A series of MgAl layer double hydroxide-based materials intercalated with Clitoria ternatea flower extract as photocatalysts in the ciprofloxacin degradation

Abstract

The preparation of MgAl Layer Double Hydroxide (LDH) was performed using the coprecipitation method. Pristine MgAl LDH was calcined at 500 °C to produce the MgAl Layer Double Oxide (LDO). The two materials were modified via restacking-delaminating the bioactive compounds from the flower extract of Clitoria ternatea (CT) to produce MgAl LDHCT and MgAl LDOCT. Modifications are performed to enhance the stability of the catalyst structure, allowing its higher photocatalytic activities and regeneration use. The prepared catalysts were characterized using XRD, FT-IR, UV-DRS, BET, and SEM-EDX. The XRD diffraction pattern showed that the three catalysts have typical diffraction patterns commonly observed in LDH-based materials. FT-IR spectra confirmed that MgAl LDHCT and MgAl LDOCT showed combined spectra of its precursor materials. MgAl LDOCT has the lowest bandgap energy with the highest degradation kinetics. BET and SEM-EDX characterization shows uniform surface and pore size on MgAl LDOCT. The prepared catalysts were used in the ciprofloxacin photodegradation under UV light. The optimal catalyst dose was 5 mg, while the optimal pH was 5. MgAl LDOCT, MgAl LDHCT, and MgAl LDH showed ciprofloxacin degradation capacity up to 73.300%, 65.739%, and 71.320%, respectively, within 120 min. Repeated use of the catalyst up to the third cycle resulted in%R reaching 80.871%, 74.003%, and 52.025%, respectively, by MgAl LDHCT, MgAl LDOCT, and MgAl LDH. Compared to pristine MgAl LDH, the CT intercalated catalysts exhibited more excellent stability.