High-Performance Photocatalytic Hydrogen Production and Degradation of Levofloxacin by Wide Spectrum-Responsive Ag/Fe₃O₄ Bridged SrTiO₃/g-C₃N₄ Plasmonic Nanojunctions: Joint Effect of Ag and Fe₃O₄

Abstract

Highly photoresponsive semiconductor photocatalysis for energy and environmental applications require judicious choice and optimization of semiconductor interfaces for wide spectral capabilities. This work aims at rational designing of highly active SrTiO 3 /g-C 3 N 4 junctions bridged with Ag/Fe 3 O 4 nanoparticles for utilizing Z-scheme transfer and surface plasmon resonance effect of Ag augmented by iron oxide. The SrTiO 3 /(Ag/Fe 3 O 4 )/g-C 3 N 4 (SFC) catalyst was employed for photocatalytic hydrogen production and photodegradation of levofloxacin (LFC; 20 mg/L) under UV, visible, near infra-red, and natural solar light exhibiting high performance. Under visible light (<780 nm), SFC-3 sample (30 wt % g-C 3 N 4 and 3% Ag/Fe 3 O 4 ) shows a H 2 evolution of 2008 μmol g −1 h −1 which is ∼14 times that of bare g-C 3 N 4 . In addition, 99.3% removal of LFC was degraded in 90 min under visible light with retention of activity under sun. The inherent topological properties, complete, higher charge separation, and reduced recombination allowed this catalyst for a high photocatalytic response which was proved by UVdiffuse reflectance spectroscopy, photoluminescence, electrochemical impedance spectroscopy, and photocurrent response measurements. Scavenging experiments and electron spin resonance analysis reveal that the mechanism shifts from a dual charge transfer in case of binary junction to essential Z-scheme with incorporation of Ag/Fe 3 O 4 . Both • O 2 − and • OH are main active radicals in visible light, whereas • O 2 − majorly participate under UV. The synergistic effect of SrTiO 3 , g-C 3 N 4 , and plasmon resonance of Ag/Fe 3 O 4 not only improves light response and reduce recombination but also enhances the redox-ability of charge carriers. A H 2 production mechanism and LFC degradation pathway (degradation, defluorination, and hydrolysis) has been predicted. This work paves a way for development of photocatalysts working in practical conditions for pollution and energy issues.

Nickel and sulfur codoped TiO2 nanoparticles for efficient visible light photocatalytic activity

“…The The E VB potentials of pure, Ni, Sand Ni-S/TiO 2 were estimated as 2.449, 2.379, 2.279, 2.171 eV respectively [59,60].…”

A review of synthesis and morphology of SrTiO 3 for energy and other applications

“…It was noticed that the TCs were able to degrade effectively under visible light and the light harvesting was improved. Then, in 2018, Kumar et al did an experiment in levofloxacin (LFC) degradation with Ag/Fe 3 O 4 bridged SrTiO 3 /g‐C 3 N 4 with superior performance; it was able to fully degrade in 90 minutes. LFC is a popular antibiotic that belongs to fluoroquinolone family that used in treating severe bacterial infections .…”

The Power of Ionic Liquids: Crystal Facet Engineering of SrTiO3Nanoparticles for Tailored Photocatalytic Applications

“…All diffraction peaks can be indexed to the cubic perovskite structure of SrTiO 3 (PDF 35–734). No impurities, most importantly no diffraction peaks originating form SrCO 3 , an impurity frequently encountered when synthesizing SrTiO 3 , [ 8 ] could be detected. Average Scherrer crystal domain sizes were calculated from the FWHM values of the (110) diffraction peak and are summarized in Table 1 .…”

“…[ 7 ] SrTiO 3 has also shown to be an effective catalyst for the decomposition of organics, for example, tetracyclines and other pharmaceuticals that are found to accumulate through waste water from municipalities. [ 8 ] It also can help to remove NO X . [ 9 ] SrTiO 3 has even been applied in CO 2 reduction.…”