Highly efficient Ag adorned HMTA assisted ZnO nanocomposite for rapid removal of emerging pollutants based on dangerous dyes

초록

Because of their durability and resistance to biodegradation, even very small concentrations of synthetic dyes in water are not recommended for human consumption and can have a negative impact on the transparency and aesthetics of water bodies. Semiconductor photocatalysis is one of the key solutions for color wastewater treatment. An efficient silver-loaded hexamethylenetetramine-assisted zinc oxide (HMTA-ZnO/Ag) photocatalyst was prepared via the solid-state dispersion technique. The creation of the wurtzite structure of ZnO and the cubic structure of Ag NPs is confirmed by the XRD patterns. The FT-IR analysis exposes the various vibration modes of the samples, whereas the PL analysis indicates three distinct bands of emission of the synthesized photocatalyst. FT-Raman spectra were obtained to study the various modes of the produced photocatalysts. The UV-Vis DRS absorption spectra show the difference in bandgap between unloaded and Ag-loaded HMTA-ZnO from 3 to 2.75 eV. The examination of FE-SEM morphologies revealed that the particles had non-uniform shapes. Further, analyzed by HR-TEM, metallic Ag was detected on the surface of ZnO and also proved by XPS examination through the Ag-loaded HMTA-ZnO photocatalyst. Photocatalytic activities were measured and compared for three azo dyes (Methylene Blue (MB), Reactive Red 120 (RR 120), and Acid Black 1 (AB 1)) under UV-A light irradiation with the help of UV-Vis spectrophotometer. The photocatalytic activity gets boosted when metallic nanoparticles of Ag are loaded on HMTA-ZnO surfaces which enables the dispersion of photogenerated pairs of electrons and holes. Since the addition of Ag onto HMTA-ZnO NPs (HMTA-ZnO/Ag), the photocatalytic activity has improved considerably.

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