Schottky-mediated porphyrin-metal-organic framework/Ti3C2-MXene heterojunction for water decontamination via photonic-thermal-enzyme synergistic catalysis

Abstract

The inherent limitations of single-modal photocatalytic systems in complex wastewater treatment motivate the development of multifunctional catalysts to overcome restricted reaction kinetics and narrow activation spectra. In this study, we engineered a photo-thermal-enzyme triply synergistic catalyst by constructing an interfacial Schottky junction between porphyrinic metal–organic frameworks (PCN-224) and Ti₃C₂-MXene via a solvothermal synthesis. Scanning electron microscopy unveiled that PCN-224 cubes were anchored onto MXene’s delaminated sheets. This design uniquely integrated three complementary merits, including high photothermal conversion efficiency endowed by MXene, high charge separation enabled by Schottky-junction, and enzyme-mimetic activity through PCN-224 integration. Mechanistic studies combining first principles calculations, photoelectrochemical characterization, and operando infrared thermography revealed that the Schottky-junction optimized carrier utilization while localized heating favored to reduce activation energy of water and oxygen. The enzymatic oxidation of 3,3′,5,5′-testhylbenzidine was employed to evidence the peroxidase-like activity of the PCN-224/Mxene. This optimized composite achieved 91.2 % tetracycline (50 mg/L) and 97.4 % Rhodamine B (50 mg/L) degradation within 60 min, alongside 99.99 % and 99.92 % inactivation of methicillin-resistant Staphylococcus aureus and Escherichia coli, respectively. This work establishes a paradigm for multimechanistic synergy in environmental catalysis, demonstrating how rational catalysis engineering can simultaneously leverage photonic, thermal, and enzymatic activation pathways to overcome fundamental limitations in conventional systems. The demonstrated approach provides a scalable strategy for advanced water treatment technologies requiring high efficiency under real-world conditions.