MOF-Derived ZnSe&CoSe2@N-Doped Carbon/g-C3N4 for Efficient Photodegradation of Organic Dyes

Abstract

A highly efficient heterostructured photocatalyst was synthesized using a dual metal-organic framework (MOF)-derived method, succeeded by carbonization, selenization, and hydrothermal hybridization with g-C₃N₄, referred to as ZnSe&CoSe₂@N-doped carbon/g-C₃N₄. The structural, optical, textural, morphological, and electrochemical properties were examined using XRD, FT-IR, DRS, surface area analysis, TEM/HR-TEM, SEM images, EDX mapping, photoluminescence spectroscopy, cyclic voltammetry, chronoamperometry, and Mott–Schottky analysis. The optimized 3 wt% ZnSe&CoSe₂@N-doped C/g-C₃N₄ composite exhibited superior photocatalytic degradation of methylene blue (MB) and rhodamine B (RhB), in contrast to g-C₃N₄ and ZnSe&CoSe₂@N-doped C. The heightened activity is attributed to effective heterojunction creation, enhanced charge transfer, less electron-hole recombination, and improved light absorption. Radical-trapping experiments indicated that hydroxyl radicals were the reactive species involved in dye degradation, whereas electrochemical assessments validated improved charge separation and interfacial carrier mobility. The addition of H₂O₂ enhanced the degradation efficiency to over 97% and reduced the degradation time (< 20 min) by facilitating the generation of •OH radicals.