CO2/carbonate adsorption and improved active sites accessibility. This study presents a cost-effective strategy for synthesizing versatile, recyclable materials and catalysts with potential applications in catalysis, 3D-printed nano-objects, multimetal assembled catalysts, mixed-matrix integrated membranes, and the immobilization of poly­(bpy) on solid supports for medical and (photo)­catalytic purposes.