Optimizing Adsorption‐Redox Sites and Charge Transfer of Ternary Polymer Photocatalyst with P─N Linkage for CO₂ Conversion Coupled with Antibiotics Removal

Abstract The rational design of bifunctional photocatalysts with high adsorption and enrichment characteristics and excellent photocatalytic redox activity is an effective way to address environmental pollution and energy shortage crisis. In this study, cyclophosphazene‐derived porous organic polymer (PCPD) microspheres with P─N linkage are coated with graphene oxide (GO) and loaded with Ag⁰ nanoparticles (NPs) to prepare covalently bonded xAg‐rGO/PCPD composites. The catalyst with the highest specific surface area (denoted as 2.5Ag‐rGO/PCPD) shows excellent adsorption capacity for fluoroquinolone antibiotics, removing 96.2% of ciprofloxacin (CIP) through adsorption. By applying the catalyst with the best photocatalytic redox activity (denoted as 5Ag‐rGO/PCPD), 82.97% of refractory sulfonamide antibiotics are removed through adsorption‐degradation, and 635.3 µmol g⁻¹ of CO and 162.3 µmol g⁻¹ of CH₄ are generated as products of CO₂ photoreduction alone. Among the co‐catalytic systems, the highest CO yield of 9.16 µmol g⁻¹ is obtained by coupling CO₂ reduction with levofloxacin (LVX) degradation to harness the electron‐donating power of the pollutant molecule. This study is expected to provide useful guidance for the rational design of bifunctional photocatalysts.