Synthesis of 3D Sb2O3-based heterojunction reinforced by SPR effect and photo-Fenton mechanism for upgraded oxidation of metronidazole in water environments.

The traditional homogenous and heterogenous Fenton reactions have frequently been restrained by the lower production of Fe2+ ions, which significantly obstructs the generation of hydroxyl radicals from the decomposition of H2O2. Thus, we introduce novel photo-Fenton-assisted plasmonic heterojunctions by immobilizing Fe3O4 and Bi nanoparticles onto 3D Sb2O3 via co-precipitation and solvothermal approaches. The ternary Sb2O3/Fe3O4/Bi composites offered boosted photo-Fenton behavior with a metronidazole (MNZ) oxidation efficiency of 92% within 60 min. Among all composites, the Sb2O3/Fe3O4/Bi-5% hybrid exhibited an optimum photo-Fenton MNZ reaction constant of 0.03682 min- 1, which is 5.03 and 2.39 times higher than pure Sb2O3 and Sb2O3/Fe3O4, respectively. The upgraded oxidation activity was connected to the complementary outcomes between the photo-Fenton behavior of Sb2O3/Fe3O4 and the plasmonic effect of Bi NPs. The regular assembly of Fe3O4 and Bi NPs enhances the surface area and stability of Sb2O3/Fe3O4/Bi. Moreover, the limited absorption spectra of Sb2O3 were extended into solar radiation by the Fe3+ defect of Fe3O4 NPs and the surface plasmon resonance (SPR) effect of Bi NPs. The photo-Fenton mechanism suggests that the co-existence of Fe3O4/Bi NPs acts as electron acceptor/donor, respectively, which reduces recombination losses, prolongs the lifetime of photocarriers, and produces more reactive species, stimulating the overall photo-Fenton reactions. On the other hand, the photo-Fenton activity of MNZ antibiotics was optimized under different experimental conditions, including catalyst loading, solution pH, initial MNZ concentrations, anions, and real water environments. Besides, the trapping outcomes verified the vital participation of •OH, h+, and •O2- in the MNZ destruction over Sb2O3/Fe3O4/Bi-5%. In summary, this work excites novel perspectives in developing boosted photosystems through integrating the photocatalysis power with both Fenton reactions and the SPR effects of plasmonic materials.

Decoration of 0D Bi3NbO7 nanoparticles onto 2D BiOIO3 nanosheets as visible-light responsive S-scheme photocatalyst for photo-oxidation of antibiotics in wastewater.

In this work, a new S-type hybrid composed of 2D BiOIO3 and 0D Bi3NbO7 was proposed and hybridized by a facile self-assembly strategy. The developed nanomaterials were characterized and identified by a series of sophisticated analyses, like XRD, SEM, EIS, XPS, PL, UPS, EDS, BET, M-S, TEM, HRTEM, and DRS. The photocatalytic behavior of BiOIO3/Bi3NbO7 was examined and optimized against amoxicillin (AMX) and other types of antibiotics under a variety of environmental conditions, such as visible light (150 W LED), direct sunlight, pH (3-11), catalyst dosages (20-80 mg), humic acid (0-24 mg/L), AMX concentration (10-40 mg/L), and different inorganic ions (0.05 M). The optimized BiOIO3/Bi3NbO7 hybrid attained exceptional AMX degradation activity (96.5%) under visible light (60 min), with a reaction constant of up to 0.04559 min-1, exceeding bare BiOIO3 and Bi3NbO7 by 5.57 and 5.3 folds, respectively. The obtained BiOIO3/Bi3NbO7 hybrid unclosed expanded light utilization behavior compared with neat catalysts, which originates from the powerful incorporation between BiOIO3 and Bi3NbO7 in the S-type system. The radical investigations confirmed the superiority of BiOIO3/Bi3NbO7 in generating both •OH and •O2- during the photoreaction. The novel Bi3NbO7-based heterojunction afforded robust photostability in five treatment cycles and simple charge transfer activity in the S-type route, boosting the photo-mechanism for antibiotic degradation in an efficient manner. The building of the S-scheme heterojunction between BiOIO3 and Bi3NbO7 stimulates the utilization of holes by the recombination process and promotes the overall stability of the composite. Our study introduces a new class of semiconductor heterojunctions that may contribute to the development potential of the photocatalysis sector in wastewater treatment.

Reasonable decoration of CuO/Cd0.5Zn0.5S nanoparticles onto flower-like Bi5O7I as boosted step-scheme photocatalyst for reinforced photodecomposition of bisphenol A and Cr(VI) reduction in wastewater.

Building S-scheme heterostructures is a sophisticated approach to receiving outstanding catalysts for environmental detoxification. Herein, ternary CuO/Cd0.5Zn0.5S/Bi5O7I (CO/CZS/BOI) nanocomposites were constructed by in-situ decorating of CuO and Cd0.5Zn0.5S nanoparticles onto Bi5O7I micro-sphere in a facile route. The optimal CO/CZS/BOI reflected reinforced bisphenol A (BPA) photo-oxidation (95% in 70 min) and Cr(VI) photo-reduction (96.6 in 60 min) under visible light. Besides, CO/CZS/BOI afforded 5.10 (4.44), 4.42 (3.71), and 6.60 (5.27) fold reinforcement in the BPA (Cr(VI)) photo-reaction rate compared to BOI, CZS, and CO, respectively. This behavior was linked to the development of S-scheme mechanisms resulting from the co-effects of BOI, CZS, and CO in retaining the optimum redox capacity, facilitating the dissolution of photo-carriers, increasing reactive sites, and strengthening the visible-light response. The parameters influencing the catalytic reaction of CO/CZS/BOI, such as light intensity, catalyst dosage, and pH, were deeply studied. The quenching tests declared the prominent roles •O2- and •OH in the breaking down of BPA and the participation of electrons and •O2- in the photocatalytic conversion of Cr(VI). The cyclic tests verified the robust photostability of CO/CZS/BOI, which is associated with the reintegration process between the free h+ coming from CZS and the photo-induced e- of CO and BOI in the S-scheme system. In conclusion, the present study provides a profound understanding of the photo-reaction mechanism of CO/CZS/BOI and introduces a novel concept for constructing a superior dual-Scheme system for efficient wastewater detoxification.

Design and construction of a robust ternary Bi5O7I/Cd0.5Zn0.5S/CuO photocatalytic system for boosted photodegradation of antibiotics via dual-S-scheme mechanisms: Environmental factors and degradation intermediates.

The detection of efficacious and environment-friendly nanomaterials with prominent photocatalytic performance is crucial for the detoxification of antibiotics in wastewater. Herein, a dual-S-scheme Bi5O7I/Cd0.5Zn0.5S/CuO semiconductor was designed and fabricated via a simple approach to degrade tetracycline (TC) and other types of antibiotics under LED illumination. However, Cd0.5Zn0.5S and CuO nanoparticles were decorated on the surface of the Bi5O7I microsphere to create a dual-S-scheme system that stimulates visible-light utilization and facilitates the dissolution of excited photo-curriers. Therefore, the Bi5O7I/Cd0.5Zn0.5S/CuO system offers strong redox ability, which reflects reinforced photocatalytic activity and robust stability. The ternary heterojunction discloses enhanced TC detoxification efficiency of 92% in 60 min with TC destruction rate constant of 0.04034 min-1, outperforming pure Bi5O7I, Cd0.5Zn0.5S, and CuO by 4.27, 3.20, and 4.80 folds, respectively. Besides, Bi5O7I/Cd0.5Zn0.5S/CuO manifests outstanding photo-activity against a series of antibiotics like norfloxacin, enrofloxacin, ciprofloxacin, and levofloxacin under the same operational conditions. The active species detection, TC destruction pathways, catalyst stability, and photoreaction mechanisms of Bi5O7I/Cd0.5Zn0.5S/CuO were accurately explained in detail. Summarily, this work introduces a new class of dual-S-scheme system with strengthened catalytic properties to effectively eliminate the antibiotics in wastewater under visible-light illumination.

Catalytic-oxidative/adsorptive denitrogenation of model hydrocarbon fuels under ultrasonic field using magnetic reduced graphene oxide-based phosphomolybdic acid (PMo-Fe3O4/rGO).

In this work, the effect of ultrasound irradiation on the catalytic oxidative/adsorptive denitrogenation (COADN) of model hydrocarbon fuels (composed of pyrroleor indoleas an organonitrogen compounds dissolved in n-nonane) has been investigated using magnetic reduced graphene oxide supported with phosphomolybdic acid (PMo-Fe3O4/rGO) as a heterogeneous catalyst/adsorbent and hydrogen peroxide as an oxidant. The synthesized PMo-Fe3O4/rGO nanocomposite was characterized by XRD, FE-SEM, VSM and BET surface area analysis methods. Moreover, different experimental variables including catalyst dose, initial pyrrole/indoleconcentration, H2O2 to pyrrole/indole molar ratio, ultrasound power and sonication time have been studied on the COADN process. The regeneration/recyclability of PMo-Fe3O4/rGO catalyst was also examined. Experimental results revealed that, the ultrasound treatment significantly improved the adsorption process of organonitrogen compounds from model fuels (qe increased by 50.3% for pyrrole and 18% for indole). Furthermore, high ultrasound-aided catalytic oxidative denitrogenation efficiency (85.6% for pyrrole and 90% for indole) has been attained under optimal conditions (ultrasonic power = 200 W, sonication time = 240 min, catalyst dose = 2 g/L, and H2O2:pyrrole/indole molar ratio = 5). The recyclability of catalyst displayed that the prepared catalyst can be reused five times without any significant reduction in its performance.