Interfacial Microenvironment Modulation Enhancing Electron Transfer between Quasi-MOFs and Defective Semiconductor Arrays for Enhanced Photocatalytic Sterilization

Interfacial electron transfer between an inorganic semiconductor and a metal-organic framework (MOF) is the key to photocatalysis in a composite photocatalytic system. The construction of structural defects in a single semiconductor or MOF has been regarded as an effective method for enhancing its photocatalytic performance. However, how the microenvironment modulation of photocatalytic sites between defective semiconductors and defective MOFs (quasi-MOFs) affects photocatalytic disinfection activity is worth studying. Herein, the integration of MOFs and semiconductors and their crystal defect construction is achieved by directly dropping ZIF-8 suspension onto the bismuth vanadate (BiVO₄) nanoarray and subsequently activating it through low-temperature (300 °C) calcination under an N₂ atmosphere. Compared with the original BiVO₄ nanoarray, defective BiVO₄ nanoarray (BiVO₄-N₂), and BiVO₄-ZIF-8 nanoarray, (BiVO₄-ZIF-8)-N₂ exhibits enhanced photocatalytic disinfection activity (6.63 log₁₀ CFU mL^-1 after 4 h of simulated sunlight irradiation) due to its improved sluggish kinetics of electron transfer. In situ irradiated operando near-ambient pressure XPS (NAP-XPS) confirms its interfacial electron transfer, which can greatly modulate the microenvironment of the photocatalytic site and thus lead to efficient photocatalysis. This work presents a simple strategy to adjust the microenvironment of the photocatalytic sites between ZIF-8 and semiconductors to optimize photocatalytic bactericidal performance.