Enhanced Photocatalytic Performance of Hierarchical ZnFe2O4/g-C3N4 Heterojunction Composite Microspheres

Harnessing solar power for enhanced photocatalytic degradation of coloured pollutants using novel Mg-doped-ZnFe2O4/S@g-C3N4 heterojunction: A facile hydrothermal synthesis approach

The ability of heterogeneous photocatalysis to effectively remove organic pollutants from wastewater has shown great promise as a tool for environmental remediation. Pure zinc ferrites (ZnFe2O4) and magnesium-doped zinc ferrites (Mg@ZnFe2O4) with variable percentages of Mg (0.5, 1, 3, 5, 7, and 9 mol%) were synthesized via hydrothermal route and their photocatalytic activity was checked against methylene blue (MB) taken as a model dye. FTIR, XPS, BET, PL, XRD, TEM, and UV-Vis spectroscopy were used for the identification and morphological characterization of the prepared nanoparticles (NPs) and nanocomposites (NCs). The 7% Mg@ZnFe2O4 NPs demonstrated excellent degradation against MB under sunlight. The 7% Mg@ZnFe2O4 NPs were integrated with diverse contents (10, 50, 30, and 70 wt.%) of S@g-C3N4 to develop NCs with better activity. When the NCs were tested to degrade MB dye, it was revealed that the 7%Mg@ZnFe2O4/S@g-C3N4 NCs were more effective at utilizing solar energy than the other NPs and NCs. The synergistic effect of the interface formed between Mg@ZnFe2O4 and S@g-C3N4 was primarily responsible for the boosted photocatalytic capability of the NCs. The fabricated NCs may function as an effective new photocatalyst to remove organic dyes from wastewater.

Recent advances in spinel ferrite-based magnetic photocatalysts for efficient degradation of organic pollutants

Although spinel ferrite (MFe₂O₄, M = Zn, Ni, Mn, etc.) has been reported as a promising catalyst, its low photocatalytic activity under visible light greatly restricts its practical application. Spinel ferrite-based photocatalytic composites have exhibited improved efficiency for pollutant degradation, due to interface charge carrier mobility and structural modification. Meanwhile, due to its magnetism and stability, spinel ferrite composite can be easily recycled for long-term utilization, showing its high application potential. In this review, the recent advances in the construction and photocatalytic degradation of spinel ferrite composites are discussed, with an emphasis on the relationship between structural property and photocatalytic activity. In addition, to improve their photocatalytic application, the challenges, gaps and future research prospects are proposed.

Integration of Mn-ZnFe2O4 with S-g-C3N4 for Boosting Spatial Charge Generation and Separation as an Efficient Photocatalyst

The disposal of dyes and organic matter into water bodies has become a significant source of pollution, posing health risks to humans worldwide. With rising water demands and dwindling supplies, these harmful compounds must be isolated from wastewater and kept out of the aquatic environment. In the research presented here, hydrothermal synthesis of manganese-doped zinc ferrites’ (Mn-ZnFe₂O₄) nanoparticles (NPs) and their nanocomposites (NCs) with sulfur-doped graphitic carbon nitride (Mn-ZnFe₂O₄/S-g-C₃N₄) are described. The samples’ morphological, structural, and bonding features were investigated using SEM, XRD, and FTIR techniques. A two-phase photocatalytic degradation study of (0.5, 1, 3, 5, 7, 9, and 11 wt.%) Mn-doped ZnFe₂O₄ NPs and Mn-ZnFe₂O₄/(10, 30, 50, 60, and 70 wt.%) S-g-C₃N₄ NCs against MB was carried out to find the photocatalyst with maximum efficiency. The 9% Mn-ZnFe₂O₄ NPs and Mn-ZnFe₂O₄/50% S-g-C₃N₄ NCs exhibited the best photocatalyst efficiency in phase one and phased two, respectively. The enhanced photocatalytic activity of the Mn-ZnFe₂O₄/50% S-g-C₃N₄ NCs could be attributed to synergistic interactions at the Mn-ZnFe₂O₄/50% S-g-C₃N₄ NCs interface that resulted in a more effective transfer and separation of photo-induced charges. Therefore, it is efficient, affordable, and ecologically secure to modify ZnFe₂O₄ by doping with Mn and homogenizing with S-g-C₃N₄. As a result, our current research suggests that the synthetic ternary hybrid Mn-ZnFe₂O₄/50% S-g-C₃N₄ NCs may be an effective photocatalytic system for degrading organic pollutants from wastewater.

Construction of a Well-Defined S-Scheme Heterojunction Based on Bi-ZnFe2O4/S-g-C3N4 Nanocomposite Photocatalyst to Support Photocatalytic Pollutant Degradation Driven by Sunlight

Currently, organic dyes and other environmental contaminants are focal areas of research, with considerable interest in the production of stable, high-efficiency, and eco-friendly photocatalysts to eliminate these contaminants. In the present work, bismuth-doped zinc ferrite (Bi-ZnFe2O4) nanoparticles (NPs) and bismuth-doped zinc ferrites supported on sulfur-doped graphitic carbon nitride (Bi-ZnFe2O4/S-g-C3N4) (BZFG) photocatalysts were synthesized via a hydrothermal process. SEM, XRD, and FTIR techniques were used to examine the morphological, structural, and bonding characteristics of the synthesized photocatalysts. The photocatalytic competence of the functional BZFG nanocomposites (NCs) was studied against MB under sunlight. The influence of Bi (0.5, 1, 3, 5, 7, 9, and 11 wt.%) doping on the photocatalytic performance of ZnFe2O4 was verified, and the 9%Bi-ZnFe2O4 nanoparticles exhibited the maximum MB degradation. Then, 9%Bi-ZnFe2O4 NPs were homogenized with varying amounts of S-g-C3N4 (10, 30, 50, 60, and 70 wt.%) to further enhance the photocatalytic performance of BZFG NCs. The fabricated Bi-ZnFe2O4/30%S-g-C3N4 (BZFG-30) composite outperformed ZnFe2O4, S-g-C3N4 and other BZFG NCs in terms of photocatalytic performance. The enriched photocatalytic performance of the BZFG NCs might be ascribed to a more efficient transfer and separation of photo-induced charges due to synergic effects at the Bi-ZnFe2O4/S-g-C3N4 interconnection. The proposed modification of ZnFe2O4 using Bi and S-g-C3N4 is effective, inexpensive, and environmentally safe.

Fabrication of Cr-ZnFe2O4/S-g-C3N4 Heterojunction Enriched Charge Separation for Sunlight Responsive Photocatalytic Performance and Antibacterial Study

There has been a lot of interest in the manufacture of stable, high-efficiency photocatalysts. In this study, initially Cr doped ZnFe₂O₄ nanoparticles (NPs) were made via surfactant-assisted hydrothermal technique. Then Cr-ZnFe₂O₄ NPs were modified by incorporating S-g-C₃N₄ to enhance their photocatalytic efficiency. The morphological, structural, and bonding aspects were analyzed by XRD, FTIR, and SEM techniques. The photocatalytic efficiency of the functional Cr-ZnFe₂O₄/S-g-C₃N₄ (ZFG) heterostructure photocatalysts was examined against MB under sunlight. The produced ZFG-50 composite has the best photocatalytic performance, which is 2.4 and 3.5 times better than that of ZnFe₂O₄ and S-g-C₃N₄, respectively. Experiments revealed that the enhanced photocatalytic activity of the ZFG nanocomposite was caused by a more effective transfer and separation of photo-induced charges. The ZFG photocatalyst can use sunlight for treating polluted water, and the proposed modification of ZnFe₂O₄ using Cr and S-g-C₃N₄ is efficient, affordable, and environmentally benign. Under visible light, Gram-positive and Gram-negative bacteria were employed to ZFG-50 NCs’ antimicrobial activity. These ZFG-50 NCs also exhibit excellent antibacterial potential.

Preparation of Bi3Fe0.5Nb1.5O9/g-C3N4 heterojunction photocatalysts and applications in the photocatalytic degradation of 2,4-dichlorophenol in environment

The energy band relationship and the active substances were studied to determine photocatalyst accords with the Z-type transfer mechanism.

Recent advancements of g-C3N4-based magnetic photocatalysts towards the degradation of organic pollutants: a review

Heterogeneous photocatalysis premised on advanced oxidation processes has witnessed a broad application perspective, including water purification and environmental remediation. In particular, the graphitic carbon nitride (g-C₃N₄), an earth-abundant metal-free conjugated polymer, has acquired extensive application scope and interdisciplinary consideration owing to its outstanding structural and physicochemical properties. However, several issues such as the high recombination rate of the photo-generated electron-hole pairs, smaller specific surface area, and lower electrical conductivity curtail the catalytic efficacy of bulk g-C₃N₄. Another challenging task is separating the catalyst from the reaction medium, limiting their reusability and practical applications. Therefore, several methodologies are adopted strategically to tackle these issues. Attention is being paid, especially to the magnetic nanocomposites (NCs) based catalysts to enhance efficiency and proficient reusability property. This review summarizes the latest progress related to the design and development of magnetic g-C₃N₄-based NCs and their utilization in photocatalytic systems. The usefulness of the semiconductor heterojunctions on the catalytic activity, working mechanism, and degradation of pollutants are discussed in detail. The major challenges and prospects of using magnetic g-C₃N₄-based NCs for photocatalytic applications are highlighted in this report.

Enhanced photocatalytic CO2-reduction activity to form CO and CH4 on S-scheme heterostructured ZnFe2O4/Bi2MoO6 photocatalyst

A novel ZnFe₂O₄/Bi₂MoO₆ heterojunction photocatalyst was synthesized by a facile solvothermal route. The incorporation of a narrow bandgap ZnFe₂O₄ photocatalyst can efficiently improve the range of light response and light absorption capacity of the Bi₂MoO₆ via the formation of a hybrid structure at the interface. The formed hybrid interface facilitates the separation efficiency of photo-generated carriers at ZnFe₂O₄/Bi₂MoO₆ heterojunction significantly. The experimental results confirm that ZnFe₂O₄/Bi₂MoO₆-20% heterojunction showed the highest photocatalytic efficiency for CO₂ reduction. Specifically, the total product yield of 47.1 μmol g^-1 under 5 h simulated sunlight irradiation is measured in the counterparts of pure ZnFe₂O₄ (14.79 μmol g^-1) and pure Bi₂MoO₆ (19.01 μmol g^-1). Indeed, the formation of ZnFe₂O₄/Bi₂MoO₆ heterojunction improved the photocatalytic efficiency for CO₂ reduction.

A rational design of g-C3N4-based ternary composite for highly efficient H2 generation and 2,4-DCP degradation

In this work, g-C₃N₄ based ternary composite (CeO₂/CN/NH₂-MIL-101(Fe)) has been fabricated via hydrothermal and wet-chemical methods. The composite showed superior photoactivities for H₂O reduction to produce H₂ and 2,4-dichlorophenol (2,4-DCP) degradation. The amount of H₂ evolved over the composite under visible and UV-visible irradiations is 147.4 µmol·g^-1·h^-1 and 556.2 µmol·g^-1·h^-1, respectively. Further, the photocatalyst degraded 87% of 2,4-DCP in 2 hrs under visible light irradiations. The improved photoactivities are accredited to the synergistic-effects caused by the proper band alignment with close interfacial contact of the three components that significantly promoted charge transfer and separation. The 2,4-DCP degradation over the composite is dominated by OH radical rather than h⁺ and O₂^- as investigated by scavenger trapping experiments. This is further supported by the electron para-magnetic resonance (EPR) study. This work provides new directions for the development of g-C₃N₄ based highly efficient ternary composite materials for clean energy generation and pollution control.

An innovative magnetic Ni0.1Co0.9Fe2O4/g-C3N4 nano-micro-spherical heterojunction composite photocatalyst with an extraordinarily prominent visible-light-irradiation degradation performance toward organic pollutants

Environmental pollution removal is attracting more attention these days because of increasing environmental problems. The use of photodegradation catalysts is a promising avenue in resolving environmental issues and therefore high-performance photocatalysts are urgently needed. Herein, we solvothermally synthesized a micro-spherical g-C3N4 photocatalyst and a nanospherical Ni0.1Co0.9Fe2O4 photocatalyst, and then innovatively employed small amounts of Ni0.1Co0.9Fe2O4 nanospheres coupled with g-C3N4 microspheres to fabricate a novel magnetic Ni0.1Co0.9Fe2O4/g-C3N4 nano-micro-spherical heterojunction photocatalyst through post co-calcination. Various techniques, including scanning electron microscopy, transmission electron microscopy, X-ray diffraction, Fourier transform-infrared spectroscopy and UV-vis diffuse reflectance spectroscopy, were employed to analyze the as-synthesized hybrid photocatalyst. The resultant photocatalyst exhibits a record high photocatalytic degradation activity against methylene blue under visible-light irradiation with a 100% degradation rate within only 10 min, corresponding to an extraordinarily prominent degradation reaction rate constant k value of up to 0.586 min-1. Our strategy opens a new effective way for fabricating high-performance photocatalysts and our novel Ni0.1Co0.9Fe2O4/g-C3N4 heterojunction photocatalyst is of great potential for application in environmental treatments.