Search

Cerium‐doped zinc oxide (Ce‐ZnO) nanocones with cerium concentrations of 0, 0.5, 1, and 2 % were synthesized using a sol‐gel method. Their effectiveness as photocatalysts for degrading dyes such as Rhodamine B (RhB), Methylene Orange (MO), and Methylene Violet (MV) was evaluated. The optical and structural properties, particle size distribution, and morphology of these nanocones were examined using X‐ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet‐visible (UV‐Vis) spectrophotometry. XRD results confirmed that the nanocones were highly crystalline with a hexagonal wurtzite structure, and a noticeable blue shift was observed in the Ce‐doped ZnO nanocones compared to pure ZnO. The photocatalytic performance under UV exposure showed that cerium doping significantly improved the degradation of RhB, MO, and MV. Notably, ZnO nanocones doped with 1 % cerium exhibited the highest photocatalytic efficiency, achieving 100 % degradation of RhB within 60 minutes. Additionally, 1 % Ce‐ZnO nanocones demonstrated degradation efficiencies of 86.3 % for MO and 74.9 % for MV within the same time frame. [ABSTRACT FROM AUTHOR]

In this research, Sr-doped hydroxyapatite, HAp and NiO nanoparticles were used to produce a novel nanocomposite, Sr-doped HAp/NiO. Various analytical and instrumentation techniques such as FTIR, PXRD, UV-DRS, SEM, TEM, and XPS were used to characterize the as synthesized composite material. The nanocomposite acts as an efficient photocatalyst and is able to degrade Congo red (CR) dye up to 95.6% within 40 min under solar light irradiation without any kind of external additive. The HR LC–MS spectrum was recorded to determine the degradation products of the chosen organic dye. Furthermore, the as prepared nanocatalyst also effectively reduced 98.7% of carcinogenic Cr(VI) to Cr(III) within just 10 min. In order to propose the photocatalytic mechanism and to detect the active radicals present, a radical trapping experiment was conducted. As an appealing photocatalyst for wastewater treatment and reduction of toxic chemicals, the research concluded with a methodical and cost-effective process for producing the Sr-doped HAp/NiO nanocomposite. [ABSTRACT FROM AUTHOR]

[Display omitted] • Nanosized ZnGa 2 O 4 :Cu was designed for continuously degrading pollutants. • The doping of Cu(II) highly increased the persistent production and availability of active species. • •H radicals were identified as the main active species. • A possible mechanism for the persistent degradation of dyes was proposed. Photocatalysis is considered as an environmentally friendly and sustainable method as it can produce active species to degrade pollutants. However, its applications are hindered by the turbidity of pollutants and the requirements for continuous or repeated in situ irradiation. To avoid the need for continuous in situ irradiation in the photocatalytic process, herein we report the doping of Cu(II) ions into zinc gallate (ZnGa 2 O 4) as traps to capture photo-generated electrons. In this way, long lifetime charge release and separation were effectively achieved for the persistent degradation of organic dyes in wastewater. The Cu(II) doped ZnGa 2 O 4 (ZGC) nanoparticles with a small size about 7.7 nm synthesized via a hydrothermal method exhibited a persistent photocatalytic activity with continuous production of reactive oxygen species for at least 96 h without in situ irradiation due to its unique electronic structure and carrier transport path, and enabled to degrade 82.2 % of rhodamine B in 1 h. Further investigation revealed that the doped Cu(II) ions occupied the octahedral sites of ZGC and highly increased the persistent production and availability of active species for the persistent degradation of organic dyes under pre-illuminated conditions. [ABSTRACT FROM AUTHOR]

The total annual contribution of textile, material, and other industrial effluents is large in numbers and discharges into water bodies that are not biodegradable. Hence, there is a need for the disposal of dyestuff water effluents with financially savvy innovation. In this regard, photocatalytic degradation of Azure-A is considered a highly significant and acceptable procedure for organic dye decomposition. In the past few years, metal iodide has also received much attention due to its great decomposition efficiency as a photocatalyst to decompose different organic dyes. The present work investigates the comparative photocatalytic competence of synthesized metal bismuth iodides (MBI). The various operational parameters, such as the effect of the Azure-A concentration, the amount of photocatalyst, the pH of the experimental solution, and the intensity of light, were studied. The maximum degradation values for cobalt bismuth iodide were obtained. Photocatalysts were static and maintained significant degradation efficiency, ensuring their reusability. [ABSTRACT FROM AUTHOR]

The presented study was focused on the simple, eco-friendly synthesis of composite hydrogels of crosslinked carboxymethyl cellulose (CMC)/alginate (SA) with encapsulated g-C3N4 nanoparticles. The structural, textural, morphological, optical, and mechanical properties were determined using different methods. The encapsulation of g-C3N4 into CMC/SA copolymer resulted in the formation of composite hydrogels with a coherent structure, enhanced porosity, excellent photostability, and good adhesion. The ability of composite hydrogels to eliminate structurally different dyes with the same or opposite charge properties (cationic Methylene Blue and anionic Orange G and Remazol Brilliant Blue R) in both single- and binary-dye systems was examined through adsorption and photocatalytic reactions. The interactions between the dyes and g-C3N4 and the negatively charged CMC/SA copolymers had a notable influence on both the adsorption capacity and photodegradation efficiency of the prepared composites. Scavenger studies and leaching tests were conducted to gain insights into the primary reactive species and to assess the stability and long-term performance of the g-C3N4/CMC/SA beads. The commendable photocatalytic activity and excellent recyclability, coupled with the elimination of costly catalyst separation requirements, render the g-C3N4/CMC/SA composite hydrogels cost-effective and environmentally friendly materials, and strongly support their selection for tackling environmental pollution issues. [ABSTRACT FROM AUTHOR]

Iron oxide nanoparticles were synthesized by co-precipitation using three different iron salt stoichiometric mole ratios. Powder X-ray diffraction patterns revealed the inverse cubic spinel structure of magnetite iron oxide. Transmission electron microscopic images showed Fe3O4 nanoparticles with different shapes and average particle sizes of 5.48 nm for Fe3O4-1:2, 6.02 nm for Fe3O4-1.5:2, and 6.98 nm for Fe3O4-2:3 with an energy bandgap of 3.27 to 3.53 eV. The as-prepared Fe3O4 nanoparticles were used as photocatalysts to degrade brilliant green (BG), rhodamine B (RhB), indigo carmine (IC), and methyl red (MR) under visible light irradiation. The photocatalytic degradation efficiency of 80.4% was obtained from Fe3O4-1:2 for brilliant green, 61.5% from Fe3O4-1.5:2 for rhodamine B, and 77.9% and 73.9% from Fe3O4-2:3 for both indigo carmine and methyl red. This indicates that Fe3O4-2:3 is more efficient in the degradation of more than one dye. This study shows that brilliant green degrades most effectively at pH 9, rhodamine B degrades best at pH 6.5, and indigo carmine and methyl red degrade most efficiently at pH 3. Recyclability experiments showed that the Fe3O4 photocatalysts can be recycled four times and are photostable. [ABSTRACT FROM AUTHOR]

Semiconductor photocatalysts are promising for Oxygen evolution reaction (OER) and also for reducing organic pollutants in wastewater. However, their limited activity under UV light and the fast recombination of electron-hole pairs, hinder their utilization in wastewater treatment. To address these challenges a novel photocatalyst based on carbon quantum dots (CQDs) supported Zinc–Cobalt Oxide (ZnCo 2 O 4) was developed, which demonstrated enhanced photocatalytic efficiency. Experimental findings indicated that 0.7 CQDs/ZnCo 2 O 4 exhibited superior photocatalytic performance compared to ZnCO 2 O 4 and CQDs/ZnCO 2 O 4 composites materials, achieving over 100 and 96 % decomposition of methylene blue (MB) and methylene orange (MO) dyes after 50 and 140 min under UV light. The enhanced performance of 0.7 CQDs/ZnCo 2 O 4 can be attributed to the charge transfer rate and synergistic effect between the coupled CQDs and ZnCo 2 O 4. Moreover, studies with radical scavengers reveal that •O 2 , •OH, and h+ play crucial roles in the breakdown of MB and MO dyes. Furthermore, 0.7 CQDs/ZnCo 2 O 4 displayed very low overpotential of 220 mV at 100 mA cm−2 for OER activity with a robust durability for 250 h at 500 mA cm−2. • CQDs-decorated ZnCo 2 O 4 Mss was developed by facile impregnation-thermal methode. • The enhanced catalytic activity of CQDs/ZnCo 2O 4 is due to the n-p junction, which generatesholes, ●OH, and ●O 2−. • Optimized 0.70 CQDs/ZnCo 2O 4 achieves nearly100% MB degradation in 50 min. • The photocatalytic degradation mechanism of CQDs/ZnCo 2O 4 MSs enhanced charge separation and improve overall photocatalytic activity. [ABSTRACT FROM AUTHOR]

Photocatalysis, mainly using TiO2 as a catalyst, has emerged as a promising method to address the issue of wastewater treatment. This study explores the enhanced photocatalytic activity of TiO2 through the introduction of reduced graphene oxide (rGO) and cadmium sulfide (CdS) as selective metal dopants. The incorporation of rGO and CdS into the TiO2 lattice aims to optimize its photocatalytic properties, including bandgap engineering, charge carrier separation, and surface reactivity. The unique combination of CdS and rGO with TiO2 is expected to boost degradation efficiency and reduce the reliance on expensive and potentially harmful sensitizers. This experimental investigation involves the synthesis and characterization of TiO2-based photocatalysts. The photocatalytic degradation of methyl orange (MO) and methylene blue (MB) was assessed under controlled laboratory conditions, studying the influence of metal dopants on degradation kinetics and degradation efficiency. Furthermore, the synthesized photocatalyst is characterized by advanced techniques, including BET, SEM, TEM, XRD, and XPS analyses. The degraded samples were analyzed by UV-Vis spectroscopy. Insights into the photoexcitation and charge transfer processes shed light on the role of metal dopants in enhancing photocatalytic performance. The results demonstrate the potential of a TiO2-rGO-CdS-based photocatalyst in which 100% degradation was achieved within four hours for MO and six hours for MB, confirming efficient azo dye degradation. The findings contribute to understanding the fundamental principles underlying the photocatalytic process and provide valuable guidance for designing and optimizing advanced photocatalytic systems. Ultimately, this research contributes to the development of sustainable and effective technologies for removing azo dyes from various wastewaters, promoting environmental preservation and human well-being. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) materials have recently drawn interest in various applications due to their superior electronic properties, high specific surface area, and surface activity. However, studies on the catalytic properties of the 2D counterpart of V2O5 are scarce. In the present study, the catalytic properties of 2D V2O5 vis-à-vis bulk V2O5 for the degradation of methylene blue dye are discussed for the first time. The 2D V2O5 catalyst was synthesized using a modified chemical exfoliation technique. A massive increase in the electrochemically active surface area of 2D V2O5 by one order of magnitude greater than that of bulk V2O5 was observed in this study. Simultaneously, ~ 7 times increase in the optical absorption coefficient of 2D V2O5 significantly increases the number of photogenerated electrons involved in the catalytic performance. In addition, the surface activity of the 2D V2O5 catalyst is enhanced by generating surface oxygen vacancy defects. In the current study, we have achieved ~ 99% degradation of 16 ppm dye using the 2D V2O5 nanosheet catalysts under UV light exposure with a remarkable degradation rate constant of 2.31 min−1, which is an increase of the order of 102 from previous studies using V2O5 nanostructures and nanocomposites as catalysts. Since the enhanced photocatalytic activity emerged from the surface and optical properties of the catalyst, the current study shows great promise for the future application of 2D V2O5 in photo- and electrocatalysis. [ABSTRACT FROM AUTHOR]

Developing a low-cost and highly efficient semiconductor photocatalyst for the decomposition of organic pollutants and antibiotics is highly desirable. Herein, FeOOH nanosheets were prepared using a liquid-phase stirring technique and combined with ZnCdS (ZCS) nanoparticles to construct FeOOH/ZCS nanocomposite photocatalysts. The photocatalytic efficiency of the FeOOH/ZCS nanocomposite was evaluated for the decomposition of various pollutants, including rhodamine B, methylene Blue, and tetracycline. The FeOOH/ZCS nanocomposite exhibited significantly higher photocatalytic performance for the decomposition of various organics. Moreover, the optimized FeOOH/ZCS retained more than 90% of its initial photocatalytic activity even after five successful runs. Radical quenching test and electron spin resonance (ESR) analysis revealed that hydroxyl radicals (•OH) play a dominant role for the decomposition of organics. The FeOOH/ZCS Z-scheme heterojunction significantly facilitates higher charge transfer efficiency and the generation of reactive radicals, resulting in excellent photocatalytic degradation performance. This work offers a new approach to synthesis FeOOH-based photocatalyst for the elimination of organics and antibiotics in water. [ABSTRACT FROM AUTHOR]

Herein, a Bi2S3/Cu2S was successfully synthesized via a simple one-step wet impregnation process. The compositional behavior and electrical and optical properties of photocatalysts were investigated in detail. Photocatalytic technology has shown great promise in wastewater treatment, splitting water to hydrogen, and converting CO2 to fuel. Researchers or scientist are attempting to design sulfate-based heterojunction photocatalytic systems in order to develop novel photocatalysts with excellent performance. Photodegradation of methylene blue (MB) dye and tetracycline (TC) drug under visible light irradiation was used to assess the photocatalytic activity of as-prepared samples. As a result, 2:1% wt of Bi2S3/Cu2S heterostructure composite revealed superior visible light degradation performing of MB dye, and TC drug efficiency as 90.2% and 87.5%, respectively. The prepared hybrid photocatalyst has demonstated a potential for use in the photocatalytic degradation of antibiotic durgs and dyes, indicating a promissing future for its application. [ABSTRACT FROM AUTHOR]

Rapid industrialization and ever-growing human activities have caused more and more serious water pollution in the last few decades, posing great threats towards both human health and ecological environment. Organic dyes, as one of the major water pollutants, are usually toxic, chemically stable, and hard to degrade. In this paper, a novel PCN-222(Zn)/GO composite was obtained by combining porphyrin-based metal organic framework material PCN-222(Zn) with graphene oxide (GO). The structure and morphology of the composite were characterized by FTIR, XRD, SEM, and optical microscopy. The thermal stability and optical properties were studied by thermogravimetric analysis (TGA) and fluorescence spectroscopy. PCN-222(Zn) and PCN-222(Zn)/GO were used as both adsorbents and photocatalysts for the adsorption and visible light photodegradation of organic dye methylene blue in aqueous solutions. It is found that the blending of GO can improve the photocatalytic degradation activity of PCN-222(Zn) towards organic dyes. [ABSTRACT FROM AUTHOR]

The release of industrial effluents into fresh water is a major contributor of water contamination. Therefore, it is highly desirable to develop a viable solution to this alarming issue to improve the quality of clean water. To enhance the photocatalytic efficiency and hence utilization ratio of CuO, a series of CuO–FeSe2 composites with different varying contents of FeSe2 were prepared through facile synthetic methods. X-ray diffraction (XRD) and energy-dispersive X-rays (EDX) analysis verified that the samples were successfully prepared without any contaminating phases. The average crystallite sizes of CuO and FeSe2 were computed to be 29 and 21 nm respectively. For the CuO–FeSe2 composites, the crystallite sizes varied between 25 and 27 nm. The morphology of CuO was comprised of needle-shaped structures, whereas that of FeSe2 was observed to be flower-shaped structures comprising of irregular crystals. A red shift in the bandgap of CuO–FeSe2 composites was observed with the increase in FeSe2 concentration. The prepared photocatalysts were utilized to evaluate their efficiency under visible light against Rhodamine B (RhB). Among all the prepared composites, CuO–75% FeSe2 revealed a remarkable performance and degraded 96% RhB in 180 min. Rate constants for the degradation of the dye were determined by applying the Langmuir–Hinshelwood model. [ABSTRACT FROM AUTHOR]

Magnetic separation of photocatalysts holds great promise for water treatment. A magnetic separation method has a positive effect on the recovery of catalysts after degradation. In this paper, an efficient and reusable catalytic system is developed based on coating magnetic Fe3O4 by depositing Fe2+ on the surface of ZnO. The Fe3O4/ZnO nanocomposite exhibits enhanced performance for organic pollutant degradation. The Fe3O4/ZnO system demonstrates a high photocatalytic activity of 100% degradation efficiency in Rhodamine B (RhB) degradation under UV light irradiation for 50 min. The excellent photocatalytic activity is primarily due to the separation of photogenerated electron-hole pairs being facilitated by the strong interaction between Fe3O4 and ZnO. The induction of the magnetic Fe3O4 endows the Fe3O4/ZnO composite with superior magnetic separation capability from water. Experiments with different radical scavengers revealed that the hydroxyl radical (·OH) is the key reactive radical for the effective degradation of RhB. This work innovatively affords a common interfacial dopant deposition strategy for catalytic application in the degradation of organic dye pollutants and catalyst separation from wastewater efficiently. [ABSTRACT FROM AUTHOR]

Advanced oxidation processes, including photocatalysis, have been proven effective at organic dye degradation. Tailored porous materials with regulated pore size, shape, and morphology offer a sustainable solution to the water pollution problem by acting as support materials to grafted photocatalytic nanoparticles (NPs). This research investigated the influence of pore and particle sizes of photocatalytic MICROSCAFS® on the degradation of methyl orange (MO) in aqueous solution (10 mg/L). Photocatalytic MICROSCAFS® are made of binder-less supported P25 TiO2 NPs within MICROSCAFS®, which are silica–titania microspheres with a controlled size and interconnected macroporosity, synthesized by an adapted sol–gel method that involves a polymerization-induced phase separation process. Photocatalytic experiments were performed both in batch and flow reactors, with this latter one targeting a proof of concept for continuous transformation processes and real-life conditions. Photocatalytic degradation of 87% in 2 h (batch) was achieved, using a calibrated solar light simulator (1 sun) and a photocatalyst/pollutant mass ratio of 23. This study introduces a novel flow kinetic model which provides the modeling and simulation of the photocatalytic MICROSCAFS® performance. A scavenger study was performed, enabling an in-depth mechanistic understanding. Finally, the transformation products resulting from the MO photocatalytic degradation were elucidated by high-resolution mass spectrometry experiments and subjected to an in silico toxicity assessment. [ABSTRACT FROM AUTHOR]

Organic dye pollutants are the most common type of pollutant found in water and wastewater as a result of various industrial activities. In particular, one of the largest contributors is the textile industry, which uses a lot of organic dyes to produce its goods. Organic dyes that remain in the effluents are typically permanent and difficult to detoxify using traditional wastewater treatment strategies. Photocatalysis using semiconductors have emerged as an attractive wastewater treatment method for resolving the major drawbacks of traditional methods. Montmorillonite has been presented as a conceivable dye adsorbent. When a semiconductor is incorporated, its adsorptive capability assists in imposing heterogeneous photoactivity. It is widely employed in a variety of applications due to fundamental characteristics such as high flexibility, swelling, ion exchange ability, acidity, usage in catalytic amounts, milder reaction conditions, benefit in reusability, selectivity, high yield, cheap cost, and so on. In this review, we specifically describe the last 3 years' development of dye degradation employing recently developed montmorillonite (MMT)‐based materials, as well as their preparation methods. In addition, the photocatalytic degradation of various types of organic dye pollutants, such as anionic and cationic dyes, was also studied in this review. The findings reveal that MMT‐based materials have a wide range of applications in the photocatalytic degradation of contaminants existing in the environment. [ABSTRACT FROM AUTHOR]

Herein, we have designed polyfunctional materials of d10‐configuration Cd (II) "Cd‐CP." The coordination polymer Cd‐CP was synthesized using benzene‐1,4‐dicarboxylic acid and 3,5‐diaminotriazole via solvothermal reaction. The Cd‐CP has been fully characterized by using single X‐ray crystallography, thermogravimetric analysis (TGA), Fourier transform–infrared (FT‐IR) spectroscopy, Raman spectroscopy, scanning electron microscopy (SEM), powder X‐ray diffraction (PXRD), and Brunauer–Emmett–Teller (BET) analysis. Single crystal X‐ray crystallography revealed that the CP‐Cd crystallized in triclinic space group P – 1 with the chemical composition [(BDC)(DAT)2Cd2Cl] (CH3)2 NH2+ · H2O. The present study investigated the impact of different reaction parameters, including the concentration of MG, the dosage of catalyst, and the duration of irradiation, on the outcome demonstrating a high level of photocatalytic efficacy at 99.19% under visible light irradiation. The obtained kinetic data exhibited conformity with a pseudo‐first‐order model, indicating that the rate‐determining step is likely to be photo‐absorption. The value of the apparent rate constant was found to be 0.019 min−1 for 50 mg L−1, 0.016 min−1 for 100 mg L−1, and 0.015 min−1 for 150 mg L−1 MG concentration. The corresponding half‐life time was found to be 36.44, 43.31, and 46.20 min with values of correlation coefficient (R2) as 0.99, 0.93, and 0.98, respectively. Moreover, a trapping experiment was conducted to demonstrate that hydroxy radicals (•OH) are the principal reactive oxygen species (ROS) responsible for the degradation of MG. The results of the total organic carbon (TOC) study indicated a mineralization value of around 89%, suggesting that the dye has been completely degraded into non‐toxic by‐products such as carbon dioxide (CO2) and water (H2O). [ABSTRACT FROM AUTHOR]

Water, essential for all life, faces contamination challenges due to industrialization and unchecked urban development, producing pollutants such as organic dyes, detergents, heavy metals, and pesticides. This has emerged as one of the most pressing environmental concerns in recent years, with a particular emphasis on organic dyes due to their demonstrated health-related concerns. In this context, this paper reviews the use of photocatalysis as a wastewater treatment method, highlighting its significant potential for removing organic dyes from aqueous solutions. Additionally, the focus is on the design, development, performance enhancement, and overall research progress in fabricating graphene-based semiconductor nanocomposites as photocatalysts. Representative examples are discussed, emphasizing the potential of these nanocomposites in degrading toxic organic dyes through photocatalysis. The enhanced photoactivity is attributed to the synergistic effects of graphene and semiconductor materials, leading to improved light absorption, charge separation, and reactive oxygen species generation. This comprehensive review provides valuable insights to advance wastewater treatment technologies and address environmental impacts caused by organic dye pollution. [ABSTRACT FROM AUTHOR]

In this paper, three-dimensional TiO2 nanoflowers (NFs) were prepared by a facile hydrothermal method, and Ag3PO4 was grown in situ following alkali treatment to design and synthesize a Ag3PO4/OH/TiO2 catalyst with excellent photocatalytic activity under visible light. The test results show that the photocatalytic degradation performance of TiO2 NFs after alkali treatment and Ag3PO4 loading is significantly improved. This is because the alkali treatment and the introduction of Ag3PO4 can provide a large amount of –OH, which can be converted to ˙OH under UV irradiation, followed by an increase in the number of active radicals to enhance the photocatalytic degradation performance. Meanwhile, the introduction of Ag3PO4 can effectively improve the light absorption ability of the photocatalyst. Moreover, the in situ growth of Ag3PO4 on TiO2 NFs can construct a high-quality Ag3PO4/TiO2 heterojunction to promote the charge separation and transport. Therefore, the degradation rate of Ag3PO4/OH/TiO2 can reach 90% after 30 min for degrading 3 mg L−1 RhB under visible light. The Ag3PO4/OH/TiO2 photocatalyst designed in the present work provides a new tool for the degradation of organic dyes. [ABSTRACT FROM AUTHOR]

In the current research, new metal complexes have been synthesized by using the greener synthetic approach in which 3‐Nitroaniline reacts with the elements of group‐IIB and group‐IVB. According to this method, ligand and metals were dissolved in 1,4‐dioxane and stirred at room temperature for a specific time period. The method for the preparation of metal‐base complexes is quite simple and cost‐effective. To identify the synthesized compounds various physio‐chemical analytical techniques were used such as Melting point, FT‐Raman Spectroscopy, FT‐IR Spectroscopy, Thermogravimetric analysis, and Scanning electron microscope (SEM) that provide significant data about the general structural characteristics of synthesized compounds. The percentage degradation efficiency of synthetic dyes was obtained as 57 %, 66 %, and 97 % using the synthesized compounds as photocatalysts. A statistical tool, RSM was used for the optimization of parameters (Concentration of Dye, Dose of Catalyst, and contact time). [ABSTRACT FROM AUTHOR]

Toxic organic dyes-containing wastewater treatment by adsorption and photocatalytic techniques is widely applied, but adsorbents and photocatalysts are often synthesized through chemical methods, leading to secondary pollution by released chemicals. Here, we report a benign method using Tecoma stans floral extract to produce MgFe2O4/ZnO (MGFOZ) nanoparticles for adsorption and photocatalytic degradation of coomassie brilliant blue (CBB) dye. Green MGFOZ owned a surface area of 9.65 m2/g and an average grain size of 54 nm. This bio-based nanomaterial showed higher removal percentage and better recyclability (up to five cycles) than green MgFe2O4 and ZnO nanoparticles. CBB adsorption by MGFOZ was examined by kinetic and isotherm models with better fittings of Bangham and Langmuir or Temkin. RSM-based optimization was conducted to reach an actual adsorption capacity of 147.68 mg/g. Moreover, MGFOZ/visible light system showed a degradation efficiency of 89% CBB dye after 120 min. CBB adsorption can be controlled by both physisorption and chemisorption while •O2- and •OH radicals are responsible for photo-degradation of CBB dye. This study suggested that MGFOZ can be a promising adsorbent and catalyst for removal of organic dyes in water. [ABSTRACT FROM AUTHOR]

Industrial wastewater has detrimental impacts on aquatic ecosystems and the environment. Among the significant contributors to water pollution are organic dyes, which are frequently released into untreated outflow water. Hence, effective degradation of these dyes and their derivatives using heterogeneous photocatalysts is imperative before discharge. In this study, we successfully synthesized a novel nanocomposite by g-C3N4 coupled with TiO2 and decorated it with Ni followed by cost-effective methods. Immaculate g-C3N4 coupled with TiO2 (TiO2+) and modified with nickel (Ni+) was synthesized through melamine calcination followed by hydrothermal processing. Characterization through diverse electro-analytical techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FT-IR), and Brunauer-Emmett-Teller (BET), was conducted on the novel photocatalysts. XRD results revealed their high crystallinity, enhanced through modification. The effectiveness of these photocatalysts in degrading the organic dye methylene blue (MB) under UV–Vis light was thoroughly investigated. It also investigated how the results were affected by important factors involving contact time, dye and photocatalyst dosages, pH, and reusability. Among the photocatalysts, the composite g-C3N4-TiO2s, decorated with Ni, exhibited exceptional performance, displaying substantial degradation efficacy. The findings demonstrate that the novel g-C3N4-based photocatalysts are highly efficient at degrading organic dyes, so the work is expected to be the best contribution in the photodegradation study of organic contaminants. [ABSTRACT FROM AUTHOR]

Developing novel eco-friendly broad-spectrum visible light photocatalysts for dye removal is one of the urgent problems for water treatment. Here, copper-doped carbon dots (CDs) were reported to be directly fabricated from chromated copper arsenate (CCA) wood waste for the photocatalytic degradation of the methylene blue dye. The properties of the resulting CDs were thoroughly characterized and analyzed, preceding an investigation into the adsorption kinetics of dye degradation. The kinetic study showed that reactant concentration was the rate-limiting factor. The obtained CDs showed a 151 mg/g photocatalytic degradation capacity. Comparing pure CDs to CDs/TiO2 composites, the former demonstrated higher photodegradation efficiency. This superiority can be attributed to the synergistic action of adsorption and photocatalytic degradation working in tandem. This study prepared Cu doped CDs and elucidated the photocatalysis mechanism of methylene blue degradation by CDs. The photodegradation of organic dyes through CDs derived from waste CCA wood emerges as an eco-friendly, facile, and highly efficient method. [ABSTRACT FROM AUTHOR]

In this study, a series of AgCl/ZnO-loaded nanofibrous membranes were prepared using coaxial electrospinning. Their physical and chemical characteristics were evaluated by SEM, TEM, XRD, XPS, IR, PL, and UV–visible spectrometer, and the photocatalytic experiments using methylene blue (MB) as a model pollutant. The formation of AgCl/ZnO heterojunction and the structure of core–shell nanofibers with porous shell layer were confirmed. AgCl/ZnO photocatalysts were also effectively loaded onto the surfaces of the porous core–shell nanofibers. The results of photocatalytic experiments revealed that the AgCl/ZnO (MAgCl:MZnO = 5:5)-loaded nanofibrous membrane achieved a degradation efficiency of 98% in just 70 min and maintained a photocatalytic efficiency exceeding 95% over the first five experimental cycles, which successfully addressed the issues of photocatalytic efficiency loss during the photodegradation of MB with AgCl/ZnO nanoparticles as photocatalyst. The photodegradation mechanism was also researched and proposed. [ABSTRACT FROM AUTHOR]

Impregnation of nano‐metal oxides can provide functional properties to textiles, like UV protection and self‐cleaning properties. These properties are quite important as they can provide protection against UV damage, help to reduce cleaning efforts, improve the ease of maintenance, and help to protect the water resources. The usage of nanoparticles improves multifunctional effects due to their high surface area. Therefore, in this study, nano‐sized TiO2 and ZnO were applied to cotton fabrics as single type or hybrids with different concentrations to reveal their effects on multifunctional properties (UV‐protection, self‐cleaning, wettability, photocatalytic activity). Also, the weight and air permeability of samples were determined to evaluate their usability. Scanning electron microscopy, x‐ray diffraction and Fourier transform infrared spectroscopy were also utilized to analyze the samples. According to the results, some samples exhibited good–very good UV protection. Up to 78.5% photocatalytic degradation of organic dye was achieved by nano‐TiO2 application. According to self‐cleaning test results, nano‐TiO2 applied samples showed yellowing after UV irradiation. Hybrid‐coated samples were more advantageous regarding self‐cleaning, especially against cherry juice stains. The staining and wettability results of the samples were in accordance. Weight and air permeability changes were acceptable to maintain the usage of the samples for clothing and other applications. [ABSTRACT FROM AUTHOR]

In this work, a composite ZnO/MoS2/AuNPs supported on carbon fiber cloth (CFC) was prepared by progressively growing ZnO nanorods array, MoS2 nanosheets and AuNPs on CFC for sensitive SERS detection and efficient photocatalytic degradation of organic dye pollutants. The ZnO/MoS2 heterojunctions showed a significant CM effect and further decorating AuNPs with EM effect improved the detection limit of crystal violet (CV) from 10–6 to 10–13 M. The composite can be used for qualitative SERS detection of CV or Nile blue in standard solution or real samples with high stability and good stability. The enhancement mechanisms of CFC/ZnO/MoS2 and CFC/ZnO/MoS2/AuNPs were discussed based on corresponding characterizations and calculations. The composite also showed efficient photocatalysis for dye degradation. The ZnO/MoS2 heterojunction played a key role in enhancing the charge separation rate and improving the photocatalytic performance. The materials achieved degradation efficiencies of 71.4% for CV (1.5 × 10–5 M) after 60 min irradiation under visible light. The active radical species were investigated and possible degradation approach were proposed. Such composite with both SERS enhancement and visible light photodegradation ability has great promise in environment monitoring and remediation. [ABSTRACT FROM AUTHOR]

Functionalized conjugated microporous polymers (CMPs) containing amino, imino, and hydrazine groups are synthesized by the Sonogashira–Hagihara coupling reaction. Notably, the porosities, thermal stabilities, and morphologies of the CMPs can be controlled by the introduction of functional groups. Here, the relationships between the functional groups and photocatalytic performance are discussed for the first time. The CMP nanowires exhibit excellent photocatalytic performance in organic pollutant degradation: the degradation rate obtained by CMP-I3 bearing naphthalene groups via an imine bond is > 99.99%, and ~ 99.71% of the degradation activity is maintained after five cycles. Notably, the excellent photocatalytic properties of CMP-I3 are imparted by the introduction of the naphthalene groups, which reduced the band gap. The improved charge-transfer activity accounts for the highest and lowest photocurrent intensity and resistance achieved, respectively. Furthermore, the photocatalytic mechanism of CMPs reveals that the superoxide anion is the main active substance in the photocatalytic degradation of dyes. [ABSTRACT FROM AUTHOR]

Photocatalysis using semiconductor metal oxide stands out as a highly effective and efficient method for eliminating organic pollutants from wastewater. This study aims to assess the photocatalytic capabilities of Mn doped ZnO nanocomposites in degrading methylene blue (MB) dye under ultra-violet light exposure. This study details the synthesis of ZnO photocatalysts through a straightforward one-step sol-gel method, incorporating varying levels of Mn-doping (0%, 2% & 4%). The structural and optical attributes were examined using techniques such as powder X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), energy dispersive spectroscopy (EDS) and UV-Vis diffuse reflectance spectra. X-ray diffraction analyses verified the presence of a hexagonal wurtzite crystal structure in all synthesized samples, exhibiting a high degree of crystallinity. In addition, an investigation into the impact of Mn impurities on the photocatalytic performance of ZnO catalysts was conducted in the context of methylene blue (MB) degradation. The experimental findings revealed that the Mn doped ZnO nanoparticles produced exhibited significantly superior photocatalytic performance compared to pure ZnO when used in breaking down methylene blue under UV-light exposure. This study proposes that these Mn doped ZnO could serve as a highly effective photocatalyst for treating water contaminated with certain chemically persistent synthetic organic dyes. The improved photocatalytic capabilities of ZnO nanostructures doped with Mn were ascribed to the synergistic impact of increased surface area in ZnO nanosphere and enhanced efficiency in charge separation resulting from optimized Mn doping. A potential explanation for the heightened photocatalytic performance of Mn-doped ZnO nanostructures is proposed tentatively. [ABSTRACT FROM AUTHOR]

BACKGROUND: Preparing catalysts with heterojunction structures is a strategy to achieve efficient charge separation and transfer of charges to enhance photocatalytic activity of photocatalysts. To optimize the graphitic carbon nitride (g‐C3N4)‐based photocatalysts, Bi2MoO6@ 2D g‐C3N4 catalyst was prepared. RESULTS: 2D Bi2MoO6 nanopiece@2D g‐C3N4 nanoflake composites in different proportions were prepared by the hydrothermal method. The prepared materials were characterized by various modern instrumental analyses, and their photocatalytic ability to decompose water and degrade rhodamine B under visible light irradiation was tested. Compared with pure Bi2MoO6 nanopiece and g‐C3N4 nanoflake, the hydrogen evolution rate of Bi2MoO6 nanopiece@g‐C3N4 nanoflake (1:10) composite was highest, at 4847 μmol h−1 g−1. The composite (3:10) exhibited significantly enhanced photocatalytic rhodamine B degradation for organic dye removal due to the formation of an excellent heterojunction to improve the separation and migration efficiency of photogenerated carriers. CONCLUSION: O2− and •OH were the two main active species in the photocatalytic degradation of rhodamine B. Bi2MoO6 formed a heterojunction with g‐C3N4, which accelerated separation and migration efficiency, thereby enhancing the photocatalytic activity. © 2023 Society of Chemical Industry (SCI). [ABSTRACT FROM AUTHOR]

Environmental contamination is a major global concern. Organic dyes pose a significant threat as water pollutants, leading to the depletion of natural resources. Molybdenum disulfide (MoS2), a type of two-dimensional transition metal dichalcogenide, has gained considerable attention due to its impressive properties, such as stability, surface area, and tunable interlayer spacing. It has emerged as a promising material for both photocatalytic degradation and adsorption of harmful organic dyes. This article provides an overview of recent advancements in MoS2-based nanomaterials for the removal of organic dyes from solutions through adsorption and photocatalytic processes. The review delves into the fundamental properties of MoS2, explores various synthesis methods, and various modifications of the material to enhance its dye removal efficiency, and addresses potential challenges associated with its application in this field. Furthermore, the article discusses the prospects for improving MoS2-based materials for enhanced adsorption and photocatalytic degradation of organic dyes. [ABSTRACT FROM AUTHOR]

Synthetic organic dyes are coloring agents used in various industries. Despite the fact that they offer exciting colors and long-lasting effects, certain organic dyes can have harmful impacts on human health and aquatic ecosystems. This study investigates the photocatalytic degradation of malachite green dye using Ni–TiO2 nanoparticles (NPs) and Ni–TiO2/PANI nanocomposites (NCs) in various reaction conditions. The surface and compositional change of synthesized photocatalysts were characterized by XRD, FTIR, AAS, and UV–vis spectrophotometer. Accordingly, the XRD results signify the crystal structure of photocatalysts found to be tetragonal anatase phase while the FT-IR spectra indicate the titanium has predominantly form a coordination compound upon reaction with nitrogen atom through weakening the bond strength between C═N, C═C, and C─N in the PANI. The UV–vis measurement shows that the energy bandgaps were decreased from 3.20 to 2.77 eV and 2.59 eV for Ni–TiO2 NPs and Ni–TiO2/PANI NCs, respectively. From AAS data, the authors confirmed that Ni metal has significantly existed in the aforementioned photocatalysts after the calcination process. The photocatalytic degradation of Ni–TiO2 NPs and Ni–TiO2/PANI NCs on the model dye has studied and their efficiency was 94.22% and 99.09%, respectively. The photocatalytic degradation follows pseudo-first order with 2.23 × 10−2 min−1 reaction rate at optimum conditions of pH 8.5, initial dye concentration of 0.2 g/L, catalyst load of 0.2 g/L, and irradiation time of 90 min. With this, the outstanding result recorded using Ni–TiO2/PANI NCs is ascribed to the smaller particle size as compared to Ni–TiO2 NPs, and it is found to be the promising photocatalyst for the removal of wastewater containing organic dyes. [ABSTRACT FROM AUTHOR]

Water contamination with synthetic dyes is an escalating problem worldwide. Herein, Co3O4-decorated reduced graphene oxide (Co3O4-rGO) is reported as an effective heterogeneous photocatalyst for the decomposition of organic dyes. The synthesis of Co3O4-rGO was confirmed via spectroscopic techniques including XRD, XPS, TEM, and FTIR. After characterization, the prepared Co3O4-rGO composite was tested as a photocatalyst for the degradation of methylene blue and methyl orange. The photocatalytic efficiency of Co3O4-rGO was >95% after 60 min, corresponding to 200 mg/L as the initial concentration of each dye. The photodegradation of MB and MO was confirmed by BOD and COD measurements. Experimental parameters like the re-usability of Co3O4-rGO, the effect of catalyst dosage, and the effect of dye concentration on photocatalytic activity were also investigated. The photocatalytic activity of Co3O4-rGO for the degradation of MB was 2.13 and 3.43 times higher than that of Co3O4 and rGO, respectively. Similarly, the photocatalytic activity of Co3O4-rGO for the degradation of MO was 2.36 and 3.56 times higher than that of Co3O4 and rGO, respectively. Hence, Co3O4-rGO was found to be an efficient and reusable photocatalyst for the decomposition of selected dyes in the aqueous medium. [ABSTRACT FROM AUTHOR]

Herein we synthesized biochar/iron oxide composite (C/α‐Fe2O3/γ‐Fe2O3) by two‐step calcination method. The prepared C/α‐Fe2O3/γ‐Fe2O3 had a highly pure and a concentration ratio of α‐Fe2O3 and γ‐Fe2O3 about 1 : 1. The optical properties of as‐synthesized C/α‐Fe2O3/γ‐Fe2O3 show a lower bandgap energy (1.90 eV) than that of pure C/α‐Fe2O3 (2.02 eV). The effects of different biochar composite catalysts on the removal of amino black were investigated. Upon illumination, the total removal rate of amino black dye by C/α‐Fe2O3/γ‐Fe2O3 catalyst reached 98 %, which was about 1.7 times that of C/α‐Fe2O3. In addition, the coercivity and the remanence intensity of C/α‐Fe2O3/γ‐Fe2O3 is respectively 1.81 times and 7.17 times that of C/α‐Fe2O3. The catalyst could be magnetically separated and reused for five times with a slight loss of its reactivity. The study of biochar composite provides a new direction for the removal of toxic organic dye in wastewater. [ABSTRACT FROM AUTHOR]

Metal–organic frameworks and coordination polymers (MOFs/CPs) have emerged as a rare category of multidimensional materials with applications in many fields, particularly as photocatalysts for aromatic dyes and for the luminescent sensing of volatile organic solvents (VOCs), anions, cations, etc. Herein, a luminescent zinc(II) coordination polymer (ZnCP) was prepared using 3,5-diamino triazole (DAT) and 1,3,5-benzenetricarboxylic acid (BTC) under solvothermal conditions and was fully characterized by FTIR spectroscopy, powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), Brunauer–Emmett–Teller (BET) analysis, and single X-ray crystallography. Moreover, the photocatalytic performance of the ZnCP in decomposing an aqueous solution of methyl green (MG) was examined. Photocatalysis results indicated a 99.61% efficiency in the presence of the ZnCP under visible light. Furthermore, an active species trapping experiment helped deduce a possible photocatalysis mechanism of MG degradation. Interestingly, the ZnCP also acted as a potential luminescent sensor for the detection of cations Fe3+ and Cu2 and anions Cr2O72− and MnO4−, with outstanding limit of detection (LOD) values of 2.44 nM for Fe3+, 3.50 nM for Cu2+, 3.14 nM for Cr2O72−, and 2.54 nM for MnO4−. Thus, the designed luminescent zinc(II) coordination polymer holds the potential to act as a photocatalyst as well as a luminescent sensor. [ABSTRACT FROM AUTHOR]

This study reports magnetic graphene oxide composite microspheres (MGO) were firstly synthesized via one step miniemulsion polymerization. α-FeOOH rods were then loaded onto MGO via a facile hydrothermal method to prepare α-FeOOH@MGO, which was served as the photocatalyst for the Fenton reaction. Subsequently, the properties of the resulting α-FeOOH@MGO were characterized by FT-IR, XRD, SEM, VSM and UV-vis DRS analysis methods. The influence of various parameters was investigated, such as dye type, dye concentration, H2O2 dosage, catalysts dosage and pH of MO solution during heterogeneous photo-Fenton processes. Under visible light irradiation, the degradation rate of MO, MB and CR could reach 99.96%, 98.47% and 99.97% in 40 min, respectively. Six cycle experiments confirmed that the α-FeOOH@MGO possessed a satisfied stability and recycling ability. In addition, the photocatalytic reaction mechanism was also revealed by the Mott-Schottky plot, band structure and trapping experiments of active species. [ABSTRACT FROM AUTHOR]

The development of a highly efficient catalyst for water splitting and photodegradation of organic dyes has become the focus of a considerable number of research groups. In the work described here CdZnS@MIL-53(Fe) and ZnS@MIL-53(Fe) were synthesized by the solvothermal method and subjected to thermal degradation at 520 °C in an oxidative environment to obtain CdZnS/Fe 2 O 3 and ZnS/Fe 2 O 3 , respectively. Electrocatalytic activity for the oxygen evolution reaction is analyzed via cyclic voltammetry and linear sweep voltammetry. It was found that CdZnS@MIL-53(Fe) shows maximum catalytic activity for the oxygen evolution reaction and delivers 10 mAcm−2 current density at 95 mV overpotential as compared to MIL-53(Fe)/NF (210 mV) and ZnS@MIL-53(Fe)/NF (112 mV). Similarly, the derivative of it, CdZnS/Fe 2 O 3 , shows maximum catalytic activity for the oxygen evolution reaction and delivers 10 mAcm−2 current density at 90 mV overpotential as compared to Fe 2 O 3 (204 mV) and ZnS/Fe 2 O 3 (115 mV). Based on these results, it is evident that these materials are highly efficient for OER activity compared with other materials in literature. Similarly, CdZnS/Fe 2 O 3 shows maximum photocatalytic activity for the photodegradation of Rhodamine B, up to 75% compared to CdZnS@MIL-53(Fe), which degrades up to 51% of the dye. The synthesized materials were characterized by powdered X-ray diffraction, Fourier transform infrared spectroscopy and scanning electron microscopy. Based on these results the aim is to develop more MOF-based materials and their derivatives by simple heat treatment and to implement them in different catalytic applications. [Display omitted] • Designing of highly efficient catalysts by in-situ incorporation of CdZnS nanoparticles in (MIL-53(Fe). • The newly designed CdZnS@MIL-53(Fe) and its derivative CdZnS/Fe 2 O 3 showed efficient OER activity. • The CdZnS/Fe 2 O 3 is also effective forphotodegradation of Rhodamine B (up to 75% in just 80 min). • The better catalytic activity is due to formation of heterojunction between CdZnS and MIL-53(Fe) or its derivative. [ABSTRACT FROM AUTHOR]

MoP as an important transition metal phosphide material, has been widely used in catalysis field due to its excellent catalytic performance and chemical stability. Combining MoP with carbon material can effectively enhance its dispersibility and stability, as well as the carrier transport rate, thereby further improving its photocatalytic performance. In this study, MoP/C nan-osheets were prepared by the sodium chloride template method, and its photocatalytic ability to degrade methylene blue was studied by adjusting the amount of MoP/C added. The results showed that MoP was uniformly distributed on the surface of the carbon nano-sheets to form the composites. The highest removal efficiency of MB (20 mg/L, 200 mL) was observed when 5 mg of MoP/C was added and reacted for 4 h under 6 °C light, reaching 70.7%, At the same time, this study systematically investigated the active substances produced during the photocatalytic degradation of methylene blue, and found that ·OH and ·O2− play a key role in the photocatalytic process. Furthermore, MoP/C also used to photocatalytic degradation of tetracycline hydrochloride and diplayed good photocatalytic performance. This study provides new ideas for the application of transition metal phosphides as photocatalyst in the environmental and energy fields. [ABSTRACT FROM AUTHOR]

Wastewater pollution caused by organic dyes is a growing concern due to its negative impact on human health and aquatic life. To tackle this issue, the use of advanced wastewater treatment with nano photocatalysts has emerged as a promising solution. However, experimental procedures for identifying the optimal conditions for dye degradation could be time-consuming and expensive. To overcome this, machine learning methods have been employed to predict the degradation of organic dyes in a more efficient manner by recognizing patterns in the process and addressing its feasibility. The objective of this study is to develop a machine learning model to predict the degradation of organic dyes and identify the main variables affecting the photocatalytic degradation capacity and removal of organic dyes from wastewater. Nine machine learning algorithms were tested including multiple linear regression, polynomial regression, decision trees, random forest, adaptive boosting, extreme gradient boosting, k-nearest neighbors, support vector machine, and artificial neural network. The study found that the XGBoosting algorithm outperformed the other models, making it ideal for predicting the photocatalytic degradation capacity of BiVO4. The results suggest that XGBoost is a suitable model for predicting the photocatalytic degradation of wastewater using BiVO4 with different dopants. [ABSTRACT FROM AUTHOR]

Dye pollution resulting from the discharge of untreated wastewater has become a major environmental concern. In this study, we propose a green and cost-effective approach for the photocatalytic degradation of dye pollutants using a nanocomposite (NC) of manganese oxide (Mn3O4) modified with polyvinylpyrrolidone (PVP). The Mn3O4 nanoparticles (NPs) were synthesized through a green method using a biogenic extract of Pistacia lentiscus leaves. The resulting Mn3O4 NPs were then modified with PVP, a non-ionic polymer, to enhance their stability and catalytic performance. The synthesized Mn3O4/PVP NC was characterized using various analytical techniques, including Fourier transform infrared spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy. The findings showed that the Mn3O4 NPs and Mn3O4/PPV NC exhibit spherical morphology with an average size of 37 nm and 45 nm, respectively. The Mn3O4 NPs and Mn3O4/PVP NC exhibited optical bandgap energies of 1.8 eV and 1 eV, indicating the effective use of these NPs as photocatalysts. The nanocomposite exhibited exceptional catalytic performance in degrading bromophenol blue (BPB) and ortho-toluidine blue (O-TB), achieving degradation rates of 98% and 95% within 75 minutes. In comparison, Mn3O4 NPs showed lower efficiencies with approximately 14% degradation for BPB and 6% for O-TB. Optimal conditions for dye degradation and subsequent cycles were determined, and first-principles calculations revealed insight into the adsorption energy between the dyes and the Mn3O4/PVP surface. This study highlights the potential of Mn3O4/PVP nanocomposite as an effective and eco-friendly catalyst for dye pollutant degradation, offering a promising solution for wastewater treatment across industries. [ABSTRACT FROM AUTHOR]

In this study, pure CdO nanoparticles, magnetic Fe3O4 nanoparticles, and Fe3O4-CdO nanocomposites were prepared via a solution combustion method using cetyltrimethylammonium bromide (CTAB) as a template. These prepared nanomaterial samples were characterized by X-ray diffraction (XRD), ultraviolet-visible diffuse reflectance spectroscopy (UV-vis DRS), Fourier-transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray photoelectron microscopy (XPS), transmittance electron microscopy (TEM), and scanning electron microscopy (SEM) analysis. XRD patterns confirmed the purity and the crystalline nature of the prepared samples. FTIR and Raman spectra observed the metal-oxygen (M-O) bond formation. UV-vis DRS studies were performed to investigate the optical properties and the bandgap energy determination. The surface morphology and the size of the pure CdO nanoparticles, magnetic Fe3O4, and nanocomposites of Fe3O4-CdO were determined via TEM and SEM analysis. Under optimum experimental conditions, the Fe3O4-CdO nanocomposites were applied for photocatalytic activity against Methylene blue dye. Under visible light irradiation, Fe3O4-CdO nanostructures showed an efficient photocatalytic degradation of 92% against Methylene blue organic dye and showed excellent stability for multiple cycles of reuse. [ABSTRACT FROM AUTHOR]

Historically, the photocatalytic efficacy of graphitic carbon nitride (g-C3N4) has been constrained by a rapid charge recombination rate and restricted sensitivity to visible light. To overcome these limitations and enhance the performance of g-C3N4, the strategic formation of heterojunctions with semiconductor materials is deemed the optimal approach. The present study employed a facile sonication-assisted pyrolysis method to synthesize a g-C3N4@ZrO2 nanocomposite photocatalyst. This hybrid material was characterized extensively using a comprehensive suite of analytical techniques, including XRD, SEM, EDX, FTIR, and UV-Vis DRS. A comparative analysis of photocatalytic applications under identical conditions was conducted for all synthesized materials, wherein they were subjected to UVc light irradiation. The photocatalytic degradation of various dye models, such as MB, EY, and a combination of dyes, was assessed using the prepared nanocomposites. The g-C3N4@ZrO2 photocatalysts showcased superior photocatalytic performance, with a particular variant, g-CNZ6, exhibiting remarkable activity. With a bandgap energy of 2.57 eV, g-CNZ6 achieved impressive degradation efficiencies of 96.5% for MB and 95.6% for EY within 40 min. Following previous studies, the superoxide radical anions (O2−. and h+) were largely accountable for the degradation of MB. Therefore, the observed efficacy of the g-C3N4@ZrO2 nanocomposite photocatalyst can be attributed to the increased generation of these reactive species. [ABSTRACT FROM AUTHOR]

These days, textile industries pose a more significant threat to surface water and groundwater sources directly or indirectly by discharging wastewater containing various dyes and organic pollutants to these water sources. The phase-junction-engineered heterogeneous photocatalysis carried out by visible light-driven semiconductor photocatalysts is opening a new window for the degradation of environmental organic pollutants. In this work, we have reported a one-step bottom-up hydrothermal synthesis of biphasic tungsten oxide (o/h-WO3) and performed a photodegradation experiment under visible light irradiation for the efficient degradation of organic pollutants such as Methylene blue (MB) and Methyl violet (MV), respectively. The X-ray diffraction, RAMAN, transmission electron microscopy and ultraviolet–Vis characterization techniques were used to investigate the structural, morphological and optical properties of the as-synthesized o/h-WO3. Moreover, the low calculated band gap (∼2.8 eV) and the anionic nature of o/h-WO3 suggest it as an efficient visible light-driven photocatalyst suitable for heterogeneous photocatalysis. The photodegradation experiment performed under visible light using o/h-WO3 photocatalyst showed better degradation efficiency of 71% and 89% for MB and MV, respectively, in 100 min. The dyes followed first-order kinetics, and their kinetic rate constants were calculated using the Langmuir–Hinshelwood model. Furthermore, the recyclability study of the photocatalyst was also performed and discussed the underlying mechanism for the photodegradation of the organic dyes. [ABSTRACT FROM AUTHOR]

Considering the strong sunlight-absorption property of WS2 and the good photocatalytic activity of BiOCl, a solar-light-active Z-scheme BiOCl@WS2 nanocomposite photocatalyst was synthesized by a precipitation approach. The developed photocatalyst was systematically characterized using available precision instruments. The photocatalytic property of the synthesized photocatalyst toward methyl orange (MO), rhodamine B (RhB), and crystal violet (CV) as anionic and cationic model organic dyes was investigated. In addition, the influence of operational factors, such as the catalyst dose, dye concentration, and pH, on the photocatalytic performance of the proposed photocatalyst was examined. The degree of mineralization of the fabricated Z-scheme BiOCl@WS2 nanocomposite photocatalyst during photodegradation of CV was also evaluated via total organic content (TOC) measurements. The findings showed that the developed Z-scheme BiOCl@WS2 nanocomposite exhibited excellent photocatalytic properties toward the organic pollutants MO, RhB, and CV. Moreover, the nanocomposite exhibited a better photocatalytic activity when compared with that of the solar-light-active photocatalysts reported in the open literature. It also displayed the potential to photocatalytically degrade 81% of MO, 100% of RhB, and 95% of CV within 120 min. Besides, 88% of CV could be mineralized by the fabricated photocatalyst in two hours. The outstanding photocatalytic performance of the Z-scheme BiOCl@WS2 nanocomposite could be attributed to the narrow band gap, large surface area, extended optical activity, and suppressed charge recombination rate. Thus, this work opens the door for developing effective, efficient, and stable solar-light-active photocatalysts for the photodegradation of organic dyes in wastewater. [ABSTRACT FROM AUTHOR]

Cobalt aluminate/carbon composite nanoparticles have been synthesised by utilising an auto-combustion method using glycine as an inexpensive fuel. The products were analysed by various techniques such as powder X-ray diffraction (XRD), Fourier transform infrared (FT-IR), thermal analysis (TG), field emission scanning electron microscopy (FE-SEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), UV-Vis diffuse reflectance spectrum (DRS), energy-dispersive X-ray spectroscopy (EDS). The results exhibited that the average crystallite size of the as-prepared CoAl2O4/C nanocomposite was ca. 26 nm. The photocatalytic activity of the as-prepared catalyst was evaluated through the degradation of methylene blue (MB) dye under different conditions, and the photocatalytic degradation mechanism was proposed. The results indicated that CoAl2O4/C nanocomposite has a high catalytic performance for the photocatalytic degradation of MB dye under UV illumination in the presence of H2O2. The degradation efficiency reached 98.5% in 90 min with a degradation rate constant of 0.046 min−1. [ABSTRACT FROM AUTHOR]

Development of nanocomposites as efficient photocatalysts for the removal of hazardous organic pollutants is always in dire demand due to increase in water pollution. In this article, a facile sol-gel method has been used to synthesize cerium oxide (CeO2) nanoparticles followed by their decoration over multi-walled carbon nanotubes (CNTs) and graphene oxide (GO) to construct binary as well ternary hybrid nanocomposites using ultrasonic treatment. The oxygen vacancy defects have been depicted using X-ray photoelectron spectroscopy (XPS) that may result into improved photocatalytic efficiency. The ternary hybrid nanocomposites (CeO2/CNT/GO) showed excellent photocatalytic efficiency towards degradation of rose bengal (RB) dye up to 96.9% in 50 min. CNTs and GO provide the interfacial charge transfer which inhibits the electron-hole pair recombination. The results obtained here indicate that these composites can be effectively utilized as promising materials for the degradation of harmful organic pollutants for wastewater treatment. [ABSTRACT FROM AUTHOR]

The construction of photocatalysts with a Z-scheme heterojunction is considered to be a superior strategy for improving photocatalytic activity. In this study, a photocatalyst (PI/TiC/TiO2) with a Z-scheme heterojunction was fabricated, in which polyimide (PI) and TiO2 were used as the organic/inorganic semiconductor photocatalyst and TiC acted as the transmission bridge for electrons between PI and TiO2. In the self-made air flow photocatalytic reactor, the photocatalytic degradation efficiencies of organic dyes by PI/TiC/TiO2 increased with the increase of both the concentration and diffusion rate of O2. The degradation efficiencies of RhB and MB by PI/TiC/TiO2 reached 93.87% and 90.96%, respectively, within 90 min of visible light exposure, showing its outstanding photocatalytic performance. The mechanism analysis indicated that the Z-scheme heterojunction in PI/TiC/TiO2 facilitated the separation and migration of photoexcited charges while retaining stronger redox capabilities for charge carriers. This study provides an insight into the construction of visible light responsive organic/inorganic photocatalysts with Z-scheme heterojunctions for organic pollution treatment applications. [ABSTRACT FROM AUTHOR]

There is no doubt that organic dyes currently play an indispensable role in our daily life; they are used in products such as furniture, textiles, and leather accessories. However, the main problems related to the widespread use of these dyes are their toxicity and non-biodegradable nature, which mainly are responsible for various environmental risks and threaten human life. Therefore, the elimination of these toxic materials from aqueous media is highly recommended to save freshwater resources, as well as our health and environment. Heterogeneous photocatalysis is a potential technique for dye degradation, in which a photocatalyst is used to absorb light (UV or visible) and produce electron–hole pairs that enable the reaction participants to undergo chemical changes. In the past, various metal oxides have been successfully applied as promising photocatalysts for the degradation of dyes and various organic pollutants due to their wide bandgap, optical, and electronic properties, in addition to their low cost, high abundance, and chemical stability in aqueous solutions. Various parameters play critical roles in the total performance of the photocatalyst during the photocatalytic degradation of dyes, including morphology, which is a critical factor in the overall degradation process. In our article, the recent progress on the morphological dependence of photocatalysts will be reviewed. [ABSTRACT FROM AUTHOR]

Herein, new efficient photocatalysts composed of Cu doped NiS/ZnS quantum dots-composites were synthesized by coprecipitation technique for treatment of organic dyes. Treatment of dyeing-wastewater is an important issue to reduce the environmental pollution and providing a large quantity of pure water. The transmission electron microscope images of pure and Cu doped NiS/ZnS composites show quantum dots particles with size of 3–4 nm. The X-ray diffraction confirmed the formation of cubic ZnS and rhombohedral NiS. Optically, doping by 4 wt% Cu ions was reduced the band gap energy of ZnS from 3.4 to 2.98 eV, which improve the visible light absorption. 4 wt% Cu doped NiS/ZnS nanocomposite reveals a fast and remarkable photodegradation efficiency of 95%, 98% and 97% towards 20 ppm methyl green, methylene blue and Congo red during 60 min of sunlight irradiation. For three cycles, 4 wt% Cu doped NiS/ZnS nanocomposite exhibits significant photodegradation activities of 98%, 92% and 85%, respectively. The improvements of the photocatalytic activity of Cu doped NiS/ZnS nanocomposite can be attributed to some factors including visible-light absorption and charge carriers separation. The Cu doping improves the visible light response of ZnS through reducing the band gap which reinforce the number of the excited electron-hole pairs. Too, Cu ions act as trapping centers (Cu2+ + e → Cu+) which boost the separation of the excited electron-hole pairs and consequently improve the photodegradation activity. This study point out that the integration of p-n heterostructure and doping strategies are efficient for deign of photocatalysts for wastewater treatment. [ABSTRACT FROM AUTHOR]

The development of photocatalysts for organic degradation is a hot research topic. In this study, CdZnS was selected as the carrier, and ZIF-8 was combined with it to explore the photocatalytic performance of the composite. In addition, the compound material, CdZnS@ZIF-8, was used as a photocatalyst for the decomposition of methylene blue dye, and the performance of pure CdZnS and pure ZIF-8 was compared. The photocatalytic efficiency of CdZnS@ZIF-8 was significantly higher than that of the other two. In the experimental reaction, the amount of catalyst was 0.04 g, the pH value was 7, the initial concentration of methylene blue aqueous solution was 20 mg/L, and the degradation of methylene blue in 50 mL aqueous solution could reach 99.5% under visible light irradiation for 90 min, showing excellent photocatalytic efficiency in the visible light range. It demonstrated excellent photocatalytic function in the visible light region, and the electron transfer phenomenon at the interface occurred in the het-junction and the separation of the photo-generating electron–hole as an electron acceptor of ZIF-8 further promoted the photocatalytic effect. [ABSTRACT FROM AUTHOR]

From the perspective of environmental protection, the highly efficient degradation of antibiotics and organic dyes in wastewater needs to be tackled as soon as possible. In this study, an ecofriendly and green cube-shaped cobalt-doped zinc oxide nanoparticles (Co–ZnO NPs) photocatalyst using Pterocladia Capillacea (P. Capillacea) water extract loaded with 5, 10, and 15% cobalt ions were formed via co-precipitation process to degrade antibiotics. The prepared Co–ZnO NPs were tested as a photocatalyst for the photodegradation of ciprofloxacin (CIPF) in the presence of a visible LED-light source. Co–ZnO NPs have been obtained through the co-precipitation method in the presence of P. Capillacea extract as a green capping agent and reducing agent, for the first time. Several characterization techniques including FTIR, XRD, BET, XPS, TEM, EDX, SEM, TGA and DRS UV–Vis spectroscopy were applied to study the prepared Co–ZnO NPs. XRD results suggested that the average size of these NPs ranged between 42.82 and 46.02 nm with a hexagonal wurtzite structure. Tauc plot shows that the optical energy bandgap of ZnO NPs (3.19 eV) gradually decreases to 2.92 eV by Co doping. Examinations showed that 5% Co–ZnO NPs was the highest efficient catalyst for the CIPF photodegradation when compared with ZnO NPs and other 10 and 15% Co–ZnO NPs. A 10 mg/L solution of CIPF was photo-degraded (100%) within the first 15 min irradiation. The kinetics showed that the first-order model is suitable for displaying the rate of reaction and amount of CIPF elimination with R2 = 0.952. Moreover, central composite design optimization of the 5% Co-doped ZnO NPs was also investigated. [ABSTRACT FROM AUTHOR]