Green modification of NiAl LDH hinders photocatalytic efficiency in ciprofloxacin degradation under solar light irradiation

Pharmaceutical waste pollution, especially ciprofloxacin (CIP), has become a significant concern due to bacterial resistance and environmental impacts. Wastewater treatment using photodegradation with environmentally friendly catalysts is a viable option for achieving green chemistry. This study aims to modify NiAl Layered Double Hydroxide (LDH) and Layered Double Oxide (LDO) into heterojunction catalysts by adding natural extracts of butterfly pea flower ( Clitoria ternatea , CLE) and mangosteen rind ( Garcinia mangostana , GRE). NiAl LDH was modified through calcination and restacking methods. XRD and FT-IR results showed expected peaks of the initial material combination, confirming success. UV-DRS analysis indicated that the incorporation of CLE and GRE enhanced the material’s light responsiveness and reduced the bandgap energy, with GRE exhibiting more influence than CLE. Photocatalytic activity was studied through the CIP photolysis process and CIP degradation under both solar light and dark conditions, with optimization of catalyst mass, pH, and determination of kinetics. The NiAl LDO exhibited the best ability in CIP degradation, with an efficiency of 92.5 % and a kinetics of 0.024 min −1 over 90 min. Modification with natural extracts failed to improve catalytic performance. The GRE-modified catalyst, which contained numerous chromophore groups, surprisingly exhibited the lowest catalytic activity compared to the other catalysts. Further analyses through scavenger tests indicated that GRE accelerates electron recombination on the catalyst surface excessively, leading to a reduction in catalytic activity. The following studies may focus on evaluating the specific type and quantity of extract used to modify LDH-based materials.