Visible Light Active Photocatalyst Research Articles

Functionalized nitrogen-enrich graphene as a highly efficient photocatalyst for oxidative cyclization of thioamide and degradation of Dye

Functionalized photocatalysts have shown to be an effective method for oxidative cyclization processes and the degradation of organic poisons like chemicals and dyes. In this study, we report the facile, environmentally friendly, room-temperature (RT) synthesis and development of a graphene-based visible light active photocatalyst (NenG-RhB) which is thermodynamically converted to nitrogen-enriched graphene (NenG) covalently bonded to a light-harvesting RhB molecule [9-(2-Carboxyphenyl)-6-(diethylamino)-N, N‑diethyl-3H-xanthen-3-iminium chloride)]. The NenG-RhB photocatalyst is extremely effective, resulting in good oxidative cyclization of aromatic thioamide (92.5 %) and degradation efficiency of industrial orange G (97.29 %) under solar light. The current research focuses on the invention and implementation of a nitrogen-enrich graphene-based photocatalyst for direct solar medicinal chemical synthesis and industrial dye degradation in wastewater using solar light.

Degradation of Methyl Red (MR) dye via fabricated Y2O3–MgO/g-C3N4 nanostructures: Modification of band gap and photocatalysis under visible light

In this study, graphitic carbon nitride (g-C3N4) composites with metal oxide nanoparticles (Y2O3, MgO) and their combination (CN, YCN, MCN and YMCN) were synthesized by an ultrasonic technique and were then characterized by different tools such as UV–Vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) analysis and X-ray photoelectron spectroscopy (XPS). From the XRD diffractograms of the YMCN ternary composite, the g-C3N4, cubic MgO and Y2O3 structural phases were identified. The morphology of the as prepared nanostructure from the SEM analysis revealed the dispersion of the metal oxides nanoparticles with the graphitic sheets and the presence of the corresponding elements were confirmed by the EDX and XPS data. The FT–IR bands confirmed the bonding of the metal oxides to the nitride host as indicated by the characteristic modes. A reduction of the band gap energies was confirmed by the UV–Vis to indicate its visible light possible photoactivity. Accordingly, its visible light driven photocatalytic performance was assessed for methyl red degradation. The degradation competence was highest for the ternary composite YMCN due to the coupling of the semiconductors which increases the absorption and the charge carriers’ separation as well. The kinetics of degradation was best described by pseudo-first-order, and the most active species were the holes and the hydroxyl radicals. Thus, the YMCN nanocomposite is a visible light-active photocatalyst which can be engaged in the degradation of organic pollutants.

Synthesis of magnetic NiFe2O4/rGO heterostructure as potential photocatalyst for a breakdown of malachite green (MG) dye under the visible source of light

The development of reactive radical generators, visible-light active photocatalysts with predictable stability, and efficient activity toward the breakdown of organic pollutant continue to be the primary goals of research in the area of photocatalytic environmental restoration. The present concern to on the development of an efficient heterostructure with a band gap operated on a visible region. The rGO incorporation into spinel material also decreases the agglomeration and provides a large surface area. The efficacy of NiFe2O4 (NF) nanoparticles, which are supported by rGO, as a photocatalyst for the breakdown of malachite green (MG) dye. The incorporation of rGO into NFO was investigated with the band gap property of the fabricated material using Tauc's plot profile. The NF/rGO nanocomposite underwent a reduction in magnetic properties determined through Vibrating Sample Magnetometer (VSM) analysis. However, the coercivity of the nanocomposite experienced a significant increase. When subjected to visible light, the degradation rate of malachite green (MG) dyes with NF/rGO was comparatively faster (93.84 %) than that of NF (64.33 %) and rGO (79.41 %). The cyclic photocatalytic degradation process exhibited notable reusability and stability of the magnetic recycling nanocomposite. The photocatalytic results revealed that the developed nanocomposite acts as a potential photocatalyst and it can also be employed in different applications.

Synthesis and application of Cu-CaTiO3-GO ternary composite: A new visible-light active multifunctional photocatalyst efficient towards antibiotic cefixime degradation and H2 evolution reaction

To combat the issues of energy scarcity and environmental pollution, a visible-light responsive, ternary photocatalyst (Cu-CaTiO3-GO) was fabricated, by photo-depositing Cu nanoparticles over a CaTiO3-GO binary composite. The physicochemical characteristics of Cu-CaTiO3-GO were investigated using XRD, HR-TEM, FE-SEM, EDS-mapping XPS, Raman, FT-IR, BET, EIS, UV–vis DRS, and PL techniques. In comparison with pristine CaTiO3, and binary composites (Cu-CaTiO3, CaTiO3-GO), the ternary hybrid exhibited superior photocatalytic activity for H2generation as well as antibiotic cefixime (CFX) degradation. Under LED light, the rate of H2 generation over Cu-CaTiO3-GO accumulated to 57.69 mmolh−1, while the photodegradation efficiency for CFX reached 94.1 % in 100 min with 53.4 % of TOC removal. The upgraded performance is credited to synergistic effects of Cu NPs (SPR effect), CaTiO3 (specialized cuboid-like morphology), and GO (high conductivity), co-existing in the trio-hybrid, which resulted in a greatly increased surface area, an expanded spectral response range, a stronger adsorption property, efficient charge migration and separation extent. Ternary catalyst performed well even in the 4 recycling tests (retaining 79.4 % CFX removal and 52.51 mmolh−1 H2 evolution efficiency). In Cu-CaTiO3-GO system, the electron transport channel (Cu → CaTiO3 → GO) with adequate band potentials effectively supports both photocatalytic oxidation and reduction. Photoelectrons are enriched and transferred by plasmonic Cu, and then captured by GO, an e- sink. This maximizes composite photo redox capability, rapidly generating active radicals (OH), and (O2-), degrading CFX to simpler molecules and reducing proton to H2. The effectiveness of Cu-CaTiO3-GO was even tested in the real water matrices. Besides, degradation intermediates of CFX were elucidated using LC-MS, and the decomposition pathway was suggested. Finally, the probable photocatalytic reaction mechanism was deduced for both the degradation and H2 generation processes. The current study proposes a non-noble transition metal-based perovskite-type photocatalytic material for both clean energy generation and wastewater treatment.

Enhanced Visible Light Photocatalytic Activity of Exfoliated Boron‐TiO2 Composite for Degradation of Rhodamine B and Nitrogen Fixation

AbstractThe design of an efficient, recyclable, visible light photocatalytic system was examined as a viable new green way to address environmental challenges such as removal of pollutants from wastewater and N2 fixation. The exfoliated boron (Bexf)‐Titanium oxide (TiO2) composite visible light active photocatalysts were successfully constructed via a simple wet chemical method by utilizing acetone as a solvent. The composite was evaluated for the photodegradation of Rhodamine B (RhB) dye and reduction of N2, which exhibits improved photocatalytic activity for degradation of RhB as well as for reduction of N2. Experiments with different quenchers indicate that the photogenerated superoxide radical anion (O2⋅−) plays a significant role in the degradation of RhB as well as for N2 reduction reactions. The composite catalyst shows good photostability and there is no significant reduction of the catalyst activity for dye degradation up to 4 cycles of reaction. This work affords a significant view into the design of reusable TiO2 composite materials for photocatalytic RhB degradation and nitrogen fixation.

Synthesis and characterization of bi-functional Cu and Ni co-doped ZnO photocatalysts for organic pollutant degradation and antimicrobial activity

The study of visible light active photocatalysts for organic pollutants degradation and antimicrobial activity has gained significant attention in recent years. Herein, we report the synthesis of pure ZnO, Ni-doped ZnO (Ni-ZnO), Cu-doped ZnO (Cu-ZnO), and Cu and Ni co-doped ZnO (CuNi-ZnO) photocatalysts via a facile coprecipitation method. These photocatalyst materials were characterized using various analytical techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscope (HR-TEM), Fourier transform infrared spectroscopy (FTIR), UV–visible spectroscopy (UV–Vis), photoluminescence (PL), and total organic carbon (TOC) analysis. XRD patterns confirm the presence of a mixed phase in the CuNi-ZnO sample. The presence of Cu, Ni, and Zn in CuNi-ZnO was verified through the XPS spectra. The nanoparticle-like morphology of the CuNi-ZnO photocatalyst was confirmed using HRTEM analysis. The FTIR spectra reveal the chemical bonds present in the materials. UV–visible spectroscopy was employed to determine the band gap of the materials, revealing a value of 3.10 eV for CuNi-ZnO. The mitigation in recombination of excited electrons (e−) and holes (h+) in CuNi-ZnO is validated through photoluminescence (PL) studies. The synthesized materials were used for the degradation of Indigo carmine (IC) dye and antimicrobial activity. The results showed that the optimized CuNi-ZnO sample displayed a better visible light photocatalytic performance (93.32 % IC dye degradation efficiency in 60 min) than the other samples. A notable degree of mineralization was observed with a reduction in total organic carbon (TOC) reaching 65.91 %. Additionally, the photocatalyst showed antimicrobial activity against both S. aureus and E. coli. Furthermore, a plausible visible light photocatalytic mechanism was proposed for the degradation of IC dye using the CuNi-ZnO photocatalyst.

Innovative ternary composite photocatalyst: BiOCl/Bi12O17Cl2/Bi2O3 for sustainable water remediation

The presence of pollutants in aquatic environments is causing severe health effects on both humans and animals. To address this issue, it has become crucial to develop more efficient and environmentally friendly photocatalysts for the removal of persistent pollutant mixtures from water. In this context, photocatalysts containing more than two bismuth-based materials have rarely been explored for water remediation. With this in mind, we propose an innovative ternary composite, BiOCl-1/Bi12O17Cl2/Bi2O3, as a potentially sustainable visible light-active photocatalyst. Firstly, bismuth oxychloride has been prepared in the presence of ionic liquid, leading to the formation of BiOCl-1 with highly reactive {110} facets. Subsequently, the construction of the ternary composite has been accomplished using a facile and soft hydrothermal approach. The as-prepared BiOCl-1/Bi12O17Cl2/Bi2O3 composite has been successfully used in degrading binary mixtures of contaminants (i.e. ciprofloxacin, methylparaben or methyl orange), achieving an improved visible-light photocatalytic activity compared to single BiOCl-1 and other previously reported bismuth-based photocatalysts. In addition, the photocatalytic mechanism and degradation pathways have been elucidated through scavenger and electrochemical experiments, as well as chromatography-mass spectrometry (LC-MS) analysis, respectively.

Facile synthesis of Cu2S-NiS2 nanocomposite with highly active visible light photocatalyst for dye removal and biological evaluation

Earth abundant metal sulphides such as Cu2S and NiS2 are potential materials to be used as photocatalysts because of their advantageous optical and biological aspects. In this research, a low-cost, high-speed, one step combustion production of novel Cu2S-NiS2 nanocomposite (NCs) was successfully developed. They are integrally characterized and evaluated as photocatalysts for dye degradation and biological uses. The synthesized NCs were characterized by XRD, FTIR, SEM, TEM, EDAX, UV–Visible and PL. XRD data is well matched with JCPDS 03–1071 and 73–574 which correspond to Cu2S and NiS2 nanoparticles (NPs) respectively. FT-IR spectrum exhibits the existence of metal-sulphur bonding in Cu2S-NiS2 NCs. The optical energy band gap of Cu2S-NiS2 NCs was found 2.30 eV. Under visible light irradiation, the photocatalytic activity of Cu2S-NiS2 NCs on rose bengal dye was investigated. Cu2S-NiS2 NCs is more efficient photocatalyst than individual metal sulphide NPs. Also, an important aspect of this study was the exploration of the antimicrobial, antioxidant and antihemolytic properties of pure NPs and Cu2S-NiS2 NCs. The results from the biological screening exposed the fact that the Cu2S-NiS2 NCs demonstrated significantly higher pharmacological activities in comparison to pure NPs.

Solar light-driven photocatalytic degradation potential of g-C3N4 based binary chalcogenides (AgBiS2/g-C3N4)

Fabrication of the AgBiS2 loaded on g-C3N4 was achieved via a hydrothermal route. The novel composite photocatalyst was successfully characterized using Scanning electron microscopy (SEM), Fourier transform infrared (FTIR), Energy dispersive X-ray (EDX), X-ray diffraction (XRD) techniques, and XPS analysis. The synthesized composite (AgBiS2/g-C3N4) was employed for the photocatalytic degradation of methylene blue (MB) under sunlight. The composition of cheaper and visible light active photocatalyst i.e. g-C3N4, with AgBiS2 was advantageous in terms of effective charge separation -due to heterojunction-, and surface morphology. Besides, the energy band gap reduction (owing to the addition of g-C3N4 in AgBiS2) facilitates sunlight-driven photocatalysis. The influencing parameters such as pH, oxidant dose, AgBiS2/g-C3N4 dose, dye concentration, and irradiation time were analyzed for the selection of the well-suited reaction conditions. The interaction of pollutant molecules with the catalyst surface was investigated based on the pHpzc results. Under preferred conditions (such as dye = 10 ppm, pH = 8, catalyst = 40 mg/100 mL, H2O2 = 12 mM, and time = 180 min) the AgBiS2/g-C3N4 exhibited ∼93% photocatalytic degradation of MB. The key radicals were determined using a radical trapping experiment. The reaction kinetic of the proposed study was also studied using 1st and 2nd order kinetic models. The combined influences of effecting parameters were checked by Response surface methodology.

Heterojunction PdO/CoS as a High-Performance Visible-Light Active Photocatalyst Elimination of Methylene Blue from Aqueous Media

Heterojunction PdO/CoS as a High-Performance Visible-Light Active Photocatalyst Elimination of Methylene Blue from Aqueous Media

Photocatalytic degradation of 2,4-dichlorophenol using nanomaterials silver halide catalysts

In this study, the photocatalytic activity of nanomaterials Ag/AgX (X = Cl, Br, I) is reported. Highly efficient silver halide (Ag/AgX where X = Cl, Br, I) photocatalysts were synthesized through a hydrothermal method. The samples were characterized using a range of techniques such as X-ray diffraction (XRD), scanning electron microscopy (SEM), and Brunauer–Emmett–Teller (BET) to check their structural, morphology, textural and optical properties. In addition, the photocatalytic activity of photocatalysts was evaluated through the degradation of 2,4-dichlorophenol (2,4-DCP) under UV and visible light irradiation. XRD analysis confirmed the presence of a single-phase structure (pure phase) in the synthesized photocatalysts. SEM micrographs showed agglomeration with a non-uniform distribution of particles, which is a characteristic of surfactant-free precipitation reactions in aqueous media. The Ag/AgBr photocatalyst exhibited the best degradation efficiency, resulting in 83.37% and 89.39% photodegradation after 5 h of UV and visible light irradiation, respectively. The effect of catalyst loading, initial solution pH, and 2,4-DCP concentration was investigated for the best-performing Ag/AgBr photocatalyst. The degradation kinetics were best described by the pseudo-first-order Langmuir–Hinshelwood model. The photocatalytic capacity of Ag/AgBr decreased by 50% after five reuse cycles. SEM images revealed heightened levels of photodegradation on the catalyst surface. The study proved the feasibility of using simple synthesis methods to produce visible light active photocatalysts capable of degrading refractory phenolic pollutants in aqueous systems.

Silver (Ag) doped graphitic carbon nitride (g-C3N4) photocatalyst for enhanced degradation of Ciprofloxacin (CIP) under visible light irradiation

Pharmaceutical industry wastewater is causing an increased risk of resistant pharmaceutical micropollutants (PMP) e.g. antibiotic resistant bacteria (super bug) in the ecosystem. Amongst variety of wastewater treatment approaches, Advanced oxidation processes (AOPs) employing photocatalysis provides a cost-effective and sustainable approach for fixation of PMP in an economical and efficient manner to counter the potential risks. Until today, tremendous efforts have been made to trig the performance of photocatalytic wastewater treatment, with the key focus on development of cost-effective, efficient and a moderately stable photocatalyst. Such attempts succeeded with different types of photocatalysts using different synthesis techniques. In recent years, graphitic carbon nitride (GCN) has emerged as one of the cost effective, moderately stable, nontoxic and efficient photocatalyst, and has been scarcely studied specifically for pharmaceutical micropollutants (PMPs) degradation. Hence, considering these factors alongside the facile synthesis and moderate optical absorption of GCN, an effort was made in the present work with effective customization of GCN i.e. silver (Ag) doping to extend light absorption in visible light range which may enhance the photocatalytic performance for Ciprofloxacin (CIP) degradation. The optimization of photocatalytic performance was executed with varied Ag dopant content to obtain an optimum sample with supreme photocatalytic activity for the maximum degradation of CIP, a common antibiotic. The best Ag-doped GCN sample (0.1 AGCN) exhibits a photocatalytic degradation efficiency of 84%, which is 2.15 times greater than pure GCN (39%). The obtained results showed that the strategy of Ag doping substantially enhances the photocatalytic performance, thus offering an efficient mean for developing visible light active photocatalyst for PMP removal and encouraging further research. The photocatalytic performance of the prepared samples was evaluated by degradation of CIP under visible light irradiation. Several characterization techniques were used to characterize and analyze the prepared samples, such as X-ray diffraction (XRD), Scanning electron microscopy (SEM), Raman spectroscopy, Fourier Transform Infrared (FTIR) spectroscopy, UV Visible absorption, and Photoluminescence (PL) spectroscopy.

Carbon nitride- and graphene-based materials for the photocatalytic degradation of emerging water pollutants

This review highlights several advantages and improvement strategies for carbon nitride as a visible light-active photocatalyst and graphene derivatives as a supporting material for the photocatalytic degradation of emerging water pollutants.

Solar light driven atomic and electronic transformations in a plasmonic Ni@NiO/NiCO3 photocatalyst revealed by ambient pressure X-ray photoelectron spectroscopy

This work employs ambient pressure X-ray photoelectron spectroscopy (APXPS) to delve into the atomic and electronic transformations of a core–shell Ni@NiO/NiCO3 photocatalyst – a model system for visible light active plasmonic photocatalysts used in water splitting for hydrogen production.

Synthesis of TiO2/Fe2O3 Nanocomposites as Photocatalyst for Methyl Orange Degradation

Fe2O3/TiO2 composites were successfully synthesized using the sol-gel method. The photocatalytic performance of prepared nanocomposites to degrade methyl orange under UV light irradiation was systematically investigated. The Fe2O3 added and calcination temperature were varied to study their effect on psychochemical properties. Further, to study the effect of psychochemical properties of the prepared nanocomposites on photocatalytic activity, X-ray diffraction (XRD), and scanning electron microscope Energy Dispersive X-ray spectroscopy (SEM-EDS) characterization were conducted. The visible light active Fe2O3 photocatalyst managed to decrease the bandgap energy of the prepared composites from 3.32 eV to 1.95 eV. This decrease in the band gap energy led to the composite being more active under visible light and less active under UV light irradiation. A composite with 6% Fe2O3 content exhibits the smallest degradation efficiency of 14% in 180 min, while the pure TiO2 nanoparticles are 94%. The results in this study provided important implications for further research on the preparation of composite TiO2 with Fe2O3 co-catalyst showing a promising route for improving the visible light activity of photocatalysts.

Graphene oxide-modified polythiophene nanohybrids: antibacterial properties and sonophotocatalytic degradation of dyes under visible-light irradiation

The present work highlights the synthesis of graphene oxide (GO) modified polythiophene (PTh) for its application as an antibacterial agent as well as a visible light active photocatalyst. PTh was synthesized via the interfacial polymerization method using FeCl3 as initiator and then formulated as nanohybrids by mixing it in different weight ratios with graphene oxide (GO) i.e., 1 wt.%,3 wt.% and 5 wt. %. PTh and GO/PTh nanohybrids were characterized using FTIR, UV-visible, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) techniques. The polymerization of PTh as well as modification of PTh with GO was confirmed by IR studies, while the shifting of electronic transitions of PTH upon modification with GO were confirmed by the UV-visible studies. The degradation of dyes, Alizarin Yellow (AY), Basic Blue (BB) and Congo Red (CR) was carried out via sonophotocatalysis under visible light using PTh and GO/PTh as catalysts for a period of 60 min. The GO/PTh revealed higher degradation efficiency as compared to PTh. To evaluate its effectiveness as an antibacterial agent against Bacillus subtilis, disk diffusion inhibitory assay was carried out under dark and light conditions. The results showed that PTh and GO/PTh nanohybrids had bactericidal properties, regardless of light exposure. The results of the minimal inhibitory concentration (MIC) assay indicated the nanohybrid of 3-GO/PTh had the lowest MIC, followed by 1-GO/PTh and 5-GO/PTh.

Visible Light Photocatalysis: Green Hydrogen Production

The next few decades will experience the convergence of diverse materials and scientific disciplines resulting in innovative products and processes for the benefit of mankind. If the proliferation of today’s technologies and the urgent need to address global climate change issues is any indication of the speed and power of changes in economies to be expected, a dramatic shift to sustainable technologies has to occur to provide cost-effective, low carbon footprint solutions. In this talk we will introduce about possible strategies based on fundamentals of physics and materials engineering that can potentially contribute to our efforts to preserve the planet’s environment at an acceptable level. Exploiting solar energy, as visible radiation constitutes a major share (~ 46%) of the solar spectrum, strategies for carbon reduction technologies can be devised. We have been working on the synergistic development of visible light active photocatalysts suitable for activating reactions by engineering nanomaterials and interfaces. Hydrogen production (H2) by Photocatalytic reactions is a promising process for green H2 generation as a fuel or an alternate energy source. Organic compounds like alcohols, polyols, sugars, as well as organic acids and lignocellulosic compounds can serve as sacrificial agents (electron donors) to reduce e−–h+ recombination leading to a more efficient process. Cellulose, the most abundant material on the earth that is a part of some of the waste generated by humans is a natural and carbon-neutral source as a sacrificial agent during photo-induced splitting of water for green H2 production and can be an attractive for building a sustainable system for photocatalytic H2 production. Some of these areas utilising visible light photocatalysis for oxidation of organic pollutant, microbe removal, anti-biofouling coatings and microplastic degradation will be briefly discussed.

Photo-Generated Charge Carrier Dynamics in Metal Oxide Photocatalysts

Solar water splitting is one of the most attractive energy carrier generation processes to utilize solar energy. Light generated hydrogen is a clean energy carrier, since their consumption for energy generation produces only water. Moreover, generated hydrogen can be stored and used whenever required. Hydrogen is mostly used as a feedstock in the chemical and petrochemical industries, e.g. production of ammonia, methanol and fertilisers.[1]The photocatalytic solar water splitting process has been studied extensively over the last half century. However, despite the efforts, no ideal photocatalyst has yet been identified to meet three main requirements for commercialisation: (1) low cost, (2) high solar to hydrogen (STH) efficiency and (3) durability. Over the last two decades, considerable efforts have focused on developing visible light active photocatalysts, and some promising photocatalysts with relatively high water splitting efficiency were discovered.[2] In contrast to search of appropriate photocatalyst (nano)materials, mechanisms of photocatalytic water splitting reactions, in particular charge carrier dynamics of photocatalysts, were little studied. Understanding charge carrier dynamics in photocatalysts will certainly provide an opportunity to design high efficiency photocatalysts.In this presentation, we will show dynamics of photo-generated charge carries in metal oxide photocatalyst by employing a series of transient absorption spectroscopies covering from 150 fs to 100 s over UV-VIS-NIR wavelength ranges.[2] Correlation of the charge carrier dynamics with photocatalysis reactions will be discussed.This work was partly supported by ARC DP fund (DP180103815) and ARC LIEF funds (LE170100235 and LE200100051), Australia, and the Collaborative Research Program of Institute for Chemical Research, Kyoto University (grant number 2023-45 and 2022-99), Japan. We also acknowledge supports from School of Engineering, RMIT University, and Forefront Research Center, Faculty of Science, Osaka University.

Solid state conversion of novel coordinated precursors to visible light active photocatalysts with enhanced photocatalytic activity

The new polydentate N'1,N'3‐bis((E)‐3‐oxopentan‐2‐ylidene)malonohidrazide chelating agent (H2L) and its coordinated complexes of Co2+, Cu2+, and Ni2+ were prepared and characterized by elemental analysis, molar conductance, and spectra (Fourier transform infrared [FT‐IR], ultraviolet–visible spectroscopy [UV–vis], and Fast‐Atom Bombardment Mass Spectrometry (FAB‐MS). Also, thermal and magnetic investigations were conducted. X‐ray single crystal of the H2L ligand revealed a triclinic structure with space group P‐1. In this study, we provide a one‐pot preparation approach for transition metal oxide nanoparticles (NPs) such as CuO, Co3O4, and NiO NPs. The methodology entails the thermal decomposition of coordinated metal precursors in a solid‐state environment, obviating the necessity for agitation and rinsing. The remarkable significance of this method lies in its ability to produce highly pure NPs without the requirement of washing, and it allows for systematic and efficient production. Herein, we propose a large‐scale, environmentally benign and renewable, transition metals oxide NPs such as CuO, Co3O4, and NiO using solid‐state thermal degradation of their coordinated precursors. The NPs are subjected to analysis employing a range of techniques, such as X‐ray powder diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), N2 sorpometry (BET), and UV–vis). The photocatalytic activities of the synthesized NPs were assessed using photodegradation of organic contaminants in wastewater.

Design and synthesis of Fe2WO6/Eu-doped BiOBr nanocomposite: A novel 0D/2D Z-scheme heterojunction system for simultaneous boosted visible-light driven photocatalytic bisphenol A degradation and Cr(VI) reduction

Increasing flux of noxious organics and heavy metals emitted by industrial effluents into surface water bodies have been terrifying the ecology in recent years. Herein, we have designed new Z-scheme 0D/2D Fe2WO6/Eu-doped BiOBr (FW/Eu-BOB) nanocomposites for efficient simultaneous visible light decomposition of two endocrine disruptors, namely bisphenol A (BPA) and hexavalent chromium (Cr(VI)). The successful nanocomposite fabrication was validated via crystallography and spectroscopic analyses, whereas the morphologic traits were testified via microscopy studies. Compared to single-phase component samples, 15-FW/2Eu-BOB nanocomposite displayed enhanced photoactivity, which completely eradicated both BPA and Cr(VI) after 50 min of visible light irradiation. The ameliorated photoactivity was ascribed to the Z-scheme electron transfer between FW and Eu-BOB, and its expedition of charge separation was proven by optoelectronic analyses. Furthermore, the 15-FW/2Eu-BOB nanocomposite showed good adaptability in a broad pH range, resistance to co-existing interfering substances and great durability after multiple runs. The real-world viability of 15-FW/2Eu-BOB photocatalysis was also tested via the real printed ink effluent-containing BPA and Cr(VI) treatment. Moreover, the phytotoxicity tests presented that the photocatalytically treated effluent promoted the germination of Vigna unguiculata which shown its environmentally friendly for practical uses. The hydroxyl radical and photogenerated electron were proven to be dominant reactive species in photocatalytic reaction. This study offers a new insight for designing highly efficient visible light-active photocatalysts toward eradicating multifarious pollutants in effluent.