Search

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

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]

Here, the zinc sulfide–copper sulfide (ZnS–CuS) nanocomposites have been synthesized using immersing thin layers of ZnS in 0.5 (M) Copper (II) chloride solution at low temperature by a simple and cost-effective chemical bath deposition (CBD) method. The immersion time of ZnS thin films in copper (II) chloride solution was investigated based on the structural, morphological, optical and optical catalytic activity of the prepared layers. The results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) confirmed the formation of CuS: ZnS nanolayers consists of nanocrystals with an approximate diameter of less than 10 nm during the immersion time of 1 min. The particles forming the layers are dense and have good adhesion to the substrate. The energy gap of the layers decreases with increasing copper, which can lead to phase formation. Their significant photocatalytic activities in the photodegradation of Rhodamine B (RhB) dye in aqueous media have been considered, because ZnS:CuS nanocomposite thin films showed light catalytic activity in the RhB degradation in presence of visible radiation, so that the percentage of dye degradation is decreased by increasing the amount of copper and the duration of exposure to visible light due to slowing down the recombination rate of electron–hole pairs. While investigating the optical catalytic activity of the layers, there was no need to homogenize and centrifuge the solution to separate the nanoparticles from it. The main aim of this study is consideration of the effects of CuS amount on the photocatalytic activity of ZnS–CuS nanocomposite under the CBD method of synthesis condition. [ABSTRACT FROM AUTHOR]

Dye-contaminated water from industry is hazardous to human and aquatic lives. Membrane technology is considered a viable approach to resolve the issue. Herein, copper oxide nanoparticles (CuO NPs) embedded in porous chitosan membranes have been prepared using a solution-casting approach with sodium tripolyphosphate as a crosslinker and polyethylene glycol as a porogen. The prepared membranes have been characterized by physicochemical, mechanical and photocatalytic properties. FTIR results indicate some hydrogen bonding across CuO NPs and the chitosan matrix. XRD and TGA analyses reveal that the membranes are thermally stable and somehow crystalline. SEM examination indicates that the membrane surfaces express porous/roughened texture. The contact angle measurement indicates that the pure chitosan and CuO NPs-embedded membranes are hydrophobic, whereas PEG-leached porous chitosan membranes express hydrophilicity. CuO NPs reinforcement has significantly improved the tensile strength, whereas the elongation at break decreased. The CuO NPs incorporated in chitosan membranes exhibit exceptional photocatalytic activities against methyl orange and methylene blue dyes for their effective removal from aqueous media. [ABSTRACT FROM AUTHOR]

We synthesized a γ-irradiated chitosan-ZnO-AgNPs (ICZA) composite by using a simple hydrogels method. We evaluated its adsorption/photocatalytic degradation abilities for the removal of an organic dye and its antibacterial activity. The XRD, SEM, TEM, EDS, and FTIR techniques were used to characterize the obtained samples. Based on the adsorption and degradation of methylene blue (MB) in the dark and under UV light irradiation, the adsorption and the photocatalytic activity of the as-obtained samples were evaluated. The optimum conditions for synthesizing the composite were as follows: contact time of 210 min, a dosage of 2 g/L, MB concentration of 40 mg/L, and a solution pH of 8.0. The ICZA had a high adsorption capacity, which was suitable for removing MB from the aqueous solutions; it showed a maximum adsorption capacity (qm) of 92.59 mg/g. The fit of the adsorption isotherms with the Langmuir model was satisfactory. The photocatalytic degradation ability of the composite was also better than that of other catalysts in the presence of UV light, with an apparent rate constant (kapp) of 3.08 × 10−2. The synthesized ICZA also showed good antibacterial activity against Staphylococcus aureus, with a minimum inhibitory concentration (MIC) and a minimum bactericidal concentration (MBC) of 12.5 g/mL and 50 g/mL under light-incubation and dark-incubation conditions. Finally, we discussed the hypothesized mechanism of the adsorption/photocatalytic activity and antibacterial activity of the ICZA composite in this study. [ABSTRACT FROM AUTHOR]

This paper proposes a simple and environmentally friendly method for the green synthesis of SnO2–ZnO/bentonite nanocomposite in the presence of Acroptilon repens flower extract as a reducing and stabilizing agent. The synthesized nanocomposite was characterized using various techniques to investigate their structural properties and morphology. The photocatalytic degradation of the organic dye, eriochrome black-T (EBT) under solar irradiation and in the presence of synthesized nanocomposite was investigated. The results indicated that the nanoparticles were well immobilized onto bentonite as a support with minimum agglomeration. Moreover, the results of photocatalytic reactions showed that SnO2–ZnO/bentonite nanocomposite could remove the dyes in just 2.5 h and the degradation efficiencies approached 100% indicating the excellent performance of the catalyst. The kinetic study revealed that degradation of EBT in presence of the SnO2–ZnO/bentonite nanocomposite obeys first-order kinetics with the rate constant of 1.75 × 10–2 min−1. Furthermore, the biosynthesized nanocomposite exhibited a stable performance and high tolerance to the reaction conditions and was reused in three cycles with negligible loss of activity. [ABSTRACT FROM AUTHOR]

The enhanced photocatalytic process of GMNT NCs was achieved by wet impregnation. The resulting sample was examined using numerous analytical techniques to determine its composition, morphology, structure, and optical properties. GMNT photocatalyst showed impressive photocatalytic degradation efficiency (91.75%) over RhB dye in 100 min, when exposed by visible illumination. The photoreaction rate constant of GMNT ternary PCs (0.0233 min−1) was 6.2 times faster than bare GCN (0.0037 min−1), GMS (0.0055 min−1), and GCNT (0.0124 min−1) against RhB dye. Besides, they have considerable stability against RhB dye degradation after five cycles. A trapping experiment with a variety of scavengers also reveals that photogenerated charge carriers hole pair and ⋅O2− radicals play a prominent role in the photodegradation process. GMNT nanocomposite has been shown to enhance photocatalytic performance by suppressing e−–h+ pair separation and recombination efficiency. Hence, GMNT PCs have shown high potential for various environmental applications, including wastewater treatment. [ABSTRACT FROM AUTHOR]

Water pollution caused by organic dyes is one of the greatest threats to the ecosystem. The removal of dyes from water has remained a challenge for scientists. Recently, metal sulphides have emerged as a potential candidate for water remediation applications. The efficient charge transportation, greater surface-active sites, and low bandgap of metal sulphides make them an excellent choice of semiconductor photocatalysts for degradation of dyes. This review summarises the potential application of metal sulphides and their heterojunctions for the photocatalytic degradation of organic dyes from wastewater. A detailed study has been presented on the synthesis, basics of photodegradation and heterojunctions and photocatalytic activity. The effect of the use of templates, doping agents, synthesis route, and various other factors affecting the photocatalytic activity of metal sulphides have been summarised in this review. The synthesis techniques, characterisation techniques, mechanism of degradation of organic dyes by Z-scheme heterojunction photocatalyst, reusability and stability of metal sulphides, and the scope of future research are also discussed. This study indicates that Scopus-based core gathered data could be used to give an objective overview of the global dye degradation research from 2008 to 2023 (15 years). All data (articles, authors, keywords, and publications) is compiled in the Scopus database. For the bibliometric study, 1962 papers relevant to dye photodegradation by sulfide-based photocatalysts were found, and this number rises yearly. A bibliometric analysis provides a 15-year evaluation of the state-of-the-art research on the impact of metal sulfide-based photocatalysts on the photodegradation of dyes. [ABSTRACT FROM AUTHOR]

In this study, the chemical pechini sol-gel method was used for the simple fabrication of Fe0.5Mn0.5Co2O4/Fe2O3 as a new nanocomposite at 400, 600, 800, and 1000 oC. The fabricated products at 400, 600, 800, and 1000 oC were encoded as E400, E600, E800, and E1000, respectively. The fabricated nanocomposites were identified using several devices such as XRD, N2 adsorption/desorption analyzer, FT-IR, EDS, UV–Vis diffuse reflectance spectrophotometer, and field emission scanning electron microscopy. The average crystallite size of the E400, E600, E800, and E1000 products is 80.31, 123.25, 130.75, and 141.36 nm, respectively. The FE-SEM showed that the E400 sample consists of rods, spheres, and irregular forms with an average diameter of 337.50 nm. Also, the E600 and E800 products consist of spheres and irregular shapes with an average diameter of 446.96 and 854.52 nm, respectively. Besides, the E1000 product comprises of cubic, sphere, and irregular shapes with a mean diameter of 1019.88 nm. The synthesized nanocomposites were used for the efficient photocatalytic degradation of safranin dye. In the presence of H2O2, 0.1 g of the synthesized nanocomposites completely decompose 50 mL of about 25 mg/L of safranin dye at pH equals 8 in 25 min. [ABSTRACT FROM AUTHOR]

Using a combination method of roasting process with soda ash (Na2CO3) and hydrochloric acid leaching, a TiO2-based photocatalyst was successfully synthesized from Indonesia ilmenite ore. The study investigated the effect of Na2CO3 ratios, roasting times, and HCl concentration on the physical and photocatalytic properties of the photocatalyst. The results revealed that HCl concentration played a critical role in altering the characteristics of the prepared photocatalyst. TiO2 composition increased by 61% compared to ilmenite ore when 20% HCl was used, whereas Fe2O3 composition decreased by 88%. The physical properties and photocatalytic activity of the prepared TiO2 were similar to those of low-grade commercial TiO2. When conducted to 3 h of low-power (8 W) UV light irradiation, the photocatalyst decomposed Eriochrome Black-T, an organic dye model pollutant, by up to 83%. This study's findings provide crucial implications for further research on recovering TiO2-based photocatalyst from ilmenite ore using a simple method. [ABSTRACT FROM AUTHOR]

The intent of this research work is to implement a biogenic, affordable, and highly effective Ce-Ni@biochar catalyst in order to study its photoactivity in the removal of crystal violet and malachite green oxalate. The catalyst was synthesized using liquid phase reduction method where cerium and nickel nanoparticles are embedded on the rice husk biochar for photocatalytic degradation of organic dyes in the presence of sunshine. Various characterization techniques were conducted on fabricated catalyst for adequate evaluation of the chemical composition as well as morphological and topographical properties of the formed compound. The nanoparticles embedded on biochar persuade increased charge separation that resulted in a substantial decrease in electron-hole recombination rate. The synergistic actions of the catalyst resulted in a high level of photocatalytic activity. The fabricated nanocatalyst showed excellent photoactivity that caused 96 and 99% degradation of crystal violet and malachite green oxalate, a growing industrial pollutant, within 35 and 25 min, respectively. A persuasive mechanism and kinetics are well presented. A series of investigations were done on other factors, such as contact duration, catalyst dosage, starting concentration, interfering ions, and pH, to know its degradation pursuance. The impacts of different water matrices were also investigated. The removal effectiveness of the synthesized catalyst persisted after five consecutive cycles. Marking the burgeoning industrial effluents as a result of rapid industrialization and also focusing on easy availability and low-cost source as well as high efficiency, reusability of the catalyst imparts its novelty and need of this research work. [ABSTRACT FROM AUTHOR]

In this paper, nanocomposite NiO/Cr2O3 has been synthesized by a simple chemical reduction method to study its photocatalytic activity under sunlight irradiation. Various advanced analytical techniques including powder X-ray diffraction (PXRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive spectroscopy (EDS), elemental mapping, Fourier transform infrared spectroscopy (FTIR), and UV-visible spectroscopy have been utilized to characterize the synthesized NiO/Cr2O3 nanocomposite. SEM images show the sheet-shaped morphology of NiO/Cr2O3 nanocomposite. These sheets have a rough surface with nano to micro size cracks. These cracks play important role in the enhancement of photocatalytic activity by increasing surface active sites for the adsorption of dye molecules on the surface of the photocatalyst. The organic dyes crystal violet (CV) and methylene blue (MB) have been chosen to study the photocatalytic behavior of NiO/Cr2O3 nanocomposite under sunlight irradiation. The photocatalytic efficiency of NiO/Cr2O3 nanocomposite has been obtained 88.47% and 93.63% against crystal violet and methylene blue respectively. The results of the photocatalytic kinetics exhibit that degradation rate constant value for crystal violet dye is higher as compared to methylene blue dye. Obtained kinetic results indicate that synthesized nanocomposite acts as an efficient photocatalyst for the degradation of both crystal violet dye and methylene blue dye. NiO/Cr2O3 nanocomposite also exhibited reusability and stability for photocatalytic degradation of both organic dyes. Photoelectrochemical measurements as photocurrent, electrochemical impedance spectroscopy (EIS), and Mott-Schottky plot were also performed for synthesized NiO/Cr2O3 nanocomposite. Consequently, this synthesized NiO/Cr2O3 nanocomposite can be utilized for environmental remediation of harmful dyes. [ABSTRACT FROM AUTHOR]

In this paper, we present the first attempt to evaluate the role of carboxymethyl cellulose (CMC) as a chelating agent in the sol–gel auto-combustion method of producing barium hexaferrite (BaFe12O19). We also report the application of the system as a photocatalyst for dye degradation. The formation, morphology, and crystalline structure of the synthesized nanoparticles are determined using XRD, SEM, EDS, VSM, FTIR, and TEM techniques. High efficiency under visible light, with a band gap of 1.62 eV and a BET surface of 17.93 m2/g, has been observed for the BaFe12O19 catalyst. The operating parameters, such as reaction time, initial dye concentration, light intensity, reusability, and dye type, are studied. Degradation rates as high as 98.26% (Kapp = 0.082 min–1) and 89.07% (Kapp = 0.0743 min–1) were obtained for cases of methylene blue and malachite green under conditions of visible light irradiations when BaFe12O19 was used. The BaFe12O19 catalyst has been shown to exhibit a high degradation performance for cationic dyes. Furthermore, BaFe12O19 magnetic nanoparticles show excellent reusability for dye degradation because the photocatalyst did not exhibit a significant decrease in its activity even after five runs (81.56%). As a result, the current study confirmed that photocatalytic degradation was a promising technology for saving water and treating wastewater formed from textile dye industries. The technique can be used to study the efficiency of photocatalytic degradation and understand the process of recycling waste effluents under conditions of minimized water use. [ABSTRACT FROM AUTHOR]

Aquatic ecology has been greatly threatened by the discharge of effluents of textile and antibiotic industries into natural waters. Herein, an efficient and easily recycled reduced graphene oxide/zirconium oxide nanocomposite has been synthesized using banana peel extract (abbreviated as rGO–ZrO2 in this work). The X-ray diffraction (XRD), field emission scanning electronic microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), Brunauer–Emmett–Teller (BET), UV–visible diffuse reflectance spectroscopy (DRS), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FTIR) spectroscopy were used to analyze the synthesized material. The as-prepared rGO-ZrO2 nanocomposite was employed as a photocatalyst for the decomposition of rhodamine blue (RhB) and crystal violet (CV) dyes, and ciprofloxacin (CIP) antibiotic by illumination with direct sunlight. The RhB and CV were degraded to maximum extent of around 86 and 90%, respectively, over the rGO–ZrO2 nanocomposite after exposure to direct sunlight for 120 min. On the other hand, the degradation of CIP was approximately 93.1% over the rGO–ZrO2 nanocomposite in 240 min under same experimental conditions. Further studies were performed regarding the role of parameters like pH, catalyst dose, and scavengers, in order to understand the superiority of rGO-ZrO2 nanocomposite in degrading organic pollutants. Moreover, the intermediate products and plausible CIP degradation mechanisms were examined using liquid chromatography-mass spectrometry (LC–MS). Moreover, the catalyst was easily separated from the solution and demonstrated good stability and reusability. The RhB, CV, and CIP removal efficiency were 80%, 83%, and 88%, respectively, after five cycles. [ABSTRACT FROM AUTHOR]

In this work, two new copper-based coordination polymers (CPs), {[CuI(H2PO4)(dpe)]5(dpe)0.5(H2O)7}n (Cu-dpe(I)) and {[CuII(HPO4)(dpe)(H2O)](H2O)3}n (Cu-dpe(II)) (dpe = 1,2-di(4-pyridyl)ethylene), had been successfully constructed by hydrothermal method and solvent evaporation method, respectively, and their crystal structures were determined by single crystal X-ray diffraction. The differences of structure and properties between these two coordination polymers were discussed. The synthetic temperature caused their structure differences. They both exhibit excellent photocatalytic activity toward the degradation of methylene blue (MB) under visible light. The degradation rates of Cu-dpe(I) and Cu-dpe(II) to MB in 120 min under visible light were 88.1% and 97.2%, respectively. Some active free radicals such as ·OH, ·O2−, e− played an important role in degradation of MB. In addition, luminescent experiment revealed Cu-dpe(I) exhibits a relatively high sensitive and selective detection of Fe3+ ions in water solution via fluorescence quenching which was caused by competitive absorption of excitation wavelength energy between Fe3+ and Cu-dpe(I). [ABSTRACT FROM AUTHOR]

Vanadium-doped zinc sulfide quantum dots complexed with TiO2 have been designed using the sol–gel technique and characterized using analytical techniques, such as X-ray diffraction analysis (XRD), UV–Vis diffuse reflectance spectra (DRS), Fourier transforms Infra Red (FTIR), Brunauer–Emmett–Teller analysis (BET), X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM), and transmission electron microscopy (TEM). The X-ray diffraction analysis of the composite material showed sharp peaks corresponding to both TiO2 and ZnSQDs. The FTIR analysis exhibits a strong and broad absorption at 807 cm−1 indicating the assimilation of vanadium metal in the ZnSQDs lattice. The DRS spectra showed a bathochromic shift of 25 nm in the synthesized V-ZnSQDs@TiO2 composite compared with the pure sample. The photocatalytic performance of the synthesized composite was tested by studying the degradation of two different chromophoric organic dyes, rhodamine B (RhB), methylene blue (MB) and a drug derivative paracetamol (PCM) in aqueous suspension under UV-light illumination. Among the synthesized materials, the composite (V-ZnSQDs@TiO2) was established to be more active than the pure ZnSQDs, TiO2, and V-ZnSQDs for the degradation of compounds under investigation. The activity of the synthesized catalyst was also tested for the mineralization of all compounds by measuring the depletion in total organic carbon (TOC) at different irradiation times. The results showed that the catalyst degrades the compounds and mineralizes them efficiently. The primary reactive species involved in the photodegradation reaction were determined by quenching studies, terephthalic acid, and NBT probe methods. A probable mechanistic pathway for the decomposition of compounds has been proposed. [ABSTRACT FROM AUTHOR]

Water pollution is a real threat to existence of life on earth. Among major water pollutants, hazardous organic dyes present in industrial effluents need to be immediately addressed. These dyes can be photodegraded using nanocatalysts. Metal-based nanocatalysts are preferred for photocatalytic applications due to their high surface area and suitable energy band gap to produce and sustain photo-generated electrons and holes. Therefore, AgNPs of different morphology (cubic and rod shape) has been reported in current study. AgNPs in form of nanocubes and nanorods have been synthesized by polyol reduction method using ethylene glycol as reducing agent and polyvinylpyrrolidone (PVP) as capping agent. Effect of etchants (KCl and FeCl2) was studied on the morphology of AgNPs. The prepared nanocubes and nanorods were characterized by UV-visible, powder X-ray diffraction (PXRD), and scanning electron microscope (SEM). Nanocubes and nanorods were eventually evaluated for their photocatalytic potential under sunlight irradiation. Silver nanorods were found more active for photocatalytic degradation of methylene blue (MB) dye with 88% degradation after 110 minutes. Antibacterial potential of AgNPs was also evaluated by disk diffusion method against gram-positive and gram-negative strains. AgNPs were found more noxious against gram-negative bacterial strains. [ABSTRACT FROM AUTHOR]

Tetracycline (TC) is a frequently administered antibiotic in many countries, due to its low price and excellent potency. However, certain antibiotics can be hazardous to living creatures due to their accumulation by complexation with metal ions which can contribute to teratogenicity and carcinogenicity. In this investigation, copper oxide-ferric oxide nanocomposite (CuO/Fe2O3 nanocomposite) was synthesized employing Psidium guajava (P. guajava) leaf extract as a reductant as well as a capping agent in an environment friendly and economical green synthesis method. The as-synthesized CuO/Fe2O3 nanocomposite was comprehensively characterized using various sophisticated techniques and its efficiency as a photocatalyst for degradation of tetracycline (TC) antibiotic and toxic dyes, i.e., rhodamine B (RhB) and methylene blue (MB) were investigated. The CuO/Fe2O3 nanocomposite exhibited exceptional efficiency for degradation of TC antibiotic (88% removal in 80 min), RhB (96% removal in 40 min), and MB (93% elimination in 40 min) with apparent rate constant of 0.048, 0.068, and 0.032 min–1, respectively. In the degradation experiments, photocatalytic activity of CuO/Fe2O3 nanocomposite was studied by varying different factors such as time of contact, catalyst dose, and solution pH. The role of reactive species in antibiotics and dye degradation was validated by radical scavenging studies which indicated that.OH radical played a critical role in photocatalytic decomposition. Furthermore, liquid chromatography-mass spectrometry (LC–MS) investigations were employed to anticipate a plausible mechanism for TC degradation. [ABSTRACT FROM AUTHOR]

By integrating the benefits of poly vinyl alcohol (PVA) and chitosan (CS) with α-MnO2 nanoparticles (MNPs), a novel type of nano-polymer composite (PVA/CS-MNP) membrane was synthesized through a simple and facile casting method. In this proposed work, the membrane prepared was used for removal of organic textile dyes from their aqueous solutions. The as-synthesized PVA/CS-MNP membrane was examined using different analytical techniques such as Fourier transform infrared spectroscopy (FTIR) and field emission scanning electron microscopy (FESEM), and mechanical properties of material was also studied. Two cationic dyes, methylene blue (MB) and eosin yellow (EY), were chosen as template dyes to be removed from industrial waste water. These dyes were degraded by carrying out a reaction in which the synthesized membrane was used as a photocatalyst. The study of kinetics revealed that the reaction process followed pseudo-first-order kinetics. The efficiency of catalyst and the rate of reaction were also examined by varying parameters such as pH, initial concentration of dyes, and composition of membrane. The maximum efficiency of catalyst was observed at pH 12 as more than 95% of dyes degraded within 1 h of time span. The catalyst was found to be reusable as its efficiency did not deteriorate even after using it for several times. Such functional membrane having higher stability, low production cost, excellent efficiency to degrade dyes, and good recyclability are promising material for distinctly effective deletion of organic dyes from waste water. [ABSTRACT FROM AUTHOR]

A novel n-MgFe2O4–n-ZnS heterojunction catalyst was employed via two step approach for photodegradation of organic dyes such as Methylene Blue (MB) and Crystal Violet (CV) dyes under visible light irradiation. The synthesized MgFe2O4/ZnS NCs were characterized using PXRD, FTIR, UV–Visible spectroscopy, PL and FESEM analysis which reveals the formation of flake like structure with size as to be ~ 50 nm. The photocatalytic experimental result demonstrates that the MgFe2O4/ZnS nanocomposites (NCs) improve photodegradation performance with 98.0% and 91% decomposition of MB and CV dyes within 120 min illumination during simulated visible light irradiation. From the result, MgFe2O4/ZnS NCs has higher photocatalytic performance than that of MgFe2O4, and ZnS due to efficient separation of the photo-induced electron–hole pairs and effective electron–hole generation transfer by the formation of n-MgFe2O4–n-ZnS heterojunction. Hence, photodegradation performance implies that the synthesized MgFe2O4/ZnS NCs can be effectively utilized in waste water purification systems. [ABSTRACT FROM AUTHOR]

The recent observation of global warming is a crucial concern due to the organic pollutants discharged from various industries. In the current study, nitrogen-doped graphene quantum dots (N-GQDs)@MnCo2O4 nanocomposite was prepared using the hydrothermal and co-precipitation methods and the phase structure, morphology, elemental analysis, charge separation, functional groups, and bandgap were determined using physicochemical characteristics. Results revealed the optical and morphological properties of N-GQDs@MnCo2O4 nanocomposites. N-GQDs were found to have an impressive effect on the bandgap and photocatalytic activity of MnCo2O4. The bandgap of the N-GQDs@MnCo2O4 nanocomposite is about 1.92 eV. The prepared N-GQDs emitted a bright and tunable fluorescence and had a high quantum yield of 17%. In the next step, prepared nanocomposites were applied for photodegradation of acid blue, crystal violet, and methylene blue as model organic contaminants. It has been demonstrated to be an effective photocatalyst for dye degradation when illuminated by visible light. Furthermore, the N-GQDs@MnCo2O4 photocatalyst exhibited high stability, with only a 10% loss of activity after five cycles. Moreover, various radical scavenging agents were used to examine the active radicals present in the photocatalyst used to initiate the photocatalytic process. This new type of photocatalyst provides better and more efficient performance for the degradation of organic dye pollutants. [ABSTRACT FROM AUTHOR]

In this study, a series of ternary composite photocatalysts ZnO/g-C3N4/AgCl(x) (x is the amount of AgCl added, x=0.05, 0.1, 0.15 g) were synthesized, and various characterization methods were used to analyze the morphology, structural, and photochemical properties of the above samples. The photocatalytic activity of the obtained samples was evaluated by degrading rhodamine B (RhB) and acid orange (AOII) under xenon lamp irradiation. The results show that the degradation rate of ZnO/g-C3N4/AgCl (0.1 g) is 99% within 60 min, which is much higher than the 38% degradation rate of g-C3N4. After five cycles, the degradation efficiency of RhB and AOII by ZnO/g-C3N4/AgCl (0.1 g) were still 85% and 94%, respectively. In addition to colored dyes, the photocatalytic degradation of colorless tetracycline hydrochloride (TCH) compounds was also investigated to understand the effect of photosensitization on the degradation process. Based on the electronic structure analysis of the DFT calculations, a staggered heterojunction structure was found between g-C3N4, ZnO, and AgCl. The enhanced photocatalytic activity of the ternary composite is mainly attributed to the efficient separation of charge carriers through the synergistic removal of photogenerated electrons in g-C3N4 by ZnO and AgCl. Radical trapping experiments confirmed that •O2− and h+ were the main active species in the reaction system. As a visible light-responsive catalyst, ZnO/g-C3N4/AgCl can be effectively applied to the degradation of organic dye pollutants and has broad application prospects. [ABSTRACT FROM AUTHOR]

In this work, 2,6-diaminoanthraquinone (DAAQ)-1,3,5-triformylphloroglucinol (TFP) COF/CuS heterojunction was supported on cellulose fibers with hyperbranched polyamide-amine (HPAMAM) as growth template and stabilizer to prepare composite paper for photocatalytic degradation of organic dyes in water. HPAMAM was grafted onto dialdehyde cellulose fibers (DACF) via Schiff base reaction. The intramolecular cavities of HPAMAM provided suitable sites for the growth of COF/CuS heterojunction, and the flexible polymer chains of HPAMAM were used to disperse and stabilize the COF/CuS heterojunction. COF provided an ideal framework for the adsorption, diffusion, and activation of organic dyes in water. And the photogenerated electron transfer path in the COF/CuS heterojunction formed a Z scheme model, which enhanced the separation efficiency of photogenerated electrons and maximized the redox potential for high photocatalytic activity. The DACF/HPAMAM/COF/CuS paper exhibited the highest photocatalytic reaction rate (k = 0.5549 min−1), 7.4 times higher than that of DACF/HPAMAM/COF paper and 6.2 times higher than that of DACF/HPAMAM/CuS paper. To the best of our knowledge, this is one of the best performances for photocatalytic degradation of organic dyes. The DACF/HPAMAM/COF/CuS paper also showed good photocatalytic cycling stability and structural stability. This study provides a strategy for constructing COF/inorganic semiconductor Z scheme heterojunction on cellulose fibers to prepare photocatalytic paper and demonstrates a breakthrough in the field of photocatalytic degradation of organic dyes in water. [ABSTRACT FROM AUTHOR]

Photocatalytic degradation of organic dyes in less-toxic products under visible light irradiation is considered a green method which is widely used in this field. In this manuscript, a novel coordination polymer (PUCP1) based hybrid-nanocomposite (PUCP1@rGO) was synthesized. The PUCP1 and nanocomposite were successfully characterized by using various analytical techniques such as SCXRD, FT–IR, PXRD, TGA, FE–SEM, BET and XPS. The PUCP1 exhibits a 2D framework with an uninodal 4-connected net and sql topology. The PUCP1@rGO was applied as a sensitive and selective photocatalyst for significant degradation of Safranin-O (SO) dye. The rGO played an important role in the expansion of photocatalytic activity of the PUCP1 by inhibiting the recombination probability of electron–hole pairs. The results revealed that PUCP1@rGO nanocomposite can degrade 76% of SO dye in only 90 min under visible light at a neutral pH. The PUCP1@rGO was found very sensitive to photocatalytic degradation of SO dye because a very small amount of catalyst (i.e. 10 mg) degrades the 5 μM concentration of SO dye in the presence of light. The PUCP1@rGO is a reusable photocatalyst for up to 5 cycles. Rarely, any sensitive photocatalyst for SO dye is reported in literature than PUCP1@rGO which degrades SO dye in a very small period with significant quantity. Thus, PUCP1@rGO can be used as a promising photocatalyst for the degradation of SO dye. In this work, we have synthesized a novel coordination polymer (PUCP1) and nanocomposite (PUCP1@rGO) by impreganation of rGO in PUCP1 framework.The PUCP1 exhibited selective photocatalytic response towards safranin-O dye under visible light irradiation and impregnation of rGO enhance the photocatalytic properties of PUCP1@rGO nanocomposite as compared to parent PUCP1.The PUCP1@rGO nanocomposite degrade the safranin-O dye up to 76% in 90 min only under visible light. [ABSTRACT FROM AUTHOR]

Sida rhombifolia leaf extract was used to synthesize heterostructured nanocomposites Ag@CuO/ZnO and Ag@CuO/SnO2 by sol–gel combustion method followed by calcination. Through this ecofriendly approach, we could minimize the utilization of toxic chemicals as the bioactive components present in the plant extract act as capping and complexing agents. XRD studies indicated the formation of various crystalline phases of the congeners of the heterostructured nanocomposites. FESEM studies revealed irregular aggregates for AZC of particle size between 100 and 500 nm whereas uniformly arranged distorted spheres for ASC. The UV-DRS spectra helped to assess the reduced band gap energy from tau plot. The PL emission peaks of ZnO and SnO2 point towards the crystal defects in their lattices. The as-prepared ternary nanocomposites have resistivity to the growth of Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeroginosa, Streptococcus mutans and Staphylococcus aureus with greater inhibition zones which showed their superior antibacterial activity. They are proved to be excellent photocatalysts for the degradation of hazardous organic dyes into harmless products and reduction of aromatic compounds into useful chemicals. Thus, the facile, low-cost and environmentally sustainable green synthesis provides Ag@CuO/ZnO and Ag@CuO/SnO2 nanocomposites with multifunctional efficacy. [ABSTRACT FROM AUTHOR]

In present work, films of CeO2-MnO2 NPs doped PEO-PVP blend have been prepared for photodegradation of organic dyes with low cost, high activity, anti-aggregation and low concentration of nanoparticles compare with other works. The structure, optical and photodegradation characteristics of PEO/PVP/CeO2/MnO2 nanostructures have been studied. The optical properties of PEO/PVP/CeO2/MnO2 nanostructures were studied in the wavelength range (220–720) nm. The results demonstrated that improvement in the structure and optical characteristics with the increase in CeO2/MnO2 NPs. The absorbance increased about 51% while the optical conductivity increased with about 33% with adding of 4.5 wt.% CeO2/MnO2 NPs, this behavior make it use in photodegradation of organic dyes. The refractive index, transmittance, energy gap and real dielectric constants of blend are changed with the increase in CeO2/MnO2 NPs, this behavior is suitable to use in low cost and electronics and optics devices. The allowed and forbidden energy gap of PEO/PVP blend decreased about 45% and 35% respectively with adding of 4.5 wt.% CeO2/MnO2 NPs. The results of photodegradation displayed excellent activity against organic pollutants. [ABSTRACT FROM AUTHOR]

In present research, we designed the novel CuS–CdS/ZnO ternary nanophotocatalysts with various weight percentages of ZnO (80 and 90 wt%) via one-pot sono-hydrothermal method. These nanocomposites efficiently use the sunlight irradiation as a neat and endless energy resource, reduce the recombination rate of the photo-produced e−–h+ pairs, and increase ZnO photocatalytic performance. Furthermore, we synthesized CdS/ZnO, CuS/ZnO, CuS–CdS, and their bare samples and compared their photocatalytic activities with the as-prepared ternary nanophotocatalysts. Fabricated nanophotocatalysts were characterized via X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), energy-dispersive X-ray (EDX), Brunauer–Emmett–Teller (BET) surface area and Barrett–Joyner–Halenda (BJH) pore size and volume analyses, diffuse reflectance spectroscopy (DRS), and point of zero charge pH (pHpzc). Surprisingly, the synthesized ternary nanophotocatalyst with 90 wt% of ZnO (CuS–CdS/ZnO(90)) had the highest photocatalytic activity compared to the other prepared nanophotocatalysts. It removed 97.1% of methylene blue in 140 min. Therefore, using the ternary structure has led to the outstanding photocatalytic performance under simulated sunlight illumination. Additionally, the photodegradation of various dyes, the influence of initial pH solution, and reusability of the optimum photocatalyst were verified in this study. [ABSTRACT FROM AUTHOR]

Nickel–aluminum-layered double-hydroxide (Ni–Al LDH) was synthesized via a facile and green route of co-precipitation. Systematic characterizations of the synthesized material were done by different instrumental techniques. The morphology of the Ni–Al nanomaterial was observed to be sheet-like structures as indicated by FESEM images. From the XRD measurements, it was confirmed that the as-grown nanosheets were Ni–Al LDH nanomaterials with a small quantity of aluminum oxide. Further, the Ni–Al LDH nanomaterial was tested as a photocatalyst for the solar and adsorption-assisted removal of organic pollutants from wastewater. Organic compounds of acridine orange (AO), methyl orange (MO) and cresyl blue (CB) were used as model organic pollutants in this study. Among the three dyes, the Ni–Al photocatalyst was found best for the MO removal while performing the reaction under the dark and visible light conditions. During experiments, it was found that Ni–Al LDH decolorized the MO containing wastewater up to 50% by the process of adsorption performed in the dark conditions. The decolorization efficiency was increased under the visible light as 87% decolorization of MO was achieved from its 0.03 mM solution due to the dye degradation by the action of Ni–Al LDH as a photocatalyst. [ABSTRACT FROM AUTHOR]

The photocatalytic activity of three solvothermal prepared steel slag nanocomposites, SSNP-10, SSNP-20, and SSNP-30, was tested in this work for methylene blue (MB) dye degradation. Using SSNP for the first time, the photocatalytic degradation of MB dye was optimized using Box–Behnken design (BBD) in a response surface approach. The influence of essential operating parameters was experimentally examined, modeled, and optimized. The analysis of variance (ANOVA) results revealed that the suggested quadratic models significantly agreed with the experimental investigation, with p-values less than 0.0001 and an R2 value of 0.9914. Accordingly, the optimized conditions were 32.83 mg catalyst dose, 11.42 pH, 41.34 min irradiation times, and 10.63 mg/L MB dye concentration. The optimized degradation efficiency of the MB dye was 89.43% under these conditions. The result was experimentally validated with the optimal operating parameters for SSNP-10, SSNP-20, and SSNP-30, and the photodegradation efficiencies were 90.07%, 88.94%, and 87.28%, respectively. A pseudo-first-order reaction kinetics of 0.0293, 0.0291, and 0.0267 was achieved for SSNP-10, SSNP-20, and SSNP-30 with a regression coefficient of 0.9514, 0.9312, and 0.9042, respectively. According to Pareto analysis, the operational factors that had the greatest effect on dye degradation efficiency were catalyst dosage (F-value 585.32) > MB concentration (F-value 423.89) > irradiation period (F-value 368.01) > pH (F-value 362.34). The results showed that the SSNP catalyst was the key parameter for the generation of hydroxyl radicals responsible for the photodegradation of MB dye and may be useful for other contaminants' degradation. [ABSTRACT FROM AUTHOR]

In this study, XRD, SEM, TEM, PL, EIS and other characterization methods were used to study the morphology, electron–hole pair recombination efficiency and photocarrier migration rate of the compsite, and analyze the degradation of methylene blue (100 mg/L). Zn0.5Cd0.5S and MoS2 form heterojunction structure, the band gap width decreases a lot, the absorption of visible light is greatly enhanced, the electron–hole recombination efficiency also decreases a lot, and the electron migration rate becomes faster. In the process of photocatalytic degradation of high concentration methylene blue (100 mg/L), the degradation effect of 3%-Zn0.5Cd0.5S/MoS2 is the best, reaching 98.46%, and the degradation rate was 0.0243 min−1. O2−·played a major role in the photocatalytic degradation process. [ABSTRACT FROM AUTHOR]

Incautious discharge of organic dyes such as methyl orange (MO) has produced serious pollution to the environment, calling for the efficient techniques to remove them with retaining the green world. The photo-catalytic degradation of organic dyes is promising among the developed techniques. Thus, a strategy based on transpiration-prompted photocatalytic degradation of dye pollutant under sunlight is put forward. Aniline (ANI) is graft-polymerized onto poly(acrylamide-co-N-4-aminophenylacrylamide) (PAAm) cryogel embedded with gold nanoparticles (AuNPs, diameter: 4–10 nm). The obtained cryogels integrated with AuNPs and PANI inside PAAm matrix (AuNP@PAAm-g-PANI) have been structurally explored based on the chemical composition and the phase/porous morphology. SEM and TEM observation shows that PANI and AuNPs are uniformly distributed in PAAm matrix. Since the macro-porosity of cryogel, hydrophilicity of PAAm and photo-thermal activity of PANI, PAAm-g-PANI cryogels without AuNPs can have a photo-thermal evaporation rate of water at 1.63 kg·m−2·h−1. As a comparison, AuNP@PAAm-g-PANI cryogels with AuNPs exhibit higher one at 2.20 kg·m−2·h−1, suggesting the promotion of AuNPs to photo-thermal evaporation. Meanwhile, PANI appreciatively assists AuNPs to display higher catalytic ability for the oxidative degradation of MO. Therefore, the removal of MO from water is obviously prompted by the water transpiration under sunlight with AuNP@PAAm-g-PANI cryogels, whose rate constant can reach to 0.320 h−1, being three folds of that for the sole absorption of MO. This transpiration-prompted photocatalytic degradation provides a fascinating route to eliminate organic pollutants and obtain pure water from wastewater simultaneously with sustainable sunlight energy. [ABSTRACT FROM AUTHOR]

With the millions of dyes being used in textile industries, there is a challenge for humanity to remediate the waste fluid emerged from these industries and provide a solution to protect the natural water around us. In this context, we report the manufacturing process to develop nanofunctionalized, electroformed tube for the degradation of Azo dyes which are considered as poorly biodegradable industrial pollutants. Copper/graphene oxide electroform tubes have been developed via in-house pulse electroforming setup. Vertically grown ZnO nanorods were synthesized over electroformed electroform tube via chemical synthesis route and were characterized using scanning electron microscopy, energy dispersive spectroscopy, X-ray diffractometer, UV–Vis diffuse reflectance spectrophotometer, and microhardness test. The as-synthesized substrates were utilized for photodegradation of organic dyes under sunlight irradiation. The targeted dyes for evaluation of photocatalytic efficiency are methyl orange (MO), and methylene blue (MB). The results reveal that copper/graphene–zinc oxide electroform tubes provides higher photodegradation efficiency 98.24% in 120 min for MO, and 98.95% in 135 min for MB dye. The proposed functional composite platform can be envisioned for scaling it up for large volume waste water treatment in textile industries. [ABSTRACT FROM AUTHOR]

In our present study, the photocatalytic degradation of malachite green (MG) an organic dye was carried out using a phycocyanin extract of Spirulina platensis under the irradiation of sunlight. The aim of the present study is to incorporate a simple, novel, an eco-friendly, and cost-effective degradation of dyes without using any harmful metals and chemicals. It was observed that 25 ppm of MG dye got degraded nearly to 100 % at 3 h. The UV absorbance studies indicate the absence of a peak at 620 nm which is a conclusive evidence for MG dye degradation. An optimization study of MG dye degradation was evaluated by Response Surface Methodology using Minitab module 20.4.0.0 statistical software and its percentage of degradation was statistically analyzed using analystat. The FT-IR studies of raw spectra show minimal variation; however, the deconvoluted spectra in the region of 1600–1700 cm−1 indicate the variation in the secondary structure of amide I bands that leads to the dye degradation. The dye degradation study mainly follows the first-order kinetics between the time intervals of 60–180 min. The characteristics of degraded water were assessed by a TOC analyzer. The value of total inorganic carbon (TIC) in MG before treatment was 90 mg/L and seems to be slightly high when compared to MG after treatment which was found to be 87.65 mg/L and the adsorbent-treated water with a low value of 54.25 mg/L. These results well matched with the characteristics of normal water. The presence of phycocyanin in the degraded water was effectively removed by treating with activated carbon and it was confirmed with fluorescence analysis. These results support that the MG dye degradation was exhibited by phycocyanin extract and bio-mimics the quantum dot photocatalytic activity. [ABSTRACT FROM AUTHOR]

This paper aims to fabricate of (PEO-PVP) blend doped with SnO2/MnO2 NPs for photodegradation of organic pollutants with low cost, high activity high propagation and anti-aggregation of nanoparticles compare with other materials.The polymer blend was prepared with ratio: 80 wt.% PEO and 20 wt.% PVP. The structural and optical properties of (PEO-PVP-SnO2-MnO2) nanocomposites have been studied in wavelength range (220–820) nm. The photodegradation behavior for (PEO-PVP-SnO2-MnO2) nanocomposites against organic pollutants has been investigated. The results indicated that the absorbance of (PEO–PVP) blend increases about 51% with adding of 4.5 MnO2NPs. The energy gap decreased for allowed and forbidden transitions about 55% and 91%, respectively, by adding of 4.5 MnO2NPs, this behavior is useful for optoelectronics, photocatalysis, the solar cells and diodes fields with low cost and light weight. Finally, the photodegradation activity of (PEO-PVP) blend and (PEO-PVP-SnO2) were increased with increasing of the MnO2 NPs ratios. The (PEO–PVP–SnO2–MnO2) NCs with 4.5 wt% of MnO2 NPs have photodegradation ratio 59%. [ABSTRACT FROM AUTHOR]

Herein, cost-effective TiO2/Cu2O nanoparticles were synthesized via a simple reaction route and applied-for efficient photodegradation of methylene blue (MB) as a model organic dye. Due to the high surface area of TiO2/Cu2O nanoparticles, adsorption and photodegradation properties were evaluated toward MB degradation, showing a high adsorption yield of about 95.7% along with a 100.0% photodegradation efficiency. The effective factors on both adsorption and photodegradation process including pH, initial concertation of organic dye, amount of TiO2/Cu2O nanoparticles, and temperature were optimized via the one-factor-at-a-time optimization method. The photocatalytic performances of TiO2/Cu2O nanoparticles were compared with the activity of both Degussa p25 TiO2 and Cu2O nanoparticles, showing very higher adsorption and photodegradation yields toward dye degradation. It should be noted that the mechanism of the photodegradation of MB on the surface of TiO2/Cu2O nanoparticles was investigated, revealing an adsorption/photodegradation reaction pathway for this phenomenon. [ABSTRACT FROM AUTHOR]

Herein, we prepared the g-C3N4/Gd-doped Bi2WO6 Z-scheme heterojunction (BCN) composites by a simple hydrothermal method. The composites were investigated by SEM (EDX), TEM, XRD, XPS, UV–Vis DRS and PL analysis. The photocatalytic performance of composites was envaulted by degrading methylene blue (MB) under the irradiation of a 300 W mercury lamp. The results demonstrated that coupling g-C3N4 and doping Gd 3+ effectively enhanced the photocatalytic efficiency of pure Bi2WO6. The 92% of MB was degraded within 120 min by optimal 0.15–100 BCN sample, being 1.61 times as that of Bi2WO6. The greatly enhanced performance of 0.15–100 BCN was due to the synergistic effect of Gd 3+ doping and g-C3N4 coupling, which maintained high redox capacity. According to the experiment of capture active species, Z-scheme charge transfer mechanism was also deduced. This study may provide an efficient and green method for the treatment of dyestuff industrial wastewater. [ABSTRACT FROM AUTHOR]

Lysozyme-mediated zinc oxide nanoparticles (LZ NPs) and zinc oxide nanoparticles (Z NPs) were synthesized by a simple wet chemical route for a comparative study of photocatalytic degradation of organic pollutants. We used X-ray diffraction, Fourier transform infrared spectroscopy, zeta potential measurement, field-emission scanning electron microscopy and high-resolution transmission electron microscopy to characterize the synthesized LZ and Z NPs. The synthesized NPs were utilized for photocatalytic degradation of malachite green (MG) and methylene blue (MB) dyes under UV-light irradiation. The photocatalytic performance showed that LZ NPs exhibited 96.80 and 94.03% degradation of MG and MB dyes in 120 min, respectively. Meanwhile, relatively low photocatalytic degradation efficiency 88.60 and 87.02% were observed with Z NPs for MG and MB dyes in 120 min, respectively. Our results showed enhanced photo-degradation activity of the newly synthesized LZ NPs compared to that of Z NPs. [ABSTRACT FROM AUTHOR]