One-Step Encapsulation of Sulfonated Palladium Phthalocyanine in ZIF-8 for Photocatalytic Degradation of Organic Pollutants

Photocatalysis driven by the visible light of solar energy has received considerable attention in the field of environmental remediation and clean energy production. In this work, monomeric sulfonated palladium phthalocyanine (PdPcS) was encapsulated in zeolitic imidazolate frameworks-8 (ZIF-8) crystals (denoted PdPcS@ZIF-8) through electrostatic interaction in the ammonia system, while their photocatalytic activity was well-maintained together with the structural regularity of ZIF-8 crystals. For comparison, a PdPcS/ZIF-8 sample was obtained from the traditional impregnation method. The ¹³C NMR and UV-DRS spectra confirmed the difference between PdPcS@ZIF-8 and PdPcS/ZIF-8 in terms of the chemical environment effect for PdPcS. Under visible light, the optimal PdPcS@ZIF-8 catalyst achieved complete degradation of 0.1 mM bisphenol A in 120 min. It also exhibited excellent stability, retaining 81.5% activity after four cycles, far outperforming the impregnated sample (32.5%) due to effective encapsulation preventing PdPcS leaching. This versatile one-step synthetic strategy is expected to be useful for designing novel macromolecules@MOF composite materials.