Hierarchical porous TiO 2 with a uniform distribution of anchored gold nanoparticles for enhanced photocatalytic efficiency and accelerated charge separation for the degradation of antibiotics

• Published in: Environmental science and pollution research international Vol. 30; no. 7; p. 17951
• Main Authors: Alsaidi, Mariam, Azeez, Fadhel A, Al-Hajji, Latifa A, Ismail, Adel A
• Format: Journal Article
• Language: English
• Published: Germany 01-02-2023
• Subjects: Anti-Bacterial Agents; Gold - chemistry; Metal Nanoparticles - chemistry; Porosity; Water; Photodegradation; Pyrolytic; NH2-MIL-125(Ti); Antibiotics; Au NPs
• ISSN: 1614-7499

A novel approach to synthesize porous Au/TiO
nanocomposites has been achieved through a pyrolytic strategy by employing NH
-MIL-125(Ti) as a TiO
precursor, and photo-deposition of Au nanoparticles (NPs) onto porous nanocrystalline TiO
with varying Au contents (0.05-0.5%). TEM images of Au/TiO
nanocomposites showed that TiO
particles were spherical structures, highly dispersed, and homogeneous with diameters of 10-15 nm, and Au NPs (20-30 nm) were anchored onto porous TiO
matrices with a uniform distribution. The synthesized Au/TiO
nanocomposites were assessed through the degradation of two antibiotic models, metronidazole (MNZ), and trimethoprim (TMP), under visible light and compared with undoped TiO
and commercial TiO
(P-25). The synthesized Au/TiO
photocatalyst revealed enhanced photocatalytic performance in the mineralization (80%) and degradation (100%) of MNZ and TMP in both water matrices compared to undoped TiO
(60%, 76%) and commercial P-25 (48%, 65%). The obtained 0.1% Au/TiO
nanocomposite could complete the mineralization of TMP and MNZ with rate constant values (4.47 × 10
 min
and 5.23 × 10
 min
) owing to the large well-developed porosity and high surface area of TiO
and the small size of Au NPs with high dispersity, surface plasmon resonance, and stability. The recyclability of the 0.1% Au/TiO
nanocomposite exhibited high durability without the leaching or loss of photocatalytic performance after four cycles. Complete degradation was achieved within 100 min in the water matrix from real wastewater, indicating promising results for the degradation of pharmaceuticals in the different water matrices. The present work opens a new route to synthesize low-cost, effective, and high photocatalytic performance nanocomposites with a small Au content as a cocatalyst onto semiconductor materials.