Synergistic effect of ZnO/Ag2O@g-C3N4 based nanocomposites embedded in carrageenan matrix for dye degradation in water

• Published in: Heliyon Vol. 10; no. 11; p. e31109
• Main Authors: Mamba, Feziwe B., Mbuli, Bhekani S., Ramontja, James
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 15-06-2024; Elsevier
• Subjects: Carrageenan; Graphitic carbon nitride; Nanocomposite; Nanomaterial; Photocatalysis; Visible light; Visible light; Nanocomposite; Carrageenan; Nanomaterial; Photocatalysis; Graphitic carbon nitride
• ISSN: 2405-8440; 2405-8440
• DOI: 10.1016/j.heliyon.2024.e31109

This research achieved success by synthesizing innovative nanocomposite composed of zinc oxide (ZnO), graphitic carbon nitride (g-C3N4) and silver oxide (Ag2O) nanomaterials incorporated into a carrageenan matrix, thus creating an environmentally friendly and stable support structure. The synthesis process involved hydrothermal and chemical precipitation methods to create photocatalytic g-C3N4, ZnO, and Ag2O nanocomposites. The success is evident through the characterization results, which unveiled distinctive peaks corresponding to Zn–O (590-404 cm−1) and Ag–O (2072 cm−1) stretching in the Fourier transform infrared (FTIR) and X-ray diffraction (XRD) analyses, conclusively confirming the successful synthesis of g-C3N4, ZnO, Ag2O, and their respective nanocomposites. Further validation through a scanning electron microscope coupled with an energy dispersive spectrometer (SEM-EDX) and elemental mapping affirmed the presence of Zn, O, Ag, C, and N. Additionally, transmission electron microscope (TEM) imaging unveiled the nanosheet morphology of g-C3N4, the nanorod structure of ZnO, and the spherical form of Ag2O nanomaterials. ZnO and Ag2O nanomaterials demonstrated a consistent 10–20 nm size range. To underscore their ability to harness visible light, the nanomaterials were excited at 380 nm, emitting visible light emission within the 400–450 nm range. The synthesized nanocomposites showcased outstanding adsorption and photocatalytic properties, achieving efficiency ranging from 80 % to 98 %, attributed to the synergistic interactions between the various components. These findings culminate in a confirmation of the research's success, validating the exceptional potential of these nanocomposites for various applications.
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•Statement of Novelty.•Novel g-C3N4, ZnO, and Ag2O and their nanocomposites incorporated into carrageenan were prepared and demonstrated improved photocatalysis behavior, with the carrageenan acting as a support of the nanomaterials.•Modified carrageenan nanocomposites demonstrated high dye adsorption capacity, leading to high photocatalysis efficiency under visible light.•Synthesis of photocatalytic g-C3N4, ZnO, Ag2O and their nanocomposites.•Incorporation of g-C3N4, ZnO, Ag2O and their nanocomposites into carrageenan.•Photocatalytic nanocomposites formed have a particle size of 10–20 nm and a band gap of less than 3.3 eV.•The as-synthesized nanocomposites are efficient visible light active photocatalysts.•Degradation of Congo red, methylene blue, methyl violet, and methylene green by visible light photocatalysis.