Environmental remediation of dual-model-pollutants in multi-water sources via controlled pyrolysis of ZIF-67-derived Co3O4/g-CN heterojunction: Real-world photocatalytic application.

Abstract

In this study, a novel zeolitic imidazolate framework (ZIF-67)-derived Co₃O₄ and graphitic carbon nitride (g-CN) based nanohybrid heterojunction (Co₃O₄/g-CN) was synthesized through a controlled thermal treatment process for highly efficient and stable photocatalytic environmental remediation in real-world water matrices. The thermal conversion of ZIF-67 into highly porous Co₃O₄ with retained structural integrity, coupled with the strategic incorporation of g-CN, facilitated the formation of a heterojunction that significantly enhanced charge carrier separation and mobility. Under mineralized water conditions, the Co₃O₄/g-CN (1:5) nanohybrid achieved outstanding photocatalytic degradation efficiencies of 99 % for dinoseb and 96 % for methyl orange within 75 min, with apparent rate constants of 0.0389 min^-1 and 0.0311 min^-1, respectively, an order of magnitude higher than the individual components. Moreover, mineralization efficiencies reached 73 % for dinoseb and 69 % for methyl orange within 150 min, as verified by gas chromatography-mass spectrometry analysis of transformation products. Structural and morphological stability, after repeated photocatalytic cyclic runs, was confirmed through X-ray diffraction and microscopic analyses, underscoring the robust nature of the nanohybrid. Lastly, we designed a type-II mechanistic heterojunction system, accountable for enhanced photocatalytic performance over Co₃O₄/g-CN nanohybrid. Ultimately, the synergistic interaction within the heterojunction sets a benchmark for advancing sustainable water treatment technologies, offering a scalable and effective solution to environmental pollution.