In situ engineering 2D/3D CuCo2S4@Co3O4 heterojunction for sensing and photocatalytic degradation of diclofenac sodium in environmental water

Abstract

Accurate determination and rapid degradation of organic pollutants are essential works in environmental improvement. Herein, the CuCo₂S₄@Co₃O₄ heterojunction with fascinating 2D-on-3D hierarchical nanoflowers architecture and highly distributed interface sites were successfully synthesized by CuCo-LDH topological transformation combine with in situ exterior sulfurization strategy. The 2D-on-3D nanoflowers architecture could improve light harvesting ability, provide large surface area, open channels and abundant edge sites. In particular, the intensive M-O-S-M heterojunction interface not only promote the photoexcited charge shuttling but provide abundant interface sites to enhance catalytic activity. As expected, the photocatalytic degradation rate of diclofenac sodium (DCF) on CuCo₂S₄@Co₃O₄ was approximately 100% within 30 min under 300 W mercury lamp, which was 1.28 times and 1.45 times higher than that of CuCo-LDH and CuCo₂O₄. The degradation rate for real samples were more than 80%, the mineralization rate was 90%, and the biological toxicity of degradation products decreased significantly. Furthermore, a novel photoelectrochemistry (PEC) sensor with CuCo₂S₄@Co₃O₄ as a photoanode was successfully constructed for directly sensing DCF, showing a wide linear range and satisfactory detection limit. The results indicate that the CuCo₂S₄@Co₃O₄ possess dual-functional peculiarity, hold vast potential for sensing and degradation environmental pollutants in wastewater.