rGO Nanocomposite Research Articles

Exploring the structural, optical, magnetic, and antibacterial characteristics of hydrothermally synthesized α-Fe2O3/rGO nanocomposites

Abstract Hematite (α-Fe2O3) and its composites have garnered significant interest due to their outstanding features, making them promising candidates for a wide range of applications in photocatalysis, water splitting, gas sensing, and antibacterial fields. This study describes the synthesis of hematite and reduced graphene oxide (rGO) nanocomposites via a facile hydrothermal method, producing three samples using 0.018 g (FG1), 0.036 g (FG2), and 0.072 g (FG3) of graphene oxide (GO). The prepared nanopowders were subjected to versatile characterizations for studying their morphological, structural, optical, and magnetic characteristics. The growth of the rhombohedral structure of hematite was confirmed by analyzing x-ray diffraction patterns, and the production of nanocomposites was verified by Raman and infrared spectroscopy. According to electron microscope images, increasing the content of GO in the precursor solution caused the change of the morphology from large rhombus and cubic shapes with sizes of about 180 nm to worm-like nanoparticles with a length of about 90 nm and a mean diameter of 25 nm. The magnetic hysteresis loops of the composite samples reflect their ferromagnetic characteristics, with saturation magnetization (Ms) values of 0.02235, 0.14990, and 0.0608 emu g−1 for FG1, FG2, and FG3 samples, respectively. Lastly, the antibacterial activity of the nanocomposites was screened against both Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative) bacteria, and the results indicated that the growth of both bacterial strains was inhibited by all synthesized nanoparticles.

Development of rare earth doped SiO2/rGO from rice husk for antioxidant, photocatalysis, electrochemical and sensor studies

The present work determines the synthesis of cerium loaded silicon dioxide (Ce-SiO2/rGO) nanocomposite by using reflux method. The Ce-SiO2/rGO was confirmed by using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive (EDAX) techniques. In photodecomposition investigation, Rose Bengal (RB) dye was degraded efficiently using Ce-SiO2/rGO nanocomposite (95 %) at 150 min with follows first order kinetics. The antioxidant property against 2,2-diphenyl-1-picrylhydrazyl (DPPH) was found to be 98 % performance with IC50 value of 488.35 mg/mL. The super capacitance value of Ce-SiO2/rGO was increased compared to that of rGO, SiO2 and SiO2/rGO respectively. The electrochemical reversibility (EO−ER) and diffusion coefficient (D) values were determined using 1 M KCl by cyclic voltammetry method. Ce-SiO2/rGO nanocomposite was used as an electrochemical sensor to detect bee pollen and cow urine. The produced material has superior dye purification, redox behavior, bio-molecule detection, and antioxidative capabilities.

SnO2-TiO2/reduced graphene oxide nanocomposites: Green synthesis and enhanced photocatalytic efficiency for dye removal

Titanium oxide nanoparticles (TiO2 NPs) have been interested in potential applications, including gas-sensing, energy storage, environmental remediation, and medical fields. In the present work, fabricated SnO2-TiO2/RGO nanocomposites (NCs) have been produced through a green precipitation approach. XRD, TEM, SEM, EDX, XPS, FTIR, UV, and PL analyses have been carefully applied to invistage the physicochemical properties of prepared NPs and NCs. The XRD data showed that the crystal structure of the TiO2 NPs was affected by the introduction of SnO2 NPs and RGO sheets. The spherical shape of the prepared samples and their morphologies were confirmed using TEM and SEM images. EDX and XPS analyses confirmed that tin (Sn), titanium (Ti), oxygen (O), and carbon (C) were further present in the SnO2-TiO2/RGO NCs. FT-IR spectra determines the functional groups with bands between the compositions of obtained NPs and NCs. Besides, the band gap energies of prepares samples were estimated from UV–vis spectra. It displayed that the absorption peak of the synthesized TiO2 NPs was improved after the addition of SnO2 NPs and an RGO sheet. PL analysis indicate that the PL intensity of the prepared TiO2 NPs was decreased with the addition of SnO2 NPs and RGO sheets due to a decrease in the recombination rate of electrons (e−)-holes (h+). As shown in photocatalytic results, the photodegradation of methylene blue (MB) dye of SnO2-TiO2/RGO NCs was reached 92.20% after 140 min of UV irradiation. These results suggest that the addition of RGO sheets occupied a role in enhanced the photocatalytic performance of the prepared NCs. This study highlighted that these samples could be applied in various applications such as photocatalytic and therapeutic areas.

Enhanced photocatalytic and supercapacitor performance of CeO2 nano foam integrated MWCNT and rGO nanocomposites

In this study, Cerium oxide nanoparticles (CeO2 NPs) with foam like morphology were prepared using the Moringa Oleifera seed extract-assisted green synthesis method. The prepared CeO2 NPs were integrated respectively with reduced graphene oxide (CeO2/rGO) and multi-walled carbon nanotubes (CeO2/MWCNT) via a simple one-pot reflex method. The structural and morphological features and elemental characteristics, including the physico-chemical and thermal characteristics of the samples, were assessed. The photocatalytic degradation ability of the catalyst was tested against Alizarin Red (AR) and Safranin (SF) dyes. Under sunlight, degradation efficiencies of 92.62%, 95.46%, and 99.62% were achieved against Safranin dye by CeO2, CeO2/MWCNT, and CeO2/rGO, respectively. The XRD analysis shows the structural phase stability of the nanocatalyst even after five cycles. The supercapacitor characteristics of all anode electrode samples were assessed. Moreover, the specific capacitance values of 370, 413, and 554 Fg-1 were measured using cyclic voltammetry at a scan rate of 5 mV/s for CeO2, CeO2/MWCNT, and CeO2/rGO, respectively. After undergoing 3000 charge-discharge cycles, the hybrid CeO2/rGO nanocomposite revealed admirable cycling stability with an 8.6% decrease in its specific capacitance. According to the results, the green-mediated CeO2/rGO heterojunction nano semiconducting materials are promising candidates for twin applications in photocatalysis and supercapacitors.

Fabrication of a Two-Dimensional Heterostructured MoS2-RGO Nanocomposite for Enhanced Photocatalytic Hydrogen Evolution

Fabrication of a Two-Dimensional Heterostructured MoS₂-RGO Nanocomposite for Enhanced Photocatalytic Hydrogen Evolution

Combined influence of vanadium doping and rGO composite partnering on the photocatalytic ability of TiO2

Nowadays, the presence of noxious organic azo dye molecules in the industrial effluents is a pervasive and significant global concern as it severely affects both human and ecological well-being. In this context, vanadium-doped titanium oxide/reduced graphene oxide (TiO2:V)/rGO nanocomposite was prepared using a soft-chemical method using Cassia fistula fruit pulp extract via green synthesis and its photocatalytic dye degradation ability was investigated against a cationic (Rhodamine-B (Rh-B)) and an anionic (Eosin Yellow (EY)) dye. The nanocomposite exhibits superior dye degrading efficiency of 95% and 97% for Rh-B and EY, respectively compared to TiO2, TiO2:V, and rGO. The structural, morphological and surface elemental composition results confirm the formation of the nanocomposite. This nanocomposite TiO2:V/rGO can be used as a heterojunction photocatalyst for cost-effective dye waste removal and commercial dye detoxification processes.

Effect of rGO on photocatalytic performance of Fe2O3-ZnO/rGO nanocomposite

The methods of removing various pollutants from water, due to the limitation of drinking water resources and also the increase in the production of pollutants from various industries, have been widely considered. A green technique that has emerged as a promising process in the degradation of numerous organic pollutants from water is the photocatalytic process. Here, Fe2O3-ZnO/rGO nanocomposites with 0.5, 1, 2 mass percentages of rGO nanosheets were successfully fabricated. These nanocomposites have been characterized by XRD analysis, FESEM, Raman spectroscopy and UV-vis spectrophotometer. Next, the photocatalytic activity of Fe2O3-ZnO/rGO nanocomposites in removing RhB dye was studied. Fe2O3-ZnO/1% rGO nanocomposite showed the best photocatalytic performance with a degradation percentage of 100% in 180 min with a rate constant of 0.020 min−1 and a half-life of 34.7 min. Finally, this optimal photocatalytic activity was attributed to the smaller optical gap of this nanocomposite.

Physical and biological characteristics of electrospun poly (vinyl alcohol) and reduced graphene oxide nanofibrous structure

The fabrication of graphene-based nanocomposites has been a topic of increasing interest due to graphene’s exceptional physical properties and the ability to enhance the properties of various polymeric materials. Evaluating the biocompatibility of these nanocomposites is crucial to ensure their safe and effective use in biomedical applications. This study characterized and assessed the biocompatibility of previously fabricated electrospun polyvinyl alcohol (PVA)/reduced graphene oxide rGO fibrous structures by conducting a comprehensive assessment of their physical and biological characteristics. Contact angle measurements revealed that adding rGO to electrospun PVA fibers enhanced the surface wettability, improving the fibrous structure’s PBS absorption capacity and degradation behavior. Including the rGO content resulted in a higher water vapor transmission rate, reaching ∼48 g/m2·day for PVA + 0.5 wt.% rGO and ∼45 g/m2·day for PVA + 1.0 wt.% rGO, compared to ∼40 g/m2·day for electrospun PVA fibers. Cell culture studies, including MTT assay, alkaline phosphatase (ALP) activity analysis, alizarin red staining, fluorescence microscopy, and SEM analyses, demonstrated that electrospun PVA + 1.0 wt.% rGO nanocomposites exhibited superior cell viability, proliferation, and growth compared to other samples, due to the improved physical properties of the PVA + 1.0 wt.% rGO fibrous structure.

Facile synthesis and first principles calculations of Li-MoS2/rGO nanocomposite for high-performance supercapacitor applications

Two-dimensional (2D) nanostructured materials such as graphene oxide nanosheets and molybdenum disulfide (MoS2) are potential candidates for electrochemical energy storage applications. The layered structure of MoS2 makes it a promising active electrode material for supercapacitors. Lithium (Li) interacted with MoS2/reduced graphene oxide (Li-MoS2/rGO) nanocomposite has been synthesized in two steps using a sonochemical dispersion method, and a one-pot hydrothermal method resulting in few-layered MoS2/rGO nanosheets of 2D heterointerfaces. The Li-MoS2/rGO nanocomposite exhibits a high specific capacitance of 173.3 F g−1 at a current density of 1 A g−1. Furthermore, an asymmetric supercapacitor device fabricated with Li-MoS2/rGO achieves a good energy density of 10.6 Wh kg−1 at a power density of 686.3 W kg−1 and outstanding cycling stability with 81.2 % capacity retention over 10,000 cycles. The dispersion of 2D-MoS2 in water is due to the strong electrostatic interface. The structural and electronic properties are theoretically calculated for pristine and Li-interacted MoS2/rGO heterostructure using density functional theory. A comparison of the density of states plots of the two heterostructures and the difference charge density plot of Li-MoS2/rGO heterostructure clearly brings out the importance of the presence of Li. A value of 64 μF cm−2 for the quantum capacitance for pristine MoS2/graphene heterostructure increases to a value 99 μF cm−2 corroborating the experimental observations and we assign this change to the transfer of charge from the Li atom to the outer S atoms in the MoS2/graphene heterostructure. This comprehensive approach, combining experimental synthesis with computational modelling, significantly advances the development and optimization of high-performance supercapacitor materials in the energy storage field. The Li-MoS2/rGO nanocomposite has excellent electrochemical specific capacitance and long-term cyclic stability and has been effectively used for supercapacitor applications with high electrochemical performance.

Synthesis and Characterization of Synergetic Pd/MoO3–rGO Hybrid Material as Efficient Electrode for Supercapacitor Application

In this work, study synthesized Pd–rGO and Pd/MoO3–rGO nanocomposites via a one-pot hydrothermal method, serving as efficient electrodes for supercapacitor applications. Various analytical techniques, including XRD, XPS, HRTEM, BET, and Raman spectroscopy, were employed to characterize the structural, morphological, and physiochemical properties to assess the electrochemical supercapacitor performance of nanocomposite materials. The analyses confirmed that the charge transfer mechanism between the MoO3-NR with Pd-rGO in Pd/MoO3–rGO samples has significantly improved the electrochemical performance of Pd/MoO3–rGO by 2.7 times compared to Pd-rGO sample (105.00 F/g at 0.5 A/g). Remarkably, the Pd/MoO3–rGO hybrid material exhibited excellent electrochemical activity, boosting a specific capacitance of 291.50 F/g at a current density of 0.5 A/g, accompanied by energy density and power density values of 18.06 Wh/kg and 250.00 W/kg, respectively. Furthermore, it demonstrated noteworthy stability over prolonged usage, retaining 88.46% of its capacity after 1,000 cycles at a constant current density of 1.0 A/g. These findings underscore the promising potential of the Pd/MoO3–rGO nanocomposite as a highly effective electrode material for supercapacitors.

A Novel Co-MoS2/RGO-Based Highly Sensitive Sensor for Simultaneous Detection of Ascorbic Acid and Uric Acid

This study presents the synthesis of cobalt-doped MoS₂/reduced graphene oxide (Co-MoS₂/RGO) nanocomposites via a microwave-assisted technique. These nanocomposites were meticulously characterized, revealing intricate details of their nanostructure and surface morphology. Electrochemical analyses demonstrated distinct sensing mechanisms for the electrochemical oxidation of ascorbic acid (AA) and uric acid (UA) at the Co-MoS₂/RGO interface. The sensor exhibited a diffusion-controlled behavior, achieving remarkable detection limits of 0.013 μM for AA, 0.06 μM for UA, 0.248 μM for AA in the presence of UA, and 0.36 μM for UA in the presence of AA. Additionally, the Co-MoS₂/RGO composite demonstrated impressive individual and selective sensitivities for AA, measuring 8.42 μA μM−1 cm−2 and 2.786 μA μM−1 cm−2, respectively, and for UA, measuring 10.628 μA μM−1 cm−2 and 7.25 μA μM−1 cm−2, respectively. These results highlight the exceptional capability of the Co-MoS₂/RGO nanocomposite to distinguish and accurately quantify concentrations of AA and UA, both individually and simultaneously. Furthermore, the Co-MoS₂/RGO sensor demonstrated outstanding repeatability and reproducibility, consistently delivering high performance even after 15 days. These findings underscore the potential of the Co-MoS₂/RGO-based electrochemical sensor as an ultra-sensitive, highly selective, and dependable tool for real-time sample analysis in practical applications.

Ag2O/ZnO/CuO and Ag2O/ZnO/NiO immobilised on reduced graphene oxide: synthesis, characteristics and its adsorption, catalytic behaviour and antibacterial activities

ABSTRACT Ag2O/ZnO/CuO (A/Z/C) and Ag2O/ZnO/NiO (A/Z/N) nanometal oxides were synthesised in different rations by co-precipitation method and were immobilised on reduced graphene oxide (rGO). The prepared nanocomposites were characterised by Fourier transform infrared spectroscopy (FTIR), Raman spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). Their application in the adsorption of MB, RhB and MO dyes, olefin oxidation and antibacterial properties were investigated. The results showed that A/Z/N/rGO adsorbent has 99% (10 min), 93% (20 min) and 97% (12 min) adsorption of MB, RhB and MO, respectively. From the investigation of Freundlich and Langmuir models, it was found that the adsorbent follows Langmuir. Moreover, the reaction thermodynamics was also studied, the reaction was endothermic and spontaneous. The kinetics of dye adsorption MB, RhB and MO on the surface follow a pseudo-second order model. At optimum condition, the conversion and selectivity of α-methylstyrene to acetophenone was >99% by A/Z/N and A/Z/C catalysts. A/Z/C/rGO nanocomposite has good antibacterial properties against two bacteria E. coli and S. aureus.

Development and fabrication of graphene oxide and reduced graphene oxide incorporated MnFe2O4@Bi2WO6 nanocomposite for efficient degradation of antibiotic drug as water contaminant under visible-light illumination

Tetracyclines are one category of extensively applied antibiotics. Meantime, owing to misapplication and inappropriate disposal, they are mostly discovered in wastewater, which causes a series of environmental contamination and stated a threat to a person's health and security. The present study investigates the photodegradation of tetracycline using MnFe2O4@Bi2WO6/graphene oxide, GO, and MnFe2O4@Bi2WO6/reduced graphene oxide, RGO, and MnFe2O4@Bi2WO6 nanocomposites as permanent photocatalyst with the aid of visible light. A facile microwave assisted combustion method was applied in solid state rapidly, conveniently to fabricate MnFe2O4@ Bi2WO6–GO and MnFe2O4@ Bi2WO6–rGO nanocomposites at low power 150 W and in time 10 min with very low amount of glycine (as fuel). Consequently, XRD, EDX Mapping, DRS, PL, TEM, FESEM, FTIR, VSM, BET and UV–Visible spectrophotometric analysis demonstrated characteristic of nanocomposites and specifications of existent photocatalyst. Magnetic investigations revealed that the MnFe2O4@ Bi2WO6-GO and MnFe2O4@ Bi2WO6–RGO nanocomposites can be easily separated from the solution by an external magnetic field. MnFe2O4@ Bi2WO6–GO nanocomposites were discovered with high specific surface area 73.83 m2/g than MnFe2O4@Bi2WO6–RGO nanocomposites with specific surface area 17.75 m2/g. Highest photocatalytic activity was determined for the MnFe2O4@ Bi2WO6–GO (catalyst-0.10 g/l, tetracycline antibiotic concentration 10 mg/l and at pH = 4) within 25 min of visible light irradiation without using any oxidizing agent. The investigation of kinetic study revealed that kinetic parameter specified to photodegradation and experimental outcomes follow first-order model. the superoxide, hydroxyl radicals, ℎ+ holes and light are the principal demonstrates of the reaction mechanism for the effective degradation of tetracycline drug. The evaluation of MnFe2O4@ Bi2WO6–GO and MnFe2O4@ Bi2WO6–RGO magnetic catalysts has proposed the encouraging and significant role of nanocomposites in perilous pharmaceuticals refinement from industrial wastewater and also, magnetically photocatalyst attributes can be used as a potent separable tool for eliminating water pollution problems in the various industry.

Optical and electric properties of tin oxide (SnO2) with reduced graphene oxide nanocomposite thin films

Due to their superior properties, two-dimensional (2D) nanomaterial materials have become increasingly popular for enhancing SnO2 thin films. In the paper, a thermionic vacuum arc (TVA) deposition system was used to produce a thin film of SnO2 with a reduced graphene oxide (rGO) nanocomposite. SnO2 thin films have become widely used in sensor applications, and these sensors have been shown to work at relatively high temperatures compared to room-temperature semiconductors. As a result, working temperatures affect the material properties. The surface properties of the deposited and post-annealed samples were investigated using field emission scanning electron microscopy integrated with energy dispersive x-ray spectroscopy and atomic force microscopy. The weight ratios of carbon and tin were calculated as 35 % and 65 %, respectively. The mean Z-height of the nanoparticles was determined to be 9 nm, and the distribution of the surface grains is nearly homogeneous. Following the post-annealing process, the thin film's band gap energy decreased from 3.78 eV to 3.25 eV. According to the photoluminescence spectra, emission peaks at 393 nm, 406 nm, and 443 nm were measured. The transmittance spectra of the various post-annealed samples at 150 °C were recorded, and they remained nearly the same. This consistency is a beneficial property of the thin film because SnO2:rGO nanocomposite thin films are designed to operate at relatively high temperatures. The present study investigates the advantages and properties of the post-annealed (repeating annealing) SnO2: rGO thin film.

Cu3(HHTP)2 decorated over rGO nanocomposites for flexible NH3 and H2S dual sensing at room temperature

Ammonia (NH3) and hydrogen sulfide (H2S) are both poisonous and corrosive gases, and timely detecting their leakage is thus required. Ideally, employing individual flexible sensor to simultaneously detect NH3 and H2S dual gases at room temperature would contribute to their miniaturization and integration, however, remains challenging. Here, flexible NH3 and H2S dual sensing at room temperature has been developed by utilizing Cu3(HHTP)2 decorated over reduced graphene oxide nanocomposites {Cu3(HHTP)2//rGO NCPs, HHTP=2,3,6,7,10,11-hexahydroxytriphenylene}, which have been synthesized via oxidation–reduction reaction of GO and Cu3(HHTP)2 metal–organic frameworks (MOFs). Typically, the Cu3(HHTP)2 MOFs are observed with spiny surface, and as-synthesized Cu3(HHTP)2//rGO NCPs present amorphous crystallization. Beneficially, Cu3(HHTP)2//rGO NCPs exhibit the NH3 and H2S dual sensing with the resistance-increasing response toward 10–50000 ppm NH3 and resistance-decreasing response to 0.1–20 ppm H2S. Further, the sensor prototype shows 40 days-long stability and 75 % high relative humidity tolerance, respectively. Remarkably, the ternary-NCPs show excellent flexibility, along with excellent sensing performance against various bendings. Theoretically, rGO with high specific surface ratio and Cu3(HHTP)2 MOFs with enriched adoption sites might contribute to NH3 and H2S diffusion and adsorption. Practically, the simulation utilizing Cu3(HHTP)2//rGO NCPs to monitor H2S and NH3 has been conducted with reliable sensing.

Explorations of physicochemical, photodegradation, phototoxicity, and kinetics of Bi2-2xCoxCdxO3/rGO nanocomposites for wastewater treatment applications

In recent times, there has been a pressing need to discover or manufacture a unique material that can serve as a photocatalyst for organic pollutants that are incapable of degradation. Pure Bi2O3 and Co, Cd co-doped Bi2-2xCoxCdxO3 (x = 0.8) nanoparticles were synthesized using the chemical co-precipitation method, but the new approach involves fabricating 10 % reduced graphene oxide Bi2-2xCoxCdxO3/rGO nanocomposites via the ultra-sonication route. This study investigated the effects of Co, Cd, and r-GO doping on the optical, electrochemical, structural, and photocatalytic properties of bismuth oxide. The synthesized nanomaterials were analyzed using X-ray diffraction (XRD), cyclic voltammetry, ultraviolet–visible (UV–Vis), Fourier transform infrared (FTIR), photoluminescence (PL), and Raman spectroscopy. The XRD patterns showed the formation of a monophasic monoclinic structure belonging to space group P21/c, with an average crystallite size estimated around 22–41 nm. According to the UV–visible study, the bandgap energy of Bi2O3 NPs, Bi2-2xCoxCdxO3 NPs, and Bi2-2xCoxCdxO3/rGO nanocomposites were 2.64 eV, 2.37 eV and 2.06eV respectively. The cyclic voltammetry technique was used to evaluate the functioning electrodes. In contrast to un-doped Bi2O3, the synergistic effects of Co, Cd, and r-GO on the substituted material increased the specific capacitance. The pure Bi2O3, doped Bi2-2xCoxCdxO3, and Bi2-2xCoxCdxO3/rGO photocatalyst degraded 62 %, 85 %, and 95.4 % respectively of RB-5 dye after 105 min of sunlight. The phytotoxicity analysis examined the germination of Hordeum vulgare seeds in treated and untreated RB-5 dyes. Additionally, scavenging investigations using reactive species trapping to confirm the dominant reactive species were evaluated. Bi2-2xCoxCdxO3/rGO nanocomposites are better at photocatalysis and have a narrow bandgap, which makes them useful as solar-active photocatalysts for getting rid of dyes in wastewater. In future, their composites with conducting polymers may improve their electrochemical and photocatalytic behaviour as well.

Fabrication of dual-functional smart materials: 2D-WO3/rGO nanocomposite for electrochemical detection and photocatalytic degradation of tetracycline

The extensive utilization of the antibacterial agent tetracycline (TC) in pharmaceuticals and livestock farming has sparked considerable health apprehensions for the welfare of both animals and humans. The presence of TC drug residues in soil, rivers, lakes, and groundwater further exacerbates these concerns. To address these issues, we synthesized WO3/rGO nanocomposites using a simple hydrothermal method and explored their bifunctional catalyst properties for the first time. These nanocomposites were investigated for their potential applications in electrochemical sensing and photocatalytic degradation of TC drug. The electrocatalytic oxidation of TC drug using the WO3/rGO/Glassy Carbon Electrode (GCE) nanocomposites demonstrated good sensitivity, low detection limit, low quantification limit and wide linear range of 1.708 µA µM−1 cm−2, 202 nM, 0.202 µM and 0.1–400 µM, respectively. Moreover, we assessed the WO3/rGO/GCE nanocomposites effectiveness in detecting TC drug in real samples, including milk, lake water, fish, and tap water, and found the recovery results to be satisfactory. Additionally, the nanocomposites displayed noteworthy photocatalytic activity in degrading the TC drug. The as-prepared WO3/rGO nanocomposites exhibited an impressive degradation efficiency of 87.5 % over 120 minutes under UV–visible light irradiation. Radical trapping tests confirmed that the *OH- radicals played a significant role in the degradation process. Our study highlights the outstanding electrochemical and photocatalytic properties of WO3/rGO nanocomposites, positioning them as highly promising materials for future biomedical and environmental applications.

Development of Potential Electrocatalyst: Highly Multiporous WO3–rGO Nanocomposites for Enhancing Electrocatalytic Oxygen Evolution Reactions

AbstractThe development of sustainable energy technologies, such as fuel cells and metal–air batteries, necessitates the use of a highly efficient electrocatalyst for the oxygen evolution process. The fabrication of WO3–rGO nanocomposites results in the formation of a multiporous nanostructure. The catalytic activity of highly multiporous WO3–rGO nanocomposites containing multiporous nanostructures is shown to be significant. The catalyst has the potential to facilitate highly reactive anodic oxygen reactions, hence augmenting the synergistic impact of interfacial charge transfer and the porous structure of WO3–rGO nanocomposites. The findings of this work indicate that the use of WO3–rGO nanocomposites as electrocatalysts exhibits a considerable overpotential value of 350 mV, a Tafel slope of 67 mV dec−1, good stability, roughness factor, and turnover frequency for the process of oxygen evolution in real‐world scenarios.

Effects of Heteroatom Doping on the Electrochemical Hydrogen Uptake and Release of Pd-Decorated Reduced Graphene Oxide.

Heteroatom doping has been widely recognized as a key strategy for improving the electrochemical properties of graphene-based materials for hydrogen storage. However, a precise understanding of how heteroatom doping influences catalytic performance, specifically regarding the intricate effects of doping-induced electron redistribution, has been lacking. Here, we report on a comprehensive exploration of the electrochemical performance enhancement in Pd-decorated reduced graphene oxide (rGO) nanocomposites through fluorine (F) or nitrogen (N) doping. Various analytical techniques such as scanning electron microscopy (SEM), transmission electron microscopy (TEM), energy-dispersive X-ray (EDX) spectroscopy, Raman spectroscopy, X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), X-ray absorption near edge structure (XANES), and extended X-ray absorption fine structure (EXAFS) were employed to thoroughly characterize the synthesized nanocomposites. The findings revealed that either F or N doping effectively addressed clustering issues of Pd nanoparticles formed on the rGO surface, resulting in improved homogeneity of Pd distribution. Electrochemical studies provided crucial insights into hydrogen adsorption-desorption behaviors. The heteroatom doped nanocomposites, Pd/N-rGO and Pd/F-rGO, exhibited superior electrochemical performance, which can be attributed to the increase of the active sites due to the N-/F-doping, respectively. The hydrogen discharge capacities of Pd/N-rGO (80.9 mAh g-1) and Pd/F-rGO (25.0 mAh g-1) nanocomposites were determined to be over 4.0 and 1.2 times higher than that of the Pd/rGO (20.1 mAh g-1), respectively. The distinctive electrochemical performances observed between the two types of heteroatom-containing nanocomposites highlight the subtle structural modifications of Pd nanoparticles as the key factor influencing performance. This research contributes essential knowledge to the evolving field of hydrogen storage materials, emphasizing the promising potential of heteroatom-doped Pd-decorated rGO nanocomposites for advancing clean and sustainable energy solutions.

Ag-Cu2O Supported Biomass-Derived rGO for Catalyzing Suzuki-Miyaura Cross-Coupling.

The search for cost-effective, efficient, and ecofriendly heterogeneous catalysts for the Suzuki-Miyaura reaction is crucial due to challenges with expensive, toxic homogeneous catalysts. This study centrally aims at crafting a pioneering green catalyst by adorning reduced graphene oxide (rGO), sourced from basil seeds (Ocimum basilicum L.), with an Ag-Cu2O composite structure. Comprehensive characterization of the Ag-Cu2O/rGO nanocomposite was conducted through FTIR, SEM, hHR-TEM, EDS, XPS, XRD, TGA, and N2 adsorption/desorption analyses. Results showed that nanosized Ag-Cu2O particles were partially integrated into rGO sheets derived from basil seeds, acting as active species for oxidative addition with aryl halides in the SMR. The catalytic efficacy of this robust nanocatalyst was assessed in Suzuki-Miyaura cross-coupling reactions, targeting the synthesis of biaryls employing various aryl halides and aryl boronic acids. The findings underscore that the Ag-Cu2O/rGO nanocatalyst manifests rapid reaction kinetics (15 min) alongside commendable yields (99%). The Ag-Cu2O/rGO demonstrates impressive recyclability, maintaining catalytic efficiency over four cycles. Utilizing it as a green substrate for metal loading highlights its potential, offering well-defined coordination sites. This approach facilitates stable heterogeneous catalyst fabrication, crucial for significant bond formations. Notable features include broad applicability, exceptional functional tolerance, scalability, and practicality. Moreover, it holds promise for automating safe processes and enabling efficient late-stage functionalization of complex molecules with moderate to high efficiency, presenting promising prospects for various applications in chemical synthesis.