Enhanced Photocatalytic Degradation Of Congo Red Under Visible Light Illumination By Using Zn-Al-Co-Ldh@G-C(3)N4 Nanocomposite

In this study, the potential of layered double hydroxide (Zn-Co-Al) decorated with g-C3N4 (CN) as a novel nanocomposite for degradation of Congo red (CR) under ultrasonic irradiation was evaluated. Characterization studies including transmission electron microscopy, scanning electron microscopy, X-ray diffraction, Brunauer-Emmett-Teller, Fourier-transform infrared spectroscopy and ultraviolet-visible diffuse reflectance spectroscopy (UV-Visible DRS) were conducted to study the structure of synthesized nanocomposite. Such characteristics as an open hierarchical structure comprised of intertwined CN and Zn-Al-Co-LDH nanosheets make it an efficient photocatalyst for the removal of anionic pollutants from water under simulated sunlight irradiation. The degradation efficiency of Congo red (CR) with Zn-Al-Co-LDH@CN catalyst was 92.7%. Regarding the effect of scavengers on the dye, ethylenediaminetetraacetic acid had a higher value than ethanol and benzoquinone (BQ) implying the considerable role of the hole (h+) in decomposing CR compared to the insignificant role of OH center dot and O2 center dot. During five sequential runs, a decline of less than 10% was observed in the removal efficiency of CR. The removal efficiency of chemical oxygen demand and total organic carbon was approximately 71% and 52%, respectively, within 400 min confirming the mineralization of CR.