Engineered Cu3P–ZnWO4 heterojunction integrated with porous polymer monolithic template for enhanced photocatalytic degradation of organic pollutants

The strategic fabrication of efficient, renewable, and sustainable visible photon-responsive advanced heterogeneous photocatalysts is currently relevant for decontaminating pharmaceutical pollutants. Here, we report the fabrication of a unique Cu₃P-ZnWO₄ (CZ) heterojunction nanocomposite (NC) uniformly decorated onto a porous poly(EGDMA) monolith (PEM) template, which features a remarkable surface area, excellent structural integrity, and high porosity. Varying ratios of Cu₃P to that of ZnWO₄ reveal a sequence of Z-scheme heterostructured NCs, i.e., CZ-5, CZ-10, CZ-15, CZ-20, and CZ-25. The structurally engineered translucent PEM template and the CZ NCs decorated PEM are characterized by p-XRD, FT-IR, FE-SEM-EDAX, HR-TEM-SAED, VB-XPS, BET/BJH, UV-Vis-DRS, and PL analysis to confirm the formation of the desired photocatalyst with impressive structural and surface morphological features. The photocatalytic degradation efficiency shows that the CZ-20 NC-dispersed PEM (CZ-20@PEM) photocatalyst proffers robust photocatalytic performance for decontaminating moxifloxacin residues. Moreover, to determine the optimal conditions for fast and efficient photocatalysis, the influence of various analytical parameters, including solution pH (2-9), photocatalyst dosage (10-150 mg), pollutant concentration (10-50 ppm), oxidizers (KBrO₃ & H₂O₂), and light intensities (150-300 W/m²) has been comprehensively studied. The CZ-20@PEM photocatalyst exhibits ≥ 99.4% moxifloxacin dissipation in ≤ 20 min, using 240 W/m² visible light intensity. Based on VB-XPS analysis and trapping experiments, a feasible photocatalytic mechanism was proposed to clarify the reactive species predominantly participating in the photocatalytic process. This work demonstrates an efficient and sustainable approach for removing moxifloxacin drug residues, underscoring the potential of nanocomposite-encapsulated polymer monoliths as a next-generation photocatalytic platform for future water treatment applications.