CuO-NiO-Embedded Guar Gum Hydrogel as an Efficient Catalyst for Dyes Removal.

In this work, Guar gum and copper oxide-nickel oxide (GG-CuO-NiO) hydrogel were produced with the help of formaldehyde solution to display an efficient catalytic performance toward the catalytic degradation of selected dyes (Methylene Blue (MB), Methyl Orange (MO), and Eosin Yellow (EY)) in the presence of NaBH₄. The morphological and structural properties of the prepared hydrogel were thoroughly analyzed using SEM, EDX, XRD, and FT-IR techniques. According to the results, the GG-CuO-NiO hydrogel was able to reduce MB by 95% in one minute, 90.0% in four minutes, and 80.0% in 10 min for MO and EY, respectively. The catalytic efficiency of the hydrogel for MB was studied by adjusting its concentrations, varying reducing agent concentrations, and altering the amount of gel used. Using the recyclability method, which involved testing the GG-CuO-NiO hydrogel multiple times for the reduction of MB, the stability, reusability, and loss of catalytic activity of the hydrogel were examined. As a result, the designed GG-CuO-NiO hydrogel was stable for up to four times toward the reduction of MB. Lastly, the efficiency of the GG-CuO-NiO hydrogel was evaluated for MB removal in real samples and displayed exceptional reduction capabilities.