Reduced graphene oxide/ZnFe2O4 nanocomposite as an efficient catalyst for the photocatalytic degradation of methylene blue dye

Electrocatalytic Degradation of Rhodamine B on the Sb-Doped SnO2/Ti Electrode in Alkaline Medium

To realize efficient electrocatalytic degradation of organic compounds in alkaline wastewater, an Sb-doped SnO2/Ti electrode was fabricated and employed for the removal of Rhodamine B (RhB), and the electrocatalytic oxidation performance of this electrode was assessed in an alkaline medium. In an alkaline solution (pH 11), the complete fading of 50 mg·L-1 RhB could be achieved after 150 min of degradation, the removal efficiency of the chemical oxygen demand reached 56.1% at 300 min, and the degradation process of RhB followed the pseudo-first-order kinetic model very well. Under the attack of hydroxyl radicals, partial RhB was degraded to low-molecular-weight organic acids through N-demethylation and the destruction of the conjugated chromophore. Various techniques including scanning electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and cycle voltammetry were used to examine the changes in the morphology and structure, as well as the activity of the Sb-doped SnO2/Ti electrode before and after use. The Sb-doped SnO2/Ti electrode could be reproduced in batches, and each electrode was reused up to eight times without a significant decrease in degradation ability; the leaching amount of antimony was significantly lower than the national emission standard. The electrocatalytic oxidation of the dye wastewater sample was also performed with the desired results, indicating that electrochemical oxidation is a very promising technology for the treatment of alkaline dye wastewater using a Sb-doped SnO2/Ti electrode.

Fabrication of hybrid covalent triazine framework-zinc ferrite spinel to uplift visible light-driven photocatalytic organic pollutant degradation

The tunability of porous covalent triazine frameworks (CTFs) can mitigate poor photostability and rapid hole-electron recombination. Herein, an excellent improvement of visible light-driven photocatalytic pollutant degradation was achieved using a hybrid semiconductor of covalent triazine framework-zinc ferrite spinel catalysts (CTF-ZnFe₂O₄). The as-prepared CTF-ZnFe₂O₄ composites were fabricated using a facile one-pot ionothermal method. The hybrid photocatalysts were identified using X-ray diffraction (XRD), scanning electron microscopy/energy-dispersive X-ray (SEM-EDX), X-ray photoelectron spectrometer (XPS), Brunauer-Emmett-Teller (BET), Fourier transform infrared (FTIR), and UV-visible diffuse reflection spectroscopy (UV-vis DRS) characterizations. The analysis reveals that hybridization successfully ensued and altered the crystallinity structure, morphology, surface area, and bandgap energy of hybrid material. It was found that CTF-ZnFe₂O₄ 90:10 is very effective for the degradation of MB in a UV-vis light photocatalytic process with the efficiency of 95.4% and k_obs of 0.421 min^-1 for degradation of 50 mg/L MB with 0.5 g/L dosages for 120 min. Additionally, the scavenger study, effect of additional oxidants, and stability were performed for the practical application of a hybrid photocatalyst. CTF-ZnFe₂O₄ 90:10 shows outstanding pollutant degradation in sunlight irradiation and high stability with only a 5.2% reduction after a five-times sequential recycling process. Moreover, the photocatalytic mechanism of as-prepared CTF-ZnFe₂O₄ was mainly influenced by [Formula: see text] radical compared to [Formula: see text] and [Formula: see text] radicals. Overall, The as-prepared CTF-ZnFe₂O₄ shows significant potential to be utilized for photocatalytic wastewater treatment.

Starch-Stabilized Iron Oxide Nanoparticles for the Photocatalytic Degradation of Methylene Blue

The photocatalytic Fenton process, which produces a strong oxidant in the form of hydroxyl radicals, is a useful method to degrade organic contaminants in water. The Fenton reaction uses hydrogen peroxide and Fe2+ ions under relatively acidic conditions (typically pH 2–3) to maintain solubility of the iron catalyst but is troublesome due to the large volumes of decontaminated yet highly acidic water generated. Starch-stabilized iron (Fe2+/Fe3+) oxide nanoparticles were synthesized to serve as a colloidal catalyst system as the hydrophilic starch effectively prevents precipitation of the nanoparticles under conditions closer to neutrality. To evaluate the usefulness of this catalyst system for the photo-Fenton degradation of methylene blue as a model dye, the preparation protocol used and the iron loading in the starch were varied. The photocatalytic Fenton reaction was investigated at pH values up to 4. Not only were the starch-stabilized catalysts able to decolorize the dye but also to mineralize it in part, that is, to degrade it to carbon dioxide and water. The catalysts could be reused in several degradation cycles. This demonstrates that starch is an efficient stabilizer for iron oxide nanoparticles in aqueous media, enabling their use as environmentally friendly and cost-effective photo-Fenton catalysts. These starch-stabilized iron nanoparticles may also be useful to degrade other dyes and pollutants in water, such as pesticides.

Effect of covalent organic framework modified graphene oxide on anticorrosion and self-healing properties of epoxy resin coatings

Graphene oxide (GO) can enhance the corrosion resistance of epoxy coating, but there are problems such as poor filler dispersion and mechanical damage that will reduce the coating corrosion resistance. To resolve these problems, here, we used a facile and green liquid-phase synthetic strategy to grow covalent organic framework (COF) on GO sheets with 1,3,5-Triformylphloroglucinol and p-phenylenediamine as monomers for the COF synthesis. The COF could not only improve the compatibility of GO with epoxy coating, but also act as a nanocontainer for loading corrosion inhibitors. Electrochemical impedance spectroscopy showed that the low-frequency impedance of GO/COF-2% coating immersed in 3.5 wt% NaCl solution for 60 days was 8.58 × 10⁸ Ω cm². This was one order of magnitude higher than that of GO-2%, showing excellent corrosion resistance. Then, corrosion inhibitor of benzotriazole (BTA) was loaded into GO/COF, where the adsorption and release of BTA was controlled by environmental pH values. Results proved that the GO/COF@BTA-2% reinforced epoxy coating had superior corrosion resistance as well as self-healing ability because of the good compatibility, greater crosslinking density and controllable release of BTA.

Catalytic and Medical Potential of a Phyto-Functionalized Reduced Graphene Oxide-Gold Nanocomposite Using Willow-Leaved Knotgrass

In the current study, a simple, environmentally friendly, and cost-effective reduced graphene oxide-gold nanoparticle (rGO-AuNP) nanocomposite was successfully phytosynthesized using the aqueous leaf extract of a common weed found on the Nile banks, Persicaria salicifolia, for the first time. The phytosynthesis of rGO-AuNPs was first confirmed via the color transformation from brown to black as well as throughvarious techniques such as transmission electron microscopy (TEM) and Raman spectroscopy. Two UV-vis peaks at 275 and 530 nm were observed for the nanocomposite with a typical particle size of mostly spherical AuNPs of 15-20 nm. However, other shapes were occasionally detected including rods, triangles, and rhomboids. Existing phytoconstituents such as flavonoids and glycosides in the plant extract were suggested to be responsible for the phytosynthesis of rGO-AuNPs. The excellent catalytic efficacy of rGO-AuNPs against MB degradation was confirmed, and a high antibacterial efficiency against Escherichia coli and Klebsiella pneumonia was also confirmed. Promising antioxidant performance of rGO-AuNPs was also proved. Furthermore, it was concluded that rGO-AuNPs acquired higher efficiency than AuNPs synthesized from the same plant extract in all of the studied applications.

Mixed metal ferrite (Mn0.6Zn0.4Fe2O4) intercalated g-C3N4nanocomposite: efficient sunlight driven photocatalyst for methylene blue degradation

Visible active mixed metal ferrite intercalated semiconductor photocatalyst Mn_0.6Zn_0.4Fe₂O₄/g-C₃N₄was prepared via facile hydrothermal and liquid assembly method for methylene blue (MB) dye degradation. The prepared samples were well characterized in term of their functional groups, crystallinity, elemental analysis, surface morphology using Fourier transform infrared spectroscopy, x-ray diffraction spectroscopy, energy dispersive x-ray, and scanning electron microscopy, respectively. The optical response of catalysts was checked by estimating the energy band gap (E_g) of semiconductor photocatalysts using UV-vis spectroscopy. The photoluminescence spectroscopy was also performed to estimate the reduction in emission intensity after insertion of g-C₃N₄into Mn_0.6Zn_0.4Fe₂O_4.The novel composition of Mn_0.6Zn_0.4Fe₂O₄with g-C₃N_4,improved the optical response of pristine photocatalysts due to the reduction in the energy band gap and insertion of heterojunction. The surface area analysis of Mn_0.6Zn_0.4Fe₂O₄and Mn_0.6Zn_0.4Fe₂O₄/g-C₃N₄were acquired by Brunauer-Emmett-Teller. Point zero charge was also determined to observe the surface behavior of composite under different solution pH. Various parameters such as pH, catalyst dose, oxidant dose, irradiation time and initial dye concentration were optimized, and their effects were studied in photo-Fenton process. It was observed that 98% MB dye was degraded under optimized conditions (pH = 8, composite dose = 50 mg/100 ml, oxidant dose = 7 mM, initial dye conc. = 10 ppm, and irradiation time = 120 min). The results showed that when the ferrites of mixed metals (Mn, Zn) were used with g-C₃N₄their photocatalytic activity enhanced due to mutual effect of both mixed metals ferrite and g-C₃N₄, which is considerably higher than their individual effect already reported. Furthermore, the combined effect of independent variables was evaluated by response surface methodology.

Modified cobalt-manganese oxide-coated carbon felt anodes: an available method to improve the performance of microbial fuel cells

The novel MnCo₂O₄ (MCO/CF), CNTs-MnCo₂O₄ (CNTs-MCO/CF) and MnFe₂O₄-MnCo₂O₄ (MFO-MCO/CF) electrodes were prepared on carbon felt (CF) by simple hydrothermal and coating method as anodes for MFC. The modified anodes combine the electrocatalytic properties of transition metal oxides (TMOs), the high electrical conductivity of CNTs and the good biocompatibility of CF. These anodes play a synergistically role in the synthesis of structural, to realize high-efficiency electron transfer, low resistance and sufficient space for microbial colonization, while also ensuring high power density. The maximum power density of the composite electrodes CNTs-MCO/CF and MFO-MCO/CF were 4268 mW/m³ and 3660 mW/m³, respectively. The synergistic effect of multi-component effectively improves the performance of MFC. This work not only offers a good design and preparation concept for functional TMOs composite electrodes, but also provides an important guide for the fabrication of CNTs-doped MFC anodes.

Tuning Electrocatalytic Aptitude by Incorporating α-MnO2 Nanorods in Cu-MOF/rGO/CuO Hybrids: Electrochemical Sensing of Resorcinol for Practical Applications

In this study, Cu-MOF/rGO/CuO/α-MnO₂ nanocomposites have been fabricated by a one-step hydrothermal method and used in the voltammetric detection of resorcinol (RS). The poor conductivity of MOFs in the field of electrochemical sensing is still a major challenge. A series of Cu-MOF/rGO/CuO/α-MnO₂ nanocomposites have been synthesized with varying fractions of rGO and with a fixed amount of α-MnO₂ via a facile method. These nanocomposites are well characterized using some sophisticated characterization techniques. The as-prepared nanohybrids have strongly promoted the redox reactions at the electrode surface due to their synergistic effects of improved conductivity, high electrocatalytic activity, an enlarged specific surface area, and a plethora of nanoscale level interfacial collaborations. The electrode modified with Cu-MOF/rGO/CuO/α-MnO₂ has revealed superior electrochemical properties demonstrating linear differential pulse voltammetry (DPV) responses from a 0.2 to 22 μM RS concentration range (R² = 0.999). The overall results of this sensing podium have shown excellent stability, good recovery, and a low detection limit of 0.2 μM. With excellent sensing performance achieved, the practicability of the sensor has been evaluated to detect RS in commercial hair color samples as well as in tap water and river water samples. Therefore, we envision that our hybrid nanostructures synthesized by the structural integration strategy will open new horizons in material synthesis and biosensing platforms.

Rare earth metal (Sm) doped zinc ferrite (ZnFe2O4) for improved photocatalytic elimination of toxic dye from aquatic system

Wastewater remediation is the serious topic that must be taken into concern which would be a most crucial problem that destroys the natural properties as well as it has some worse effect on living organisms. By doing better wastewater management, the scarcity of water for domestic purposes can be eventually managed. Dyes are main organic pollutant that must be removed from wastewater. Pristine, 1% Sm doped and 2% Sm doped ZnFe₂O₄ were prepared through simple co-precipitation method. The materials were further analyzed for its structure, optical properties, rotational properties and morphology studies. These analyses were investigated with respect to X-ray diffraction, UV-vis spectroscopy, photoluminescence and scanning electron microscopic studies. XRD pattern of Pristine, 1% Sm doped and 2% Sm doped ZnFe₂O₄ was matched with JCPDS Card #89-1012 with cubic phase. Bandgap energy of prepared samples were 1.7 eV, 1.65 eV and 1.47 eV. The prepared cationic dye was degraded with help of visible light irradiation. 2% Sm doped ZnFe₂O₄ nanoparticles easily removed 65% of dye within 1 h duration. 2% Sm doped ZnFe₂O₄ was tested for its reusability and efficiency was stable for more than three cycles. This shows the stability of the sample towards degrading the cationic dye. By the doping of Samarium, ZnFe₂O₄ nanoparticles enthusiastically removed cationic dye and it proves to be an efficient candidate in removing dyes and can help in wastewater treatment in upcoming era.

Nickel ferrite/MXene-coated carbon felt anodes for enhanced microbial fuel cell performance

In recent years, the modification of electrode materials for enhancing the power generation of microbial fuel cells (MFCs) has attracted considerable attention. In this study, a conventional carbon felt (CF) electrode was modified by NiFe₂O₄ (NiFe₂O₄@CF), MXene (MXene@CF), and NiFe₂O₄-MXene (NiFe₂O₄-MXene@CF) using facile dip-and-dry and hydrothermal methods. In these modified CF electrodes, the electrochemical performance considerably improved, while the highest power density (1385 mW/m²), which was 5.6, 2.8, and 1.4 times higher than those of CF, NiFe₂O₄@CF, and MXene@CF anodes, respectively, was achieved using NiFe₂O₄-MXene@CF. Furthermore, electrochemical impedance spectroscopy and cyclic voltammetry results confirmed the superior bioelectrochemical activity of a NiFe₂O₄-MXene@CF anode in a MFC. The improved performance could be attributed to the low charge transfer resistance, high conductivity and number of catalytically active sites of the NiFe₂O₄-MXene@CF anode. Microbial community analysis demonstrated the relative abundance of electroactive bacteria on a NiFe₂O₄-MXene@CF anodic biofilm rather than CF, MXene@CF, and NiFe₂O₄@CF anodes. Therefore, these results suggest that combining the favorable properties of composite materials such as NiFe₂O₄-MXene@CF anodes can open up new directions for fabricating novel electrodes for renewable energy-related applications.

Novel Structures and Applications of Graphene-Based Semiconductor Photocatalysts: Faceted Particles, Photonic Crystals, Antimicrobial and Magnetic Properties

Graphene, graphene oxide, reduced graphene oxide and their composites with various compounds/materials have high potential for substantial impact as cheap photocatalysts, which is essential to meet the demands of global activity, offering the advantage of utilizing “green” solar energy. Accordingly, graphene-based materials might help to reduce reliance on fossil fuel supplies and facile remediation routes to achieve clean environment and pure water. This review presents recent developments of graphene-based semiconductor photocatalysts, including novel composites with faceted particles, photonic crystals, and nanotubes/nanowires, where the enhancement of activity mechanism is associated with a synergistic effect resulting from the presence of graphene structure. Moreover, antimicrobial potential (highly needed these days), and facile recovery/reuse of photocatalysts by magnetic field have been addresses as very important issue for future commercialization. It is believed that graphene materials should be available soon in the market, especially because of constantly decreasing prices of graphene, vis response, excellent charge transfer ability, and thus high and broad photocatalytic activity against both organic pollutants and microorganisms.

A study on the interaction of nile blue with Uracils: A spectroscopic and computational approach

The present work focuses the investigation on fluorescence quenching of nile blue (NB) in presence of various substituted uracil molecules. UV-Visible absorption studies signify the possibility of ground state complex formation between NB and uracil molecules. The increase in concentration of quencher molecules greatly influences the emission spectra of NB. The bimolecular quenching rate constant (k_q) were calculated and found to depend on the position and electronic properties of substituent in quencher molecules. Fluorescence quenching experiments were performed at different temperature to calculate the thermodynamic parameters. The fluorescence lifetime measurements show that the quenching process proceeds through static quenching. The mechanism of fluorescence quenching includes the possibility of proton transfer. The bond dissociation enthalpy (BDE) reveals the release of H from the quencher molecules. The quencher molecules possess antioxidant activity and identified using deoxyribose degradation assay. The position of substituent and its electronic property are key features to address the antioxidant activity of uracil molecules.

MnCo2O4 coated carbon felt anode for enhanced microbial fuel cell performance

A highly efficient anode is very crucial for an improved microbial fuel cell (MFC) performance. In this study, a binder-free manganese cobalt oxide (MnCo₂O₄@CF) anode was synthesized using a conventional carbon felt (CF) by a facile hydrothermal method. A large electrochemically active and rough electrode surface area of MnCo₂O₄@CF anode improved the substrate fluxes and microbial adhesion/growth. Furthermore, the electrochemical tests on the synthesized anode confirmed the superior bioelectrochemical activity, reduced ion transfer resistance, and excellent capacitance. This resulted in an improved power density (945 mW/m²), which was 3.8 times higher than that of CF anode. The variable valence state, high stability and biocompatibility of MnCo₂O₄@CF resulted in continuous current density performance for five MFC cycles. High-throughput biofilm analysis revealed the enrichment of electricity producing phylum of Proteobacteria and Bacteroidetes (∼90.0%), which signified that the modified MnCo₂O₄ anode accelerated the enrichment of electro-active microbes.

Synthesis and Structural Studies of Manganese Ferrite and Zinc Ferrite Nanocomposites and Their Use as Photoadsorbents for Indigo Carmine and Methylene Blue Dyes

Solar-moderated adsorptions of indigo carmine and methylene blue dyes were investigated using manganese and zinc ferrite capped with biochar prepared from the root of Chromolaena odorata. TEM micrograph of the as-prepared manganese ferrite nanocomposites (MnFe₂O₄@BC) revealed octagonally shaped particles with an average size of 42.64 nm while the zinc ferrite nanocomposite (ZnFe₂O₄@BC) micrograph revealed mixtures of rod- and cone-shaped particles with an average size of 43.82 nm. Biochar capping of MnFe₂O₄@BC reduced the band gap from 3.63 to 2.08 eV. The nanocomposite surface areas were 197.64 and 92.14 m²/g for MnFe₂O₄@BC and ZnFe₂O₄@BC, respectively. Photoadsorption of the as-prepared nanocomposites showed that 10 mg of ZnFe₂O₄@BC effectively removed 69.07 and 98.60% of 70 mg/L indigo carmine and methylene blue dyes while MnFe₂O₄@BC removed 77.65 and 94.83% of indigo carmine and methylene blue dyes after 2 h of equilibration under visible light irradiation, respectively. The nonlinear form of the Langmuir isotherm had a better approximation to the experimental solid-phase concentration (q _e) for the adsorption of indigo carmine dye using both nanocomposites. In contrast, the linear form gave a better goodness-of-fit for the adsorptions of methylene blue dye. The manganese ferrite (MnFe₂O₄@BC) and zinc ferrite (ZnFe₂O₄@BC) nanocomposites showed no inhibition of Escherichia coli and Staphylococcus aureus, which indicates that they could be used for both biological and environmental applications.

An Overview on Graphene-Metal Oxide Semiconductor Nanocomposite: A Promising Platform for Visible Light Photocatalytic Activity for the Treatment of Various Pollutants in Aqueous Medium

Graphene is one of the most favorite materials for materials science research owing to its distinctive chemical and physical properties, such as superior conductivity, extremely larger specific surface area, and good mechanical/chemical stability with the flexible monolayer structure. Graphene is considered as a supreme matrix and electron arbitrator of semiconductor nanoparticles for environmental pollution remediation. The present review looks at the recent progress on the graphene-based metal oxide and ternary composites for photocatalysis application, especially for the application of the environmental remediation. The challenges and perspectives of emerging graphene-based metal oxide nanocomposites for photocatalysis are also discussed.

Efficiency improvement in non-enzymatic H2O2 detection induced by the simultaneous synthesis of Au and Ag nanoparticles in an RGO/Au/Fe3O4/Ag nanocomposite

Developing a quick and precise technique for hydrogen peroxide (H₂O₂) detection would open up a new class of technologies for biological, medical and chemical applications.

Construction of ZnFe2O4/rGO composites as selective magnetically recyclable photocatalysts under visible light irradiation

This paper reports on highly active ZnFe₂O₄/reduced graphene oxide (ZnFe₂O₄/rGO) nanocomposites synthesized by a modified sol-gel method. The as-prepared samples have been characterized by XRD, TEM, XPS and other detection methods, which demonstrate that ZnFe₂O₄ nanoparticles (NPs) with a diameter of 15 ∼ 50 nm were densely grown on the rGO substrates. The photocatalytic activities of ZnFe₂O₄/rGO catalysts were evaluated by the degradation of Methylene blue (MB) under visible light. The results showed that the ZnFe₂O₄/rGO catalysts had high photocatalytic activity, and the degradation efficiency of MB was almost 100% within 180 min. Moreover, the ZnFe₂O₄/rGO catalysts also had a great removal effect on Rhodamine B (RhB) and Methyl orange (MO). Mechanistic studies revealed that the rGO acted as a stabilizer to prevent ZnFe₂O₄ from aggregation and improved the separation of photo-generated electrons. The high efficiency for dye degradation was attributed to the generation of hydroxyl radicals (·OH) via the photochemical decomposition of H₂O₂ on ZnFe₂O₄/rGO catalysts, which was responsible for the oxidation of the dyes. Of note, the ZnFe₂O₄/rGO catalyst maintained an efficiency of over 90% after five cycles. The XRD, XPS and VSM characterization revealed that the ZnFe₂O₄/rGO catalysts had a stable crystal structure and can be easily separated.

Potential utility of graphene-based nano spinel ferrites as adsorbent and photocatalyst for removing organic/inorganic contaminants from aqueous solutions: A mini review

Toxic substances such as heavy metals or persistent organic pollutants raise global environmental concerns. Thus, diverse water decontamination approaches using nano-adsorbents and/or photocatalysts based on nanotechnology are being developed. Particularly, many studies have examined the removal of organic and inorganic contaminants with novel graphene-based nano spinel ferrites (GNSFs) as potential cost-effective alternatives to traditionally used materials, owing to their enhanced physical and chemical properties. The introduction of magnetic spinel ferrites into 2-D graphene-family nanomaterials to form GNSFs brings various benefits such as inhibited particle agglomeration, enhanced active surface area, and easier magnetic separation for reuse, making the GNSFs highly efficient and eco-friendly materials. Here, we present a short review on the state-of-the-art progresses on developments of GNSFs, as well as their potential application for removing several recalcitrant contaminants including organic dyes, antibiotics, and heavy metal ions. Particularly, the mechanisms involved in the adsorptive and photocatalytic degradation are thoroughly reviewed, and the reusability of the GNSFs is also highlighted. This review concludes that the GNSFs hold great potential in remediating contaminated aquatic environments. Further studies are needed for their practical and large-scale applications.

PEDOT/NiFe2O4 nanocomposites on biochar as a free-standing anode for high-performance and durable microbial fuel cells

The competitive and hopeful route is endowed to convert wastes into profitable products by generating green energy from wastewater using PEDOT/NiFe₂O₄ nanostructures on the biomass-derived electrode as anode in microbial fuel cells.

A non-enzymatic glucose sensor with enhanced anti-interference ability based on a MIL-53(NiFe) metal–organic framework

The MIL-53(NiFe) MOF was used as a molecular sieve to improve the anti-interference ability in glucose detection.

Photocatalytic degradation of bisphenol A over a ZnFe2O4/TiO2 nanocomposite under visible light

A ZnFe₂O₄-TiO₂ nanocomposite combining p-type ZnFe₂O₄ and n-type TiO₂ was successfully fabricated. The ZnFe₂O₄-TiO₂ nanocomposite greatly enhanced the bisphenol A (BPA) photodegradation under visible light irradiation at 465 ± 40 nm. Loading TiO₂ with 1 wt% of ZnFe₂O₄ produced high photocurrent and low charge transfer resistance. The photodegradation rate of BPA by ZnFe₂O₄-TiO₂, which was highly dependent on the water chemistry including pH, anions, and humic acid, was 20.8-21.4 times higher than that of commercial TiO₂ photocatalysts. Chloride and sulfate ions enhanced BPA photodegradation mostly due to the production of more radical species; whereas nitrate, dihydrogen phosphate, and bicarbonate ions decreased the photodegradation rate of BPA due to the scavenge of hydroxyl radicals. The photoactivity and recyclability of ZnFe₂O₄-TiO₂ in lake water was also assessed. A near complete BPA removal from lake water was observed under visible light irradiation. Furthermore, >90% of photocatalytic activity toward BPA degradation was achieved in 5 cycles of continuous addition of BPA to the lake water. The BPA degradation intermediates were identified by HPLC/MS/MS and possible reaction pathways were proposed. Results clearly demonstrate the excellent visible-light-sensitive photocatalytic degradation of BPA over ZnFe₂O₄-TiO₂ composite which has a great application potential for the decomposition of emerging contaminants in impaired waters.

Fe3O4/ZnFe2O4 micro/nanostructures and their heterogeneous efficient Fenton-like visible-light photocatalysis process

A Fenton-like visible-light photocatalyst composed of Fe₃O₄/ZnFe₂O₄ micro/nanostructures shows highly efficient photocatalysis in the degradation of R6G.