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Water borne emerging pollutants represents a significant challenge confronting the modern society. As a result of excessive use of dyes and pigments by the textile and other industries, substantial amount of these toxic and recalcitrant substances are widely dispersed into the aquatic sources that may raise serious health issues to all life forms besides causing potential disruption to the ecosystem. Treatments of these hazardous and non-biodegradable organic contaminants in wastewater effluents have become a focal point for researchers dedicated to environmental remediation. Notably, Metal organic frameworks (MOFs) and their composites have been reported to be promising materials for tackling such challenges. This review is dedicated to provide a concise overview by consolidating the diverse beneficial attributes of Cu-BTC MOF rendering it as a versatile material with applications spanning diverse domains, focusing on the reactivity, the role of the metal ion and its recent potential for addressing the elimination of toxic textile dye wastes from the wastewater effluent. Furthermore, it also documents the underlying mechanistic pathway governing the degradation mechanism and the superior electron transport property of Cu ̶ BTC, besides painting in detail the existing limitations that hinder their applicability at an industrial platform. Moreover, a set of future research outlooks serving as a roadmap for exploring the potentiality of Cu ̶ BTC MOFs have also been presented.

Water contamination is a global concern as a result of growing industrialization and urbanization. Dye waste produced by numerous industries pollutes the water, so dye-based wastewater is a major alarm for animals, human health, and the environment. The elimination of these dye contaminants from water supplies is currently critical and significant due to the dyes' toxicity on humans, livestock, and plants. To remove/degrade dyes, various methods have been investigated, including extraction, absorption, membrane separation, coagulation, adsorption, biological treatment, and advanced oxidation process (AOPs). Graphitic carbon nitride (g-C3N4), a captivating formed polymer, has been transformed as an intriguing issue in AOP science because of its metal-free advantages and its high sensitivity to light. Accordingly, when AOPs are joined with g-C3N4, superb dye degradation has occurred. This paper overviewed the g-C3N4-based AOPs are discussed for dye removal. The synergist effectiveness and mechanisms behind catalytic activity of g-C3N4-based catalysts are broadly discussed. In the meantime, the impacts of pH, water temperature, dissolved oxygen, initial dye concentration, catalyst dosage, and scavengers on the reaction carried out by g-C3N4-based catalysts are illustrated.

Pharmaceutical residues in aquatic environments have the potential to induce bacterial resistance, subsequently complicating disease treatment and posing a substantial hazard to public health. This study demonstrates the production of carbon dots from Cassia fistula flowers using a hydrothermal process. The obtained carbon dots were then mixed with zinc oxide to create CDs@ZnO-H400. This heterojunction photocatalyst exhibited notable enhancement in photocatalytic performance due to improved charge separation efficiency at the interface. The CDs@ZnO-H400 catalyst effectively removed two medications, ciprofloxacin and paracetamol. Ciprofloxacin showed maximum photocatalytic efficiency, with 99.8 % degradation, while paracetamol exhibited a degradation efficiency of 75.1 %. The stability of the synthesized photocatalyst was evaluated across four usage cycles using EDX-SEM, FTIR, and XRD techniques. The CDs@ZnO-H400 heterostructure photocatalyst maintained strong photoactivity even after the fourth cycle of usage.

This study investigates the photodegradation efficiency of core/shell structures comprising NiFe2O4/MgFe2O4 (NiF/MgF) and Z-scheme NiFe2O4/Ag/MgFe2O4 (NiF/Ag/MgF) heterojunctions for Methylene Blue dye degradation. In this study, solar radiation was used as a source of excitation. X-ray diffraction analysis reveals an increase in particle size and micro-strain for NiF/MgF and NiF/Ag/MgF, confirming the formation of core/shell structures. The NiF/Ag/MgF sample exhibits the highest magnetization, attributed to the RKKY magnetic interaction between NiF and MgF moments via the conduction electron of the Ag metal layer. Optical measurements indicate increased absorption coefficient and absorption bandwidth for core–shell structures. Photocatalytic activity measurements demonstrate that while bare MgFe2O4 MgF shows limited photodegradation efficiency, NiF/MgF and NiF/Ag/MgF heterojunctions significantly enhance photodegradation. The presence of the Ag metal layer in the NiF/Ag/MgF heterojunction reduces electron-hole pair recombination and enhances their separation, leading to exceptional photodegradation efficiency. These results highlight the significance of Z-scheme heterojunction configurations in augmenting photodegradation processes under solar radiation, offering notable economic advantages. Additionally, the high magnetization observed in the studied samples presents an opportunity for efficient waste material retrieval using a simple magnetic extraction method.

Tryptophan capped Silver nanoparticles (AgNPs) were synthesized through a sonochemical method, utilizing tryptophan as a biocompatible and non-toxic capping agent. Based on UV–visible spectra, the optical band gap of the nanoparticles was found to be roughly 3.01 eV. The TEM and XRD measurements of the particle sizes showed a range of 10–22 nm. Under sun irradiation, these nanoparticles showed notable photocatalytic activity, destroying Methylene Blue (MB) dye by more than 79.4 %. With a pseudo-first-order apparent rate constant of 1.5×10−2min-1, the degradation kinetics were observed. The photocatalysis of MB dye was investigated using liquid chromatography in conjunction with electrospray ionization time-of-flight mass spectrometry (LC-ESI-TOF-MS) to determine the products generated and to clarify the degradation processes. Additionally, the antibacterial, anticancer potential showed thate the nanoparticles exhibited good antibacterial and notable anticancer properties. Furthermore, the antidiabetic activity was investigated through α-glucosidase inhibition, demonstrating a significant inhibition rate of 53.98 %. Antioxidant capabilities were also tested using ABTS and DPPH assays, revealing antioxidant activities of 73.9 % and 52.04 %, respectively. Overall, the synthesized tryptophan-capped AgNPs show promising applications in environmental remediation, as well as potential therapeutic uses.

The growing interest in combining the photocatalytic properties of semiconductors like ZnO and TiO2 with the superior electron conduction capabilities of graphene has resulted in the successful synthesis of in-situ reduced graphene oxide (rGO) supported ZnO-TiO2 nanostructures through a simple microwave-assisted synthesis method. X-ray Diffraction Spectroscopy (XRD), Field Emission Scanning Electron Microscope (FESEM), UV–visible spectroscopy (UV–vis), and Fourier Transform Infrared Spectroscopy (FTIR) were employed to characterize structural, morphological and optical properties as well as surface functional groups of the synthesized products. The XRD measurements of our synthesized samples confirm both structural crystallinity and phase purity, while the FTIR analysis verifies the complete reduction of graphene oxide (GO) to reduced graphene oxide (rGO). The synthesized ternary nanocomposite ZnO-TiO2-rGO exhibited a remarkable 100 % adsorption-assisted removal efficiency for 20 mg/L methylene blue (MB) dye under ultraviolet light illumination within 120 min, along with a 56 % dye adsorption removal efficiency in the same time interval. In comparison, pure ZnO showed 0 % adsorption and only 31 % photocatalytic efficiency at the similar condition. Remarkably, the ZnO-TiO2-rGO nanocomposite exhibited exceptional photocatalytic activity mediated by adsorption, achieving complete degradation of MB dye within 5 min under sunlight irradiation. The photocatalytic efficiency and dye adsorption capacity were found to be significantly lower for the anionic dye methyl orange (MO) compared to the cationic MB dye. The study thoroughly investigated the influence of catalyst dose and initial dye concentration on photodegradation. The proposed mechanism indicates that the extensive surface area and numerous active sites on the rGO promote adsorption, which is then followed by degradation through the metal oxides. Overall, the results unveil that the microwave-assisted synthesis of ZnO-TiO2-rGO nanocomposite is a promising and environmentally friendly approach for efficiently degrading dyes from contaminated wastewater using both UV light and natural sunlight irradiation.

A nanocomposite of hydroxyapatite-supported Ag3PO4 (Ag3PO4/HA) was prepared by in-situ co-precipitation followed by hydrothermal method by utilizing cockle (Anadara granosa) shell as biogenic calcium source. The obtained nanocomposite was characterized by different instrumental analyses. X-ray diffraction spectroscopy, transmission electron microscopy, and X-ray photoelectron spectroscopy analyses confirmed the formation of dispersed Ag3PO4 on HA structure with the particles size ranging at 10–40 nm. The material has band gap energy of 2.3 eV which support the activity as photocatalyst for rhodamine B degradation. The removal efficiency of 99.87% was expressed by the nanocomposite for 120 min of treatment, and reusability was demonstrated by insignificant change of the removal and kinetics constant for 5 cycles. The nanocomposite showed antibacterial activity against E. Coli, S. aureus, K. Pneumonia, and S. pyogenes.

In this study, nanocomposite of nickel nanoparticles-embedded biochar (Ni@BC) was prepared by one-pot pyrolysis method. The role of Ni content to the physicochemical character relevant to adsorption, catalytic oxidation and photocatalytic oxidation activities of the nanocomposite was investigated. The instrumental analyses using X-ray difraction (XRD), scanning electron microscope-energy dispersive x-ray fluorescence (SEM-EDX), transmission electron microscope (TEM), vibrating sample magnetometry, X-ray photoelectron spectroscopy (XPS), and gas sorption analysis were employed to analyze the features of nanocomposite, meanwhile the photocatalytic oxidation of methyl orange (MO) was chosen to evaluate the photocatalytic performance of the nanocomposite. The instrumental analysis results suggest that single phase of dispersed-nickel nanoparticles onto biochar structure was obtained by Ni content of 5, 10, and 30 % wt. With a mean particle's size of 50 nm. From XRD analysis, it was obtained that the higher Ni content in the nanocomposite leads to create higher crystallite size, where the Ni content of 5, 10, and 30 %wt. Gave the size of 18.7, 27.8, and 29.5 nm, respectively. The samples exhibited magnetism with saturation magnetization (Ms) ranging at 3.87 emu g−1- 9.87 emu, which the higher Ni content result in higher magnetism. Similarly, higher Ni content corresponded to a higher specific surface area. Highly photoactivity and stability of Ni@BC was expressed by complete (100 %) methyl orange removal for 30 min, and recyclability until 5th use without appreciable physicochemical properties of the nanocomposite.

Bismuth oxyfluoride (BiOF) is an emerging class of material with notable chemical stability, unique layered structure and striking energy band structure. Bi-based semiconductor materials and reduced graphene oxides (rGOs) have attracted considerable attention due to their broad spectrum of potential applications. Herein, we successfully synthesised an efficient photocatalyst comprising BiOF–rGO nanocomposites with embedded Ag nanoparticles using a simple hydrothermal method. The synthesised nanocomposites were characterised through Fourier-transform infrared spectroscopy, X-ray diffraction (XRD), field emission scanning electron microscopy and ultraviolet (UV)–visible spectroscopy. The XRD results indicated the crystalline structures of the BiOF, Ag-doped BiOF and Ag-doped BiOF–rGO composites. Photocatalytic activity assessments focused on the degradation of methylene blue (MB) and methyl orange (MO) dyes under UV-light and sunlight irradiation. The Ag-doped BiOF–rGO composite exhibited significantly enhanced degradation efficiency, achieving 61.81 % and 74.25 % degradation of MB and MO, respectively, after 300 min under UV-light irradiation. On the contrary, pure BiOF demonstrated only 17.63 % and 48.29 % degradation for MB and MO, respectively, under similar conditions. Furthermore, under sunlight irradiation, the Ag-doped BiOF–rGO composite exhibited an MB removal efficiency of 43.87 % after 300 min, whereas pure BiOF showed only 27.47 % under identical conditions. These results underscore the potential of Ag-doped BiOF–rGO composites as highly efficient and adaptable photocatalysts for the photodegradation of organic dyes in industrial wastewater.

Diazinon, an organophosphorus insecticide, is predominantly removed through photodegradation and biodegradation in the environment. However, photodegradation can generate diazoxon, a highly toxic oxidation byproduct, while biodegradation is hard to complete mineralize diazinon, showing limitations in both methods. In this study, we provided an efficient strategy for the complete and harmless removal of diazinon by synergistically employing biodegradation and photodegradation. The diazinon-degrading strain X1 was capable of completely degrading 200 μM of diazinon into 2-isopropyl-6-methyl-4-pyrimidinol (IMP) within 6 h without producing the highly toxic diazoxon. IMP was the only intermediate metabolite in biodegradation process, which cannot be further degraded by strain X1. Through RT-qPCR and prokaryotic expression analyses, the hydrolase OpdB was pinpointed as the key enzyme for diazinon degradation in strain X1. Photodegradation was further used to degrade IMP and a pyridazine ring-opening product of IMP was identified via high resolution mass spectrometry. The acute toxicity of this product to aquatic organisms were 123 times and 6630 times lower than that of diazinon and IMP, respectively. The stepwise application of biodegradation and photodegradation was proved to be a successful approach for the remediation of diazinon and its metabolite IMP. This integrated method ensures the harmless and complete elimination of diazinon and IMP within only 6 h. The research provides a theoretical basis for the efficient and harmless remediation of organophosphorus insecticide residuals in the environment.

Assembly of AgStBu and PhCOOH ligands with the assistance of soluble silver salt CH3COOAg/CF3SO3Ag in methanol, N, N-dimethylformamide (DMF) and dichloromethane solution, yielded two Ag20 cage isomers co-constructed by thiol and carboxylate/sulfonate ligands encapsulating a CO32– anion template, [(CO32–)@Ag20(StBu)10(PhCOO)4(CH3COO)4(DMF)4] (1) and [(CO32–)@Ag20(StBu)10(PhCOO)6(CF3SO3)2(DMF)4]·2DMF (2). The CO32– anion template was generated in situ by fixing atmospheric CO2. The precise structures of 1 and 2 were confirmed by single-crystal X-ray diffractometry (SCXRD). The thermal stability of compounds 1 and 2 was proved by thermogravimetric (TG) analysis, and their solution stability was characterized by nuclear magnetic resonance hydrogen spectroscopy (1H NMR). The absorption spectra, photocurrent responses, and luminescence of compounds 1 and 2 were investigated. In addition, the photodegradation of methylene blue (MB) and cyclic voltammetry characteristic curves of 1 and 2 were also studied.

The degradation of methylene blue dye-contaminated wastewater via photocatalysis is an efficient approach towards environmental remediation. The SrZrO3 perovskite photocatalyst was synthesized using the modified Pechini sol-gel method, and characterized using XRD, FESEM, FTIR, and UV–visible spectrophotometer. Crystallite size obtained by the Scherrer and Williamson-Hall methods were 45.56 and 44.50 nm, respectively. The sample exhibited an orthorhombic crystal structure. The optical bandgap was estimated to be 5.31 eV. Kinetic study for the degradation of methylene blue dye using SrZrO3 in the presence of H2O2 showed complete decontamination of the methylene blue dye in the time interval of 90–120 min under visible light irradiation. The degradation efficiency was above 80.1 % under illumination and less than 40.1 % in dark. Kinetic studies were performed by varying the dose of photocatalyst and initial concentration of methylene blue. It was observed that higher dose of the photocatalyst and lower concentration of the contaminant produced higher rate of degradation. The solution pH 3 and catalysts dosage of 200 mg yielded the highest rate of degradation. The experimental data fitted best into the Psuedosecond order kinetic model with the highest R2 value, indicating a strong linear relationship. The experimental data was subjected into nonlinear error functions, where the Psuedo-second order kinetic model demonstrated lower values of error functions. The results suggest that the prepared SrZrO3 photocatalyst coupled H2O2 is a promising photocatalyst for the decontamination of methylene blue dye under visible light irradiation.

This study aims to synthesize a ternary Fe3O4-NH2-APTES@rGO@SiO2 core–shell magnetic microspheres by modified Stöber technique to photodegrade aqueous phenol under UV-C light effectively. Results of the X-ray diffractogram of the as-synthesized Fe3O4-NH2-APTES@rGO@SiO2 core–shell magnetic microspheres showed the nanoparticles having an average size of 126.00 nm, comparable to 150.00 nm seen in the FESEM micrograph. These sizes were supported by the EDX and FTIR results which verified the presence of Fe3O4, rGO, and SiO2, and the TEM micrograph revealed them to be spherically shaped. Also, the thermally more stable microspheres than the pure individual components and binary nanocomposites were evident in their corresponding TGA thermograms.Similarly, the photoluminescence spectra of the Fe3O4-NH2-APTES@rGO@SiO2 microspheres supported their higher photodegrading ability as a consequence of an extended e-/h+ recombination rate. The microspheres were more effective in photo-catalytically degrading the highest amount of aqueous phenol (∼89 %) than Fe3O4-NH2-APTES@rGO (∼74 %), Fe3O4-NH2-APTES@SiO2 (∼78 %), and pure Fe3O4 (∼62 %), under an optimized condition of 0.2 g/350 mL catalyst loading and 50 ppm of initial phenol concentration. The enhanced photoactivity was ascribed to the high stability and specific surface of SiO2, the synergistic influence of Fe3O4, and the rGO sheet’s rapid electron transport·H2O2 enhanced phenol degradation to 94 %.

The ability of photocatalysis to clean up environmental contamination, notably in the treatment of water and air, has received extensive research. The composite materials synthesized by the coprecipitation method were made of ZnO and graphitic carbon nitride (g-C3N4) with various concentrations of lanthanum doping (La-ZnO). It was discovered that La metal ions were evenly distributed throughout the layered stacking structures of ZnO nanosheet, which had an impact on the band structure and increased the rate of electron-hole separation and visible light absorption. First-principles calculations show that La-doped ZnO-gC3N4 possesses a direct band gap and a type-II band structure with the conduction band minimum and the valence band maximum located in separate layers. A built-in electric field from the gC3N4 to the La-doped ZnO has been established through an analysis of charge density difference, Bader charge, work function, and band alignment. The electron-hole pair becomes spatially separated as a result, which increases the photodegradation activity. High interfacial charge transfer, efficient charge separation and migration, and high visible light optical absorbance were caused by the direct coating of ZnO on an ultra-thin g-C3N4 layer. The 0.6 % La-doped ZnO-gC3N4 degraded 97 % of the bromothymol blue (BB) dye, which was four times higher than the bulk ZnO, which could remove only about 21 % of the dye at the same time. The combined effects of lower photo corrosion, higher solar light usage owing to a hollow structure and heterostructured semiconductor photocatalysis contribute to this increased photocatalytic activity. The capacity of La-doped ZnO/g-C3N4 nanocomposite to effectively break down BB dye via photocatalysis suggests that it has the potential to address the problems associated with dye pollution in water systems.

Photocatalytic degradation of different organic dyes under simulated sun light irradiation found an increasing attention in the recent years. To development of high-efficient photocatalyst, in this work, we prepared NiFe2O4 nanoparticles by the chitosan-assisted route and characterized by FT-IR, XRD, UV–Vis, SEM and TEM analysis. In addition, the photodegradation of methylene blue (MB) as a model wastewater has been studied and the effect of important parameters such as initial pH solution, catalyst dose, initial MB concentration and irradiation time was investigated. The highest degradation of 98.99 % was reported at optimal conditions, initial pH of 10, photocatalyst dose of 0.04 g, initial MB concentration of 50 mg/L and irradiation time of 150 min. The kinetics of the experimental data analysis using the Langmuir-Hinshelwood model, result predicted that the process obeyed from pseudo-first-order with a strong correlation value (R2) of 0.9936, k = 0.03082 min−1 and t1/2 = 22.49 min. Reusability of NiFe2O4 nanoparticles revealed that the degradation efficiency was change from 98.99 % (initially) to 95.68 % (five cycles). The results predicted that the as-prepared NiFe2O4 nanoparticles showing great photodegradation efficiency towards MB dye, ease of use, good stability and potential to be used as catalyst for photodegradation of other organic dyes.

Semiconductor photocatalyzed energy production and environment treatment have received a lot of attention. Mn–Cd–S solid solutions (MnxCd1−xS) with tunable band structure, suitable redox capacity, and visible light response is recognized as one of the most promising photocatalysts for practical applications. However, low separation efficiency of photogenerated carriers and sluggish reaction kinetics restricts its photocatalytic activity. This review discusses the advantages and drawbacks of MnxCd1−xS for photocatalysis in terms of electronic band structure and surveys the modification strategies of photocatalytic activity, including modulation of Mn/Cd ratio, morphology/structure regulation, defect engineering, construction of heterojunction, loading cocatalysts, and integration of multiple strategies. Then, the progress in photocatalytic water splitting to hydrogen, carbon dioxide reduction, and pollutant degradation using MnxCd1−xS-based materials are summarized. Finally, it is concluded by outlining the challenges and opportunities for developing efficient photocatalysts based on MnxCd1−xS.

This study addresses the challenging issue of water pollution caused by the non-biodegradable organic compound methylene blue (MB) by synthesizing Fe3O4/SiO2 composite using SiO2 derived from rice husk ash (RHA) for MB photodegradation. The SiO2 was prepared from RHA at various heat treatment temperatures of 750, 800, 850, 900, and 950 °C that resulted in samples A, B, C, D, and E, respectively. The Fe3O4/SiO2 composites were then synthesized using the RHA-derived SiO2 as a precursor, resulting in samples 1 to 5. Various characterizations were conducted, including X-Ray Diffraction (XRD), Scanning Electron Microscopy-Energy Dispersive Spectroscopy (SEM-EDS), Vibrating Sample Magnetometer (VSM), and Fourier Transform Infrared (FTIR). The photodegradation activity of Fe3O4/SiO2 was tested with UV–Visible spectroscopy. XRD pattern of SiO2 derived from RHA revealed a broad diffraction peak at 2θ of 21.52°, confirming the presence of amorphous SiO2. Meanwhile, all of the composite samples showed peaks corresponding to Fe3O4 and SiO2. FTIR analysis of the composite also verified the existence of SiO2 and Fe3O4. SEM images of RHA-derived SiO2 (samples A-E) showed an ununiform shape, while the composite samples showcased a homogeneous morphology. The EDS results showed the RHA-derived SiO2 (samples A-E) consisted of C, O, Si, Zn, and Cl, while Fe3O4/SiO2 composite samples (samples 1–5) comprised elements Fe, O, C, Si, Zn, and Cl. Superparamagnetic properties also showed in Fe3O4/SiO2 samples 1, 3, and 5, according to the VSM analysis with sample 5 exhibiting the highest saturation magnetization. Among the Fe3O4/SiO2 composites, sample 4 exhibited the highest performance as a photocatalyst for degrading MB.

The Cu2O/Cu emerges as a promising candidate for photocatalytic application owing to its efficient photon absorption in the visible light spectrum. However, the susceptibility of Cu2O-based photocatalysts to self-decomposition diminishes their effectiveness. This study introduces CoNi as co-catalyst to enhance the durability of Cu2O/Cu photocatalyst. Electrodeposition was employed to decorate the Cu2O/Cu crystal surface with Co, Ni and CoNi. The deposition potential of CoNi was optimized to produce a high-performance photocatalyst. The utilization of CoNi co-catalyst resulted in significant enhancements in photoelectrochemical properties under light irradiation when compared to using a single Co or Ni co-catalyst, suggesting a synergistic effect between Co and Ni within the system. The enhancement is evidenced by a noteworthy increase in the photocurrent of the photocatalyst, rising from 10.24 mA/cm2 to 20.81 mA/cm2. In addition, the decoration of CoNi resulted in a reduction of the charge transfer resistance from 4.2 kΩ to 0.7 kΩ, while simultaneously increasing the electrochemically active surface area of the photocatalyst from 15.49 cm2 to 157.69 cm2. The observed modifications lead to a substantial improvement in the photocatalytic efficiency, resulting in an impressive 88 % degradation of methylene blue, which is 3.4 times higher than achieved in the absence of the co-catalyst. Moreover, there was a significant improvement in the photostability of the photocatalyst, with an increase from 16.81 % to 50.55 %. These findings demonstrate the significance of CoNi co-catalyst decoration in producing a highly active and durable photocatalyst, making it a promising candidate for efficient synthetic dyes degradation.

One of the world's most important challenges is the lack of access to clean water, and researchers are working tirelessly to find a solution. Nanotechnology-treated water is superior to conventionally treated water since it contains no hazardous microorganisms or organic dyes. In this study, the influence of light on Ag3VO4 nanocomposites doped with synthesized ZnO nanoparticles was analyzed. SEM, FTIR, XRD, XPS, and UV–vis spectroscopy were just some of the methods used to characterize the as-prepared nanocomposites. An Ag3VO4/ZnO nanocomposite was used to successfully adsorb and photodegrade Acid Green-16(AG-16), and Acid Red-72(AR-72) from an aqueous solution. Visible light dramatically accelerates the adsorption and photodegradation of the Ag3VO4/ZnO nanocomposite compared to complete darkness. 77.52 %, 82.86 %, and 89.56 % of AG-16 and 77.11 %, 82.74 %, and 87.91 % of AR-72 were removed by the ZnO, Ag3VO4, and Ag3VO4/ZnO nanocomposites, respectively, in less than 60 min. However, visible-light photodegradation is more successful than adsorption alone in removing AG-16 and AR-72. In this pioneering study, we assess the catalytic performance of newly synthesized ZnO incorporated Ag3VO4 nanocomposites for the UV-assisted degradation of organic dyes. Our study presents an innovative catalyst system that exhibits improved efficiency and holds promise for implementation in environmentally sustainable wastewater treatment methods.

Organic dyes are a major source of environmental pollution from different industries. To remove these recalcitrant, a novel ternary g-C3N4/ZnO/Ag2CrO4 and its polyaniline-supported (PANI) composites were synthesized using an “in situ” oxidative polymerization approach. XRD, SEM, UV–Vis DRS, and PL techniques were utilized to characterize the as-prepared composites. The photocatalytic efficiency was evaluated using a model organic pollutant, methylene blue (MB), and samples of the effluent of the textile industry. The as-synthesized ternary g-C3N4/ZnO/Ag2CrO4 (ZT3= 87.87 %) composite showed better photocatalytic performance than the single (5 %) and binaries (15–25 %) counterparts for MB degradation. The influence of various experimental settings on the photodegradation of MB dye was examined and these were an initial dye amount of 10 ppm, photocatalyst load of 0.15 g/L, and pH 10. Under optimized conditions, PANI-supported g-C3N4/ZnO/Ag2CrO4 composite (PAST) demonstrated substantial degradation efficiency (97.5 %). The reusability study of the spent catalyst revealed a reduced efficiency from 97.5 to 78.5 % photodegradation of MB after four successive cycles, demonstrating the photocatalyst's stability and efficiency. According to the study on the effect of scavengers, h+ plays a significant part in the discoloration of MB. The PAST photocatalyst outperformed the MB discoloration (97.5 %) and adequate degradation for real textile effluent samples (77.7 %) collected from Hawassa textile industries. The photodegradation efficiency result of this study demonstrated that PANI-supported g-C3N4/ZnO/Ag2CrO4 might serve as an advantageous photocatalyst for the efficient removal of MB and other dyes under visible light irradiation at the optimum conditions. The total estimated cost analysis of synthesis and photocatalytic degradation using Polyaniline-supported g-C3N4/ZnO/Ag2CrO4 composite found that it was quite affordable, costing around $5 per 1,000 L of wastewater treatment.

The preparation of MgAl Layer Double Hydroxide (LDH) was performed using the coprecipitation method. Pristine MgAl LDH was calcined at 500 °C to produce the MgAl Layer Double Oxide (LDO). The two materials were modified via restacking-delaminating the bioactive compounds from the flower extract of Clitoria ternatea (CT) to produce MgAl LDHCT and MgAl LDOCT. Modifications are performed to enhance the stability of the catalyst structure, allowing its higher photocatalytic activities and regeneration use. The prepared catalysts were characterized using XRD, FT-IR, UV-DRS, BET, and SEM-EDX. The XRD diffraction pattern showed that the three catalysts have typical diffraction patterns commonly observed in LDH-based materials. FT-IR spectra confirmed that MgAl LDHCT and MgAl LDOCT showed combined spectra of its precursor materials. MgAl LDOCT has the lowest bandgap energy with the highest degradation kinetics. BET and SEM-EDX characterization shows uniform surface and pore size on MgAl LDOCT. The prepared catalysts were used in the ciprofloxacin photodegradation under UV light. The optimal catalyst dose was 5 mg, while the optimal pH was 5. MgAl LDOCT, MgAl LDHCT, and MgAl LDH showed ciprofloxacin degradation capacity up to 73.300%, 65.739%, and 71.320%, respectively, within 120 min. Repeated use of the catalyst up to the third cycle resulted in%R reaching 80.871%, 74.003%, and 52.025%, respectively, by MgAl LDHCT, MgAl LDOCT, and MgAl LDH. Compared to pristine MgAl LDH, the CT intercalated catalysts exhibited more excellent stability.

To accurately, efficiently, and environmentally prepare carrageenan oligosaccharides, we have developed a method that uses H2O2 and TiO2 as catalysts for the photodegradation of κ-carrageenan (KC). The photodegradation of KC was monitored using various amounts of TiO2 and H2O2 and different concentrations of KC via HPLC and it could decrease the average molecular weight of KC into 1.6 kDa within 2 h. Further research under optimal conditions. As a control, the effects of UV, UV/H2O2, UV/TiO2, and H2O2/TiO2 treatments were studied. In contrast, UV/H2O2/TiO2 treatments showed a coordinated effect. The effect of degradation on the structure of KC was investigated by FT-IR, XRD, and there was no obvious remotion of sulfate groups. Furthermore, oral administration of KCO prolonged the healthy lifespan of nematodes induced by ultraviolet stress and significantly regulated oxidative stress. This study suggests that the precise preparation and application of KCO may be beneficial.

The primary focus of the work is to study the structural, optical, dielectric and antibacterial properties of ZnO-MoS2 nanocomposite synthesized wet-chemically. X-ray diffraction (XRD) examination confirmed the development of ZnO-MoS2 nanocomposite, revealing characteristic diffraction peaks corresponding to both ZnO and MoS2 phases. Transmission electron microscopy (TEM) investigation showed a well-dispersed distribution of ZnO and MoS2 nanoparticles, and energy dispersive x-ray analysis (EDAX) confirmed the elemental (Zn, O, Mo, S) existence in ZnO-MoS2. The chemical composition and electronic states were confirmed using x-ray photoelectron spectroscopy (XPS). Dielectric experiments illustrate a decrease in the dielectric constant value with a lower loss tangent with increasing frequency. The addition of MoS2 to the ZnO matrix had a substantial impact on the dielectric characteristics of ZnO-MoS2, resulting in an increase in the dielectric constant and a decrease in the dielectric loss. AC conductivity increases with frequency, and these findings indicate that ZnO-MoS2 nanocomposites may find potential applications in electrical and optoelectronic devices. The photocatalytic performance was tested by degrading model dyes (methylene blue and Congo red) under UV–Vis light. The synergistic interactions between ZnO and MoS2 give the nanocomposite better photocatalytic properties than pure ZnO and MoS2. The heterojunction interface promotes charge separation and reactive oxygen species generation, improving photocatalytic efficiency. The antibacterial capability was also tested by diffusion method, and nanocomposites were found to outperform pristine samples in inhibiting bacterial growth.

Photocatalytic responses and synergistic effects of V2O5, TiO2, and V2O5/TiO2 heterostructures with varied ratios have been investigated, revealing promising outcomes. The successful synthesis of nanostructures and heterostructures was verified through energy-dispersive X-ray spectroscopy, X-ray diffraction, and Fourier transform infrared spectroscopy analyses. Notably, ultraviolet–visible spectroscopy and photoluminescence spectral studies confirmed that the optical band gap of V2O5/TiO2 heterostructures increases with higher TiO2 concentrations. These findings enhance our understanding of the agglomerated heterostructures of V2O5/TiO2, particularly with ratios of 1:1 and 1:3, showcasing potential applications in photocatalysis. Furthermore, their performance was subjected to Malachite Green dye degradation using a solar simulator, achieving an impressive efficiency of 93.29%. Additionally, the photocatalytic efficacy was assessed through reusability experiments over three cycles. Remarkably, the heterostructures exhibited stability across these cycles, suggesting their potential for extended use in diverse photocatalytic purposes. The importance of these results is the applicability of our fabricated V2O5/TiO2 heterostructures as a photocatalyst with high performance, especially in the realm of sustainable and efficient dye degradation processes.

Developing multifunctional nanomaterials through environmentally friendly and efficient approaches is a pivotal focus in nanotechnology. This study aimed to employ a biogenic method to synthesize multifunctional copper oxide nanoparticles (LI-CuO NPs) with diverse capabilities, including antibacterial, antioxidant, and seed priming properties, as well as photocatalytic organic dye degradation and wastewater treatment potentials using Lagerstroemia indica leaf extract. The synthesized LI-CuO NPs were extensively characterized using UV–vis spectroscopy, dynamic light scattering (DLS), X-ray diffraction (XRD), scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform-infrared spectroscopy (FT-IR). The colloid displayed surface plasmon resonance peaks at 320 nm, characteristic of LI-CuO NPs. DLS analysis revealed an average particle size of 93.5 nm and a negative zeta potential of −20.3 mV. FTIR and XPS analyses demonstrated that LI-CuO NPs possessed abundant functional groups that acted as stabilizing agents. XRD analysis indicated pure crystalline and spherical LI-CuO NPs measuring 36 nm in size. Antibacterial tests exhibited significant differential activity of LI-CuO NPs against both gram-negative (Escherichia coli, Salmonella typhimurium) and gram-positive (Staphylococcus aureus and Listeria monocytogenes) bacteria. In antioxidant tests, the LI-CuO NPs demonstrated a remarkable radical scavenging activity of 97.6 % at a concentration of 400 μg mL−1. These nanoparticles were also found to enhance mustard seed germination at low concentrations. With a remarkable reusability, LI-CuO NPs exhibited excellent photocatalytic performance, with a degradation efficiency of 97.6 % at 150 μg/mL as well as a 95.6 % reduction in turbidity when applied to wastewater treatment. In conclusion, this study presents environmentally friendly method for the facile synthesis of LI-CuO NPs that could potentially offer promising applications in biomedicine, agriculture, and environmental remediation due to their multifunctional properties.

The ternary photocatalyst ((Al2Si2O5 (OH)4/TiO2/Al2O3) composites (where w/w = 65, 30, and 5 wt%) denoted K65T30A5 were successfully synthesized and examined for their efficiency in removing cationic (Methylene Blue, MB) and anionic (Remazol Red, RR) dye from aqueous medium under visible-light irradiation. A series of nanocomposites with varied wt% of kaolinite, TiO2, and Al2O3 were prepared through sonication followed by calcination at 600 °C. X-ray diffraction (XRD) analysis confirmed the crystallinity of the synthesized materials and established their average crystal size to be 83.87 nm. The morphological structure, composite molecule, and surface properties of the resulting K65T30A5 were characterized using FTIR, FE-SEM, and EDS analyses to confirm the successful fabrication of the nanocomposite. FTIR and EDS elemental mapping analyses confirmed the presence of Al, Si, Ti, and O elements in the nanocomposites. The composites exhibited photocatalytic behaviour across the UV–visible spectra, with values varying from the ultraviolet to the visible region with a sharp increase in reflectance at 510 nm. Near-complete degradation of MB (97.66 %) was achieved within 90 min at pH 9 and a 10 mg/L dye concentration, while RR removal reached 90.66 % within 120 min at pH 3.5 and the same dye concentration under visible light irradiation. The catalyst exhibited robust stability, retaining its efficiency by removing 85.09 % of MB and 80.21 % of RR dye after three reuse cycles. The composite catalyst discussed in this study emerges as a promising material for straightforward fabrication techniques, featuring a high percentage of kaolinite and proving to be a cost-effective solution for large-scale water and wastewater treatment processes.

PVDF-ZnO nanocomposites, prepared through phase separation-assisted nanoprecipitation with varying ZnO concentrations, exhibit enhanced photocatalytic performance against organic dye pollutants. Comprehensive characterization methods, including X-ray diffraction, spectroscopic and microscopic analyses, and thermal stability studies, are employed to assess the microspheres of phase-separated PVDF composites. Band gap analysis and optical characteristics of the nanocomposites are studied using Tauc's plots. The band gap energy of ZnO is determined as 3.47 eV, and the microsphere diameter averages between 0.23 and 0.24 μm. The incorporation of 1–3 wt% ZnO increases the decomposition temperature to approximately 480 °C. Photocatalytic performance tests utilizing various organic dye pollutants such as Methyl Orange (MO), Thymol Blue (TB), and Cresol Red (CR) reveal significant degradation efficiencies of 86 %, 84 %, and 35 %, respectively, under natural sunlight exposure. Despite the reduction in crystallinity of the phase-separated PVDF particles with the addition of ZnO, notable enhancements in the photocatalytic activity are achieved for the composites. Phase separation provides a synergistic interaction between the aligned polymer chains and the ZnO nanoparticles, contributing to the high degradation efficiency. Moreover, the presence of ZnO active photocatalytic sites induces active dye degradation. The study showcases the potentiality of PVDF/ZnO nanocomposites in photocatalytic dye degradation, with recoverability of composite particles from dye solutions, a simple composite development method, and direct exposure to natural sunlight. Significant implications are anticipated in pollution control and environmental remediation through the purification of industrial wastewater.

Various integrated technologies have been investigated for the remediation of heavily polluted industrial dye effluent. Also, more than 70 % of these dyes are known to be solely azo dyes used in the textile industry with 5–30 % presence in the effluent as loose dye molecules which are recalcitrant to treatment. These challenges led to the investigation of energy-efficient processes (solar) and the fabrication of high-performance nano-photocatalysts for proficient photocatalysis of dye effluent while mediating the process with Fenton reagents. The study fabricated nanopolymeric catalyst composites (P-AKT) via novel in situ coupling and impregnation of the polyaniline (PANI) with surface-activated TiO2 NPs. This fabrication is aimed at developing a high-performance catalyst with rapid and proficient photocatalytic activities to photons from sunlight irradiation. The photocatalytic process was mediated using a novel Fenton reagent to enhance the generation of radical species for dye degradation. Various instrumental characterization methods were used to study the structural, molecular, elemental, functional and optoelectronic properties of the fabricated nanocomposite photocatalysts. The result reveals functional groups aiding dye-catalyst bonding and morphological interaction reveal a surface-activated tetragonal crystalline mixture of anatase and rutile from TiO2−Nps embedded in the macromolecular chain of PANI. It also reveals the optimal conditions of 20 mg dosage, 10 mg/L initial concentration with substantial effectiveness at pH of 5 and 7. However, the most efficient photocatalyst recorded was P-AKT-2 % and P-AKT-3 % having 95 % and 94 % efficiencies at 90 min of solar irradiation. The photocatalyst equally demonstrated its capacity for effluent treatability up to 4 cycles of use.

Using Rhodamine-B (Rh B) as a model organic molecule, a co-precipitation-oxidation-mediated synthesis of cobalt-substituted zinc spinel ferrites (CoxZn1-xFe2O4, x = 0 to 1) is described. Multiple methods (XRD, DRS, EDX, VSM, BET, and FESEM) were used to evaluate the synthesized cobalt zinc ferrites. The material Co0.5Zn0.5Fe2O4, which had pore diameters ranging from 3 to 50 nm and a minor peak centered at about 35 nm, displayed non-uniform shapes and sizes of the porous materials made by the aggregation of ferrite nanoparticles. The SBET Brunauer-Emmett-Teller (BET) surface area values were 10.05, 13.47, and 10.9 m2/g for ferrites, zinc ferrites, and cobalt-zinc ferrites, respectively. It was found that under ideal conditions, 99% of the Rh B dye was destroyed by the Co0.3Zn0.7Fe2O4 (x = 0.3) sample within 180 min of exposure to visible light. Scavenger testing and fluorescence spectroscopy confirmed that OH and holes were the principal reactive radicals involved in the degradation process. The performance of a Co0.3Zn0.7Fe2O4 photocatalyst was almost unchanged after being cycled for five consecutive cycles. Therefore, it was concluded that these photocatalysts are superior options for treating Rh B-tainted wastewater under optimum conditions (pH = 2, dose catalyst = 0.1 mg/L, concentration of pollutant = 20 mg/L, with 120 mM of hydrogen peroxide).

Photoactive metal on graphitic mesoporous carbon (GMC-M; M=Fe, Ni, Fe-Ni and Co-Ni) was obtained from hard templating synthesis method while using sucrose as carbon precursor. Sucrose was deposited on metal/SBA-15 followed with carbonization and pyrolysis to obtain readily incorporated Fe, Ni, Fe-Ni and Co-Ni on GMC. GMC-M was characterized using XRD, FTIR, N2 Adsorption Desorption and Raman spectroscopy. All the analytical results showed the mesoporous carbon has a highly ordered graphitic structure which was proven by Raman that shows an increase in the ratio of ID/IG from ordinary GMC to GMC-M (M=Fe, Co, Ni) as a phenomenon of increasing structural regularity. The photodegradation activity of GMC-M was investigated for degradation of methylene blue (MB) in synthetic wastewater. The photodegradation of MB was carried out under ultraviolet light (UV) irradiation and in the presence of hydrogen peroxide (H2O2). All the catalysts partially degraded methylene blue within 60 min with the efficiency varied 40% to 80% MB, indicating the promotion of GMC into photoactive material with metal addition. Degradation of MB under UV-H2O2 using GMC-Fe system resulted in 96% efficiency than the UV only. The present study showed that the UV-oxidant/catalyst process significantly enhanced the degradation of MB in comparison to direct photolysis by UV.

In this study, an integral treatment consisted of UV/Fenton/ TiO2 system in the batch systems was developed to perform degradation of synthetic Benzene, Toluene, Ethyl Benzene, and Xylene (BTEX). Initially, the efficiency of photo Fenton catalytic degradation was compared with conventional treatment methods. Later, optimum levels of selected variables such as the initial concentration of BTEX, pH, temperature, reaction time, and initial dosage of TiO2 were analyzed using one factor at a time method. Further, screening of variables and optimization were performed using Planckett-Burman design and central composite design, respectively. Photo Fenton catalytic process showed about 1.15 fold increase in efficiency when compared with photo Fenton process. Among the selected seven variables, four variables namely, initial pH, BTEX concentration, H2O2 dosage and TiO2 dosage were identified as significant factors. Under the optimal conditions, chemical oxygen demand reduction reached about 84.54 ± 2.57% using UV/Fenton/ TiO2 system. Finally, first-order kinetic model resulted in prediction of 19.43 kJ/mol of activation energy. Thus, process optimization and kinetic study using the developed photo Fenton catalytic system could be beneficial for real time waste containing BTEX pollutants.

Pure and manganese-doped titanium dioxide nanoparticles (MnTiO2-NPs) were synthesized by the defect-oriented hydrothermal approach. The synthesized material was then characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM), Energy dispersive X-ray spectroscopy (EDX), and UV–visible spectroscopy (UV–Vis). The agar well diffusion method assessed the antibacterial efficiency of TiO2 and MnTiO2-NPs against E. coli and S. aureus. Zone of inhibition (ZOI) formed by pure TiO2 was observed as 12 mm and 11.5 mm against E. coli and S. aureus, while for MnTiO2-NPs it was observed as 19 mm (E. coli) and 21 mm (S. aureus). The concentration of synthesized nanoparticles (10 mg/ml, and 20 mg/ml) was used for antibacterial studies. The efficacy of the pure and MnTiO2-NPs as an active photocatalyst for the degradation of methylene blue (MB) dye was also assessed using a UV light. It was observed that the photodegradation efficiency of 1 g of MnTiO2-NPs was higher than the same amount of pure TiO2. The results suggest that the photocatalyst concentration directly impacts the photodegradation of MB dye. The pH value was found to influence the photodegradation of MB dye at higher pH values. Based on the obtained results, MnTiO2-NPs were observed as a promising agent for microbial resistance and water remediation.

In the present work, Zinc-oxide nanostructures and Ce/Zinc-oxide nanopetals were synthesized by a new environmentally friendly green synthesis method using the Withania coagulans plant. Cerium nitrate Ce(NO3)3 and zinc nitrate Zn(NO3)2 were used as precursors. The prepared nanostructures were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet spectroscopy (UV–vis). Crystal planes (100), (002), (101), (102), (110), (103), (200), (112) and (201) at 2θ 31.75°, 34.35°, 36.2°, 47.55°, 56.6°, 62.75°, 66.3°, 67.9°, and 69.09° respectively confirmed the hexagonal wurtzite crystal structure of Zinc-oxide. Angular shifts for Ce1% doped Zinc-oxide and Ce3% doped Zinc-oxide nanopetal nanostructures were observed in the (100) and (101) planes of the crystal. More specifically, using Scherrer's equation, the crystallite sizes of Zinc-oxide, Ce1% doped Zinc-oxide nanopetals, Ce3% doped Zinc-oxide nanopetals, and Ce5% doped Zinc-oxide nanopetals were 16.48 ± 02 nm, 17.8 ± 2 nm, 18.8 ± 2 nm, and 18.87 ± 2 nm, respectively. The pure Zinc-oxide grain had the appearance of a nanoflower. On the other hand, the nanopetal structure of Ce5% doped Zinc-oxide nanopetals had oval-shaped nanopetal morphology. The absorption peaks were observed at 373, 376.4, 377, and 378 nm for Zinc-oxide, Ce1% doped Zinc-oxide nanopetals, Ce3% doped Zinc-oxide nanopetals, and Ce5% doped Zinc-oxide nanopetals, respectively, which results in a progressive redshift. The gap energies of Zinc-oxide, Ce1% doped Zinc-oxide nanopetals, Ce3% doped Zinc-oxide nanopetals, and Ce5% doped Zinc-oxide nanopetals were 2.796, 2.645, 2.534, and 2.448 eV, respectively. Photodegradation under visible light (>400 nm) indicates the high efficiency of the photocatalyst based on Ce5% doped Zinc-oxide nanopetals. DFT calculations, structural changes, charge analysis, and electronic band structures were carried out to confirm the experiment.

This study aimed to investigate the potential of the photocatalytic ozonation process (PCO) for decolorizing DB1(direct blue) dye, a commonly used dye in the textile industry known for its resistance to removal from wastewater. To address this challenge, a ZnSnO3@S-doped g-C3N4 nano photocatalyst was synthesized using a simple hydrothermal method. In a novel approach, a light/O3/ZnSnO3@S-doped g-C3N4 system was employed for the first time to degrade the DB1 dye. BET analysis indicated that the synthesized catalyst exhibited the fifth type of isotherm, typically associated with materials containing mesopores. Under optimized conditions, the PCO process achieved complete decolorization of 70 ppm DB1 dye within just 15 min at a temperature of 25 °C, a gas flow rate of 2.83 ml/s, and a catalyst dosage of 0.003 g, encompassing both removal and photocatalytic contributions. Importantly, the catalyst demonstrated excellent stability and could be reused up to five times. These findings highlight the promising potential of the light/O3/ZnSnO3@S-doped g-C3N4 system in effectively decolorizing DB1 dye, overcoming its resistance, and addressing an important challenge faced by the textile industry in wastewater treatment. The formative nature of this study provides valuable insights into the development of advanced oxidation processes for efficient dye removal.

A novel and efficient bionanocomposite was synthesized by incorporating SnO into chitosan (Ch) and a room-temperature ionic liquid (RTIL). The bionanocomposite was synthesized in benzoyl pyridinium chloride [BzPy]Cl to maintain the unique properties of SnO, chitosan, and the ionic liquid. Adsorption and photodegradation processes were applied to evaluate the bionanocomposite for removing azo and anthraquinone dyes and textile wastewater. SnO/[BzPy]Cl and SnO/[BzPy]Cl/Ch samples were prepared and characterized using various techniques, including FT-IR, SEM, XRD, EDAX, XPS, DSC, TGA, nitrogen adsorption/desorption isotherm, and DRS analysis. SEM analysis revealed a hierarchical roughened rose flower-like morphology for the biocomposite. The band gap energies of SnO/[BzPy]Cl and SnO/[BzPy]Cl/chitosan were found to be 3.9 and 3.3 eV, respectively, indicating a reduction in the band gap energy with the introduction of [BzPy]Cl and chitosan. SnO/[BzPy]Cl/Ch showed high removal rates (92–95 %) for Fast Red, Blue 15, Red 120, Blue 94, Yellow 160, and Acid Orange 7 dyes. The adsorption kinetics followed a pseudo-second-order model.In addition, the effect of different photodegradation parameters such as solution pH, dye concentrations, contact time, and amount of photocatalyst, was studied. Given the optimal results obtained in removing azo and anthraquinone dyes, the SnO/[BzPy]Cl/Ch nanocomposite was used as an efficient nanocomposite for removing dyes from textile wastewater. The highest removal efficiency was found to be 95.8 %, obtained under ultraviolet and visible light. Furthermore, BOD and COD reduction analysis showed significant reductions, indicating the excellent performance of the photocatalyst.

Microplastics (MPs) constitute a serious threat to the environment due to their pervasiveness and potential negative effects on various life forms. The quest for novel methods targeting the degradation of MPs has increased in recent years. Recent studies and research, focussed on techniques like biodegradation, thermal degradation, pyrolization and nanoparticle-mediated microplastic degradation as a prominent way to overcome this issue. In the realm of emerging methodologies, metal-organic frameworks (MOFs) exhibit significant potential for MPs degradation. MOFs are highly porous 2D or 3D materials with a large surface area, adaptable chemical composition, and configurable pore size. These properties render MOFs suitable for the adsorption and degradation of MPs. The efficacy of MOF-mediated MPs degradation is dependent on the type of MOF, size, shape of MPs, and environmental conditions. They are also sustainable, efficient, and adaptable materials, making them suited for MPs degradation. This review examines diverse methodologies for the degradation of MPs, encompassing processes such as hydrolysis, oxidation, photo-degradation, bio-mimicking, phase transformation, and photoelectrochemical mechanisms. Future research prospects on the application of MOFs for MP degradation have also been addressed. MOF-mediated MP degradation is still in its infancy, but it has the potential to represent a significant advancement in this area. The last section of the review covers the field's obstacles and constraints, including ways to use MOFs for microplastic clean-up that are economical, environmentally friendly, and technically comprehensive.

Per- and polyfluoroalkyl substances (PFAS) are oxidatively recalcitrant organic synthetic compounds. PFAS are an exceptional group of chemicals that have significant physical characteristics due to the presence of the most electronegative element (i.e., fluorine). PFAS persist in the environment, bioaccumulate, and have been linked to toxicological impacts. Epidemiological and toxicity studies have shown that PFAS pose environmental and health risks, requiring their complete elimination from the environment. Various separation technologies, including adsorption with activated carbon or ion exchange resin; nanofiltration; reverse osmosis; and destruction methods (e.g., sonolysis, thermally induced reduction, and photocatalytic dissociation) have been evaluated to remove PFAS from drinking water supplies. In this review, we will comprehensively summarize previous reports on the photodegradation of PFAS with a special focus on photocatalysis. Additionally, challenges associated with these approaches along with perspectives on the state-of-the-art approaches will be discussed. Finally, the photocatalytic defluorination mechanism of perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) following complete mineralization will also be examined in detail.

Here we report a novel cage-like silsesquioxane-based porous polymer (PCS-CA) by the amide condensation reaction of octa(3-aminopropyl)silsesquioxane hydrochloride (OAS) with tetrakis(4-carboxyphenyl)porphyrin (HCPP) at room temperature with high yield. PCS-CA shows a high surface area of 452 m2g−1 and hierarchical pore structure with coexistence of micropores and mesopores which can remove heavy metal ions effectively. The resulting PCS-CA-Mn after the complex of PCS-CA with Mn2+ shows an excellent photodegradation ability of Congo Red (CR) and Methyl Orange (MO) in water with ∼ 100% degradation efficiency under sunlight. The possible photodegradation mechanism of PCS-CA-Mn is also proposed. Moreover, PCS-CA and PCS-CA-Mn offer NIR emission at ∼ 740 nm.

The degradation of amoxicillin residue has been performed using TiO2 photocatalyst doped with Cr prepared from tannery wastewater under visible light exposure. The incorporation of Cr metal into TiO2 structure was conducted via hydrothermal method. From the characterization results, it is found that doping Cr from the tannery wastewater into TiO2 structure has been successfully shifted the light absorption into visible region. Among the various Cr content in the TiO2-Cr photocatalyst, TiO2-0.33Cr (medium level) shows the highest ability in the visible light absorption, suggesting it to be the best photocatalyst. It is also clearly proven that in the presence of TiO2-0.33Cr photocatalyst, the degradation of amoxicillin can reach almost 100 % after the third cycles. Furthermore, this study also investigated the optimum condition for photodegradation of amoxicillin as the prevalent antibiotic residue in batch technique. The concentration of amoxicillin after the photodegradation process was determined using a UV–visible spectrophotometer. The result identifies the optimal condition for the amoxicillin photodegradation is reached at pH 6, with 10 mg of the photocatalyst mass per 30 mL of the sample solution, and an irradiation time at 90 min. The photodegradation of amoxicillin using TiO2-0.33Cr follows the pseudo-first order kinetic model with kinetic constant (k) is high as 0.004 min−1.

In this work, nanoparticles of ilmenite powder (47 nm) were prepared via ball-milling of natural ilmenite ore to enhance the specific surface area of particles. The photocatalytic activity of magnetically separable ilmenite nanoparticles was investigated in the degradation of methyl orange (MO) and methylene blue (MB). The Band gap of the ilmenite nanoparticles was calculated 3.05 eV. The photodegradation results show that ilmenite nanoparticles completely destruct MO and MB in 40 and 50 min under visible irradiation. In order to choose of optimum values of factors, the leaching process was optimized by applying a “Rotatable Central Composite Design” (CCD) technique. For preparing of required precursor, the grind ilmenite was crushed into small particles by ball milling method. In addition, in order to purifying the titanium slag, reduction process was carried out. Effective Factors on sulfuric acid process as follows leaching time, temperature, acid concentration and solid/liquid (S/L) ratio, were studied.

The inadequate existence of practical techniques for water purification poses a prominent and widespread global environmental challenge. This study aims to clarify the efficacy of xanthan application in the photocatalytic removal of nadolol, pindolol, and cefoperazone from water reservoirs. Under the influence of a simulated solar light source, xanthan exhibited significant degradation rates for pindolol (77%) and cefoperazone (91%). In contrast, nadolol's degradation efficiency was notably lower (10%). These findings suggest that the molecular structure can substantially influence the efficiency of the purification process. Computational analyses were conducted to gain a more profound understanding of the implications of molecular structure.

A rapid mechanical ball milling method at room temperature has been proposed for Mn2+ doping. The mechanical force generated by the ball milling process was able to hammer Mn atom into the Bi3O4Br lattice in an efficient and stable manner. Doping with Mn2+ produces a doping level in the forbidden band. Also, Mn2+ promptly scavenged the photogenerated holes, reducing the recombination of photogenerated carriers and promoting the production of numerous active species. As a result, Mn2+ doped Bi3O4Br exhibited enhanced photodegradation performance towards antibiotic tetracycline, in which the optimal efficiency arrives 81.74%, 1.22 times higher than Bi3O4Br.

Biogenic synthesis of nanomaterials represents a promising alternative to traditional chemical synthesis due to its environmentally friendly nature, cost-effectiveness, low toxicity, and high biocompatibility. The primary objective of this study was to develop a novel biogenic synthesis method for titanium dioxide (TiO2) nanoparticles using an aqueous extract of Annona muricata L. as a stabilizing and organic reducing agent. Furthermore, our aim included a comprehensive exploration of the structural, morphological, and optical properties of these nanostructures. The methodology employed in this project was grounded in the biogenic synthesis of TiO2, utilizing the aforementioned extract as a key component. We conducted a comprehensive characterization approach to unravel the formation mechanism and validate the morphology and crystalline structure of the nanomaterial. We successfully synthesized nanoparticles with spherical morphology and an average diameter of 13.41 nm, characterized by their remarkable uniformity and high-quality crystalline structure. Additionally, we assessed the applicability of these nanoparticles in photocatalysis processes aimed at the degradation of organic dyes. Our findings indicated efficient initial activity in the kinetics of methylene blue dye degradation, with a reduction of 59.25 % within the first 30 min of exposure.

Disputes about the probable availability of safe water and the efficacy of processed wastewater are key issues that necessitate a suitable solution to enhance the quality of clean water. The current research emphasizes the synthesis of ZnSe-reduced graphene oxide nanocomposites (ZnSe:rGO) with different weight ratios of rGO (represented as X = 0.6, 1 and 1.6 g)via one-step hydrothermal method. The photocatalytic performance for the degradation of methyl violet (MV) dye was investigated under visible light irradiation by varying the reaction parameters. The crystal structure, elemental composition, surface functionality and morphology of the synthesized ZnSe-XrGO nanocomposites were estimated by powder X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX), Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopic (SEM) techniques. UV–visible spectroscopy was used to investigate the optical properties. The highest efficiency is obtained for ZnSe-XrGO in 1:1 and it showed pseudo 1st order behavior with rate constant of 0.0167min−1and 94 % photodegradation of MV in just 3 h. Furthermore, hazardous effects of MV were investigated on the germination and growth of Zea mays seeds by giving them aqueous solution of MV (0, 8, 12, 24 and 48 ppm) and the decontaminated water after photodegradation of MV with the synthesized photoactive composite. The results showed profound negative effect on both germination and seedling growth at higher concentration (>12 ppm) of the dye solution. No hazardous effects were observed on both these parameters when it was given the dye degraded water which reflects the practical use of the synthesized catalyst for water remediation. The current study fulfills the goal of designing an efficient visible-light active nano-photocatalyst and its direct applicability on life sciences for water purification.

Implementing nanosized materials (1–100 nm) are considered to be effective approaches in addressing the issue of liquid waste pollution. Herein, ZnO-carbon quantum dots (ZnO-Cdots) were conducted by three-steps hydrothermal synthesis and the structural characterization is confirmed by the physical properties measurement, while, photodegradation activity of ZnO-Cdots compared to the prepared ZnO nanoflower has been investigated using UV–visible absorbance spectroscopy and its effect on organic pollutant removal from aqueous. The obtained ZnO-Cdots composites showed a superior performance in photocatalytic degradation of methylene blue (MB) and specific antibacterial activity against Staphylococcus aureus (S.A) and Eschericia coli (E.coli) compared to the prepared ZnO nanoflower. The findings of this research of ZnO-Cdots show great potential in treating liquid waste pollution, and can be considered as a promising antibacterial agent for Staphylococcus aureus (S.A) and Eschericia coli (E.coli).

Copper oxide/cuprous oxide and carbon heterostructured nanocomposites (CuO/Cu2O-C NCs) were fabricated using an agro-biomass wheatgrass extract (WGE), presenting an innovative, eco-friendly, and facile green synthetic approach. The CuO/Cu2O-C nanocomposites engineered using WGE were extensively characterized using UV–Vis, IR, XRD, DLS, XPS, SEM, TEM, BET, and TGA characterization techniques. The synthesized CuO/Cu2O-C NCs were crystalline with a monoclinic phase and an average crystallite size of 32 nm, as confirmed by XRD. Tauc plots were utilized to calculate the band gap energies (2.05 and 1.53 eV). The synthetic procedure is optimized, and the effect of plant extract in the controlled synthesis of Cu2O content in the CuO/Cu2O-C NCs was investigated. These green CuO/Cu2O-C NCs were tested for photocatalytic activity. A detailed kinetic study was conducted to degrade pathological effluent crystal violet (CV). The nanocomposite with a higher concentration of Cu2O is potentially a superior photocatalyst and demonstrated an excellent synergistic action, removing around 80 % of the crystal violet stain in visible light. Apart from photodegradation, these CuO/Cu2O-C NCs were good antioxidants and displayed good antibacterial activity against the gram-positive and gram-negative bacterial strains. The key highlight of this work is the low-cost disruptive engineering strategy for synthesizing frugal nanomaterials for multifaceted applications.

The use of dyes increased with the development of Iraq's textile industry. Synthetic dyes are still widely used because of the various benefits they provide. However, synthetic colors do not biodegrade; therefore, their release into the environment could be harmful. In this study, simple coprecipitation was used to produce multi metal ferrites (ZnxMn1-xFe2O4) as photocatalysts for the degradation of the synthetic dye Rhodamine B (Rh B). The XRD, EDX, SEM, BET, DRS, and VSM” techniques were used to analyze the produced materials. Photodegradation efficiencies were tested by varying reaction parameters such pH, catalyst dosage, H2O2 addition, dye concentration, and irradiation time. It was found that the Zn0.7Mn0.3Fe2O4 sample decomposed more rapidly under some conditions. A 99% degradation was achieved after 180 min of radiation exposure in a mixture with a pH of 3.0, a catalyst dose of 1 g/L, a Rh B concentration of 20 mg/L, and 1 mL of hydrogen peroxide. Also analyzed were processes for removing “total organic carbon” (TOC) and “chemical oxygen demand” (COD). Rh B at a concentration of 20 ppm was most effective at removing both TOC (75%) and COD (80%).

Herein, a cost-effective and nontoxic method was employed for the synthesis of g-C3N4-FeVO4 heterojunction nanocomposite photocatalyst. In this method, first g-C3N4 was synthesized from urea by chemical free thermal treatment method. Then FeVO4 nanomaterial was introduced on its surface by co-precipitation method. The prepared nanocomposite was characterized by XRD, Raman, FTIR, XPS, FESEM, and UV-DRS to determine the crystalline phase, functionality, bonding, morphology and band gap. The synthesized nanomaterial was used for the photocatalytic degradation of highly carcinogenic rhodamine B (Rh B) dye from aqueous solution using solar-light irradiation. The composite has remarkably higher photocatalytic behavior compared to pure g-C3N4 and FeVO4. Again, the degradation rate constant of Rh B for g-C3N4-FeVO4 is remarkably more compare to its parent materials. The pattern of the heterojunction formation between g-C3N4 and FeVO4 helps to separate the electron pair thereby increased the photoactivity properties of the composite. Scavenger studies were also performed in order to understand the mechanism of photodegradation. It was observed that along with the electron and hole pairs generated by light photons, hydroxide radicals play an important role in the degradation mechanism.

Cow teeth are a type of natural biomaterial exhibiting a unique hierarchical porous structure that has not been widely studied in catalysis. In this work, from a simple deposition and calcination process, a Cow Teeth composite CCT-TiO2 was fabricated using Calcined Cow Teeth as a template and employed as a biocatalyst to remove a specific target dye from an aqueous solution under UV irradiation.The composite, CCT-TiO2, with a dosage of (0.2 g/L), at room temperature and a 3 h treatment time under UV light, showed a positive behavior towards the photochemical degradation of Methylene Blue (C = 0.01 g/L) mainly in a basic medium pH = 8 giving a catalytic efficiency rate up to 98%.The main parameters affecting the efficiency of the photocatalytic treatment, such as pH, the mass of catalyst added to the solution, the percentage of TiO2 in the composite, the concentration of MB at the beginning, the presence of ethanol, the addition of hydrogen peroxide and the temperature were studied to evaluate their influence on the degradation of methylene blue.The photodegradation performance is inversely proportional to the initial dye concentration. Similarly, for the temperature, the higher the temperature, the higher the photodegradation performance (removal rate 57% for a temperature of 55 °C). However, the presence of ethanol in the solution has a negative impact on the oxidation process, with a yield of 56% after 4 h30 min of treatment under UV irradiation. On the other side, the addition of oxygenated water considerably improves the photodegradation performances of methylene blue, with an efficiency of dye removal going up to 87% after 1 h of treatment.The excellent catalytic degradation performance and low cost suggest that this process has significant potential for effectively treating industrial wastewater loaded with cationic dye.

Solar-driven water evaporation is crucial for drinkable water production using cost-effective solar energy and has recently gained more interest through the improvement of heat localization strategies. However, the original water sources may contain oil impurities and other organic pollutants that seriously impair the evaporation process and pose environmental hazards. Here, we developed a multifunctional nanocomposite Ag, Cu-rGO for the production of clean water by simultaneous photocatalysis, oil resistance, adsorption, and water evaporation powered by the sun. The phonon-assisted relaxation process under solar irradiation was effectively accelerated by the incorporation of rGO by Ag and CuNPs alloy, which can alter the bandgap and introduce a significant number of intermediate band (IB) states. We demonstrate that by employing the Ag, Cu-rGO evaporator under solar light irradiation, a high-water evaporation rate of 1.89 kg m−2 h−1 with a high solar-to-heat conversion efficiency of 90.2% can be accomplished. Additionally, the membrane can concurrently purify the raw water during solar evaporation by organic dye degradation, heavy metals adsorption, oil resistance, and pathogenic bacteria disinfection. Meanwhile, the heat dissipation to the bulk water can be recovered by the conversion to electricity using a commercial TE-module which simultaneously generates voltage generation of 17.3 mV with a power density of 5.72 W m−2. For solar-driven water evaporation from multiple sources, such an all-in-one multifunctional membrane is an excellent candidate.