Presence Of rGO Research Articles

Tailoring 3D-printed sensor properties with reduced-graphene oxide: improved conductive filaments.

Thedevelopment of a tailored filament is reportedcomposed of reduced graphene oxide (rGO) and carbon black (CB) in a polylactic acid (PLA) matrix and its use in the production of electrochemical sensors. The electrodes containing rGO showed superior performance when compared with those prepared in the absence of this material. Physicochemical and electrochemical characterizations of the electrodes showed the successful incorporation of both rGO and CB and an improved conductivity in the presence of rGO (lower resistance to charge transfer). As a proof-of-concept, the developed electrodes were applied tothe detection of the forensic analytes TNT and cocaine. The electrodes containing rGO presented a superior analytical performance for both TNT and cocaine detection, showing the lower limit of detection values (0.22 and 2.1µmol L-1, respectively) in comparison withpure CB-PLA electrodes (0.93 and 11.3µmol L-1, respectively). Besides, better-defined redox peaks were observed, especially for TNT, as well as increased sensitivity for both molecules.

Chitosan/Microcrystalline Cellulose Overlaid rGO/Fe3O4 Films: Broadband Dielectric Spectroscopy Investigations

Hybrid and straightforward inorganic/organic composites that can be used simultaneously for energy storage are reported. Films from chitosan (Cs) with microcrystalline cellulose (MCC) implanted with reduced graphene oxide (rGO) and/or magnetic Fe3O4 nanoparticles were fabricated. The reinforcement of the Cs/MCC films with rGO and /or Fe3O4 was studied through Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy with energy dispersive electron spectroscopy. In addition, their magnetic, conductivity, dielectric constant, and dielectric loss behaviors were studied. The magnetic investigations of the two films loaded with Fe3O4 have supper paramagnetic behavior. The saturation magnetization was decreased with the presence of rGO. At lower frequencies, the contribution of charge transport and interfacial polarization causes a sudden and nearly linear increase in permittivity with decreasing frequency. Unfortunately, no indication of electrode polarization was found, which reduces the ability of the prepared composition to store electrical energy. The electric modulus representation was employed to determine the relaxation time of the interfacial polarization quantitatively and numerically. No indication of electrode polarization was found.

Graphene-loaded nickel−vanadium bimetal oxides as hydrogen pumps to boost solid-state hydrogen storage kinetic performance of magnesium hydride

To modify the thermodynamics and kinetic performance of magnesium hydride (MgH2) for solid-state hydrogen storage, Ni3V2O8-rGO (rGO represents reduced graphene oxide) and Ni3V2O8 nanocomposites were prepared by hydrothermal and subsequent heat treatment. The beginning hydrogen desorption temperature of 7 wt.% Ni3V2O8-rGO modified MgH2 was reduced to 208 °C, while the additive-free MgH2 and 7 wt.% Ni3V2O8 doped MgH2 appeared to discharge hydrogen at 340 and 226 °C, respectively. A charging capacity of about 4.7 wt.% H2 for MgH2 + 7 wt.% Ni3V2O8-rGO was achieved at 125 °C in 10 min, while the dehydrogenated MgH2 took 60 min to absorb only 4.6 wt.% H2 at 215 °C. The microstructure analysis confirmed that the in-situ generated Mg2Ni/Mg2NiH4 and metallic V contributed significantly to the enhanced performance of MgH2. In addition, the presence of rGO in the MgH2 + 7 wt.% Ni3V2O8-rGO composite reduced particle aggregation tendency of Mg/MgH2, leading to improving the cyclic stability of MgH2 during 20 cycles.

Reduced Graphene Oxide Decorated Titanium Nitride Nanorod Array Electrodes for Electrochemical Applications

This work describes the fabrication and characterization of a new high surface area nanocomposite electrode containing reduced graphene oxide (rGO) and titanium nitride (TiN) for electrochemical applications. This approach involves electrochemically depositing rGO on a high surface area TiN nanorod array electrode to form a new nanocomposite electrode. The TiN nanorod array was first formed by the glancing angle deposition technique in a DC (Direct Current) sputtering system. GO flakes of ~1.5 μm in diameter, as confirmed by Dynamic Light Scattering (DLS), were electrodeposited on the nanostructured TiN electrode via the application of a fixed potential for one hour. The surface morphology of the as-prepared rGO/TiN electrode was evaluated by scanning electron microscopy (SEM) and the presence of rGO on TiN was confirmed by Raman Microscopy. The CV shows an increase in the capacitive current at rGO/TiN as compared to TiN. The rGO decorated TiN electrode was then used for analyzing the electrocatalytic oxidation of ascorbic acid and dopamine, and the reduction of nitrate by CV and linear sweep voltammetry (LSV), respectively. CV or LSV show that the electrochemical kinetics of these three analytes are significantly faster on rGO/TiN than TiN itself. Overall, the rGO/TiN electrode showed better electrochemical behavior for biomolecules like ascorbic acid and dopamine as well as another target analyte, nitrate ions, compared to TiN by itself.

Carboxymethyl-β-cyclodextrin functionalized TiO2@Fe3O4@RGO magnetic photocatalyst for efficient photocatalytic degradation of tetracycline under visible light irradiation

In this study, a novel magnetic photocatalyst, carboxymethyl-β-cyclodextrin functionalized titanium dioxide@Fe3O4@reduced graphene oxide (CMCD-TiO2@Fe3O4@RGO) was successfully fabricated by a facile hydrothermal synthesis method. Raman spectroscopy, XRD, BET, FT-IR, VGM, XPS, TGA, SEM, EDS and TEM were used to characterize the photocatalysts. The photocatalytic degradation behavior of tetracycline (TC) was investigated under 420 nm light wavelengths, and the reaction mechanism was interpreted. Furthermore, the stability and reusability of CMCD-TiO2@Fe3O4@RGO were assessed. The outcomes showed that CMCD-TiO2@Fe3O4@RGO possessed higher photocatalytic activity compared with TiO2@Fe3O4@RGO, TiO2@Fe3O4 and TiO2. Under continuous irradiation at 420 nm light for 60 minutes, CMCD-TiO2@Fe3O4@RGO achieved a TC degradation efficiency of 83.3 % at a concentration of 20 mg/L. The kinetic constant for the photocatalytic degradation of TC by CMCD-TiO2@Fe3O4@RGO was determined to be 0.459 mg L−1·min−1, which was 1.49 times higher than that of TiO2@Fe3O4. The main reactive oxygen species contributing to TC degradation were determined to be ·O2- and h+. The presence of RGO and CMCD is beneficial for the adsorption of TC on the photocatalyst. Furthermore, the transfer of photo-generated electrons from the semiconductor to the RGO suppresses electron-hole recombination and enhances carrier lifetime, thereby improving photocatalytic degradation efficiency. Remarkable recyclability and stability were observed in CMCD-TiO2@Fe3O4@RGO, with only a 10.4 % reduction in TC removal after five cycles.

Light-Responsive and Antibacterial Graphenic Materials as a Holistic Approach to Tissue Engineering.

While the continuous development of advanced bioprinting technologies is under fervent study, enhancing the regenerative potential of hydrogel-based constructs using external stimuli for wound dressing has yet to be tackled. Fibroblasts play a significant role in wound healing and tissue implants at different stages, including extracellular matrix production, collagen synthesis, and wound and tissue remodeling. This study explores the synergistic interplay between photothermal activity and nanomaterial-mediated cell proliferation. The use of different graphene-based materials (GBM) in the development of photoactive bioinks is investigated. In particular, we report the creation of a skin-inspired dressing for wound healing and regenerative medicine. Three distinct GBM, namely, graphene oxide (GO), reduced graphene oxide (rGO), and graphene platelets (GP), were rigorously characterized, and their photothermal capabilities were elucidated. Our investigations revealed that rGO exhibited the highest photothermal efficiency and antibacterial properties when irradiated, even at a concentration as low as 0.05 mg/mL, without compromising human fibroblast viability. Alginate-based bioinks alongside human fibroblasts were employed for the bioprinting with rGO. The scaffold did not affect the survival of fibroblasts for 3 days after bioprinting, as cell viability was not affected. Remarkably, the inclusion of rGO did not compromise the printability of the hydrogel, ensuring the successful fabrication of complex constructs. Furthermore, the presence of rGO in the final scaffold continued to provide the benefits of photothermal antimicrobial therapy without detrimentally affecting fibroblast growth. This outcome underscores the potential of rGO-enhanced hydrogels in tissue engineering and regenerative medicine applications. Our findings hold promise for developing game-changer strategies in 4D bioprinting to create smart and functional tissue constructs with high fibroblast proliferation and promising therapeutic capabilities in drug delivery and bactericidal skin-inspired dressings.

Interface engineering of composite systems: Focusing on the compatibility of reduced graphene oxide and Bi0.8La0.1Ba0.1Fe0.9Ti0.1O3 hybrid systems

The composite of reduced graphene oxide and perovskite-based ferroelectric materials offers exciting opportunities to enhance the optical performance of optoelectronic devices. The present work reporting rGO modified x(Bi0.8La0.1Ba0.1Fe0.9Ti0.1O3)-1-x(rGO) (La-BBFT/rGO) composite to investigate their structural, morphological, electrical, magnetic and optical properties by using robust solid-state and spun calcination method. X-Ray diffraction patterns confirm the rhombohedral crystal structure with space group (R3c) of both samples with the presence of rGO as second phase. The functional groups present in reduced graphene oxide (rGO) can act as nucleation sites for crystallization, leading to the formation of more grains and Grain boundaries. The ferroelectric phase transition was observed in La-BBFT/rGO composites at comparatively low temperature near 250 °C. The impedance spectroscopy confirms the non-Debye behaviour of relaxation process. The electric and magnetic remanence shows the compatibility of the switching state. Additionally, the optical band gap energy of both samples was evaluated and found to be in the range of 2.0 to 1.9eV. Incorporation of rGO in La-BBFT/rGO, were marginally improved, the dialectic, impedance, and optical properties, which could be beneficial for electronic and optical components in the opto-electronic industries.

Antibacterial wound dressing with cross-linked electrospun surface from reduced graphene oxide doped polyvinyl alcohol/sodium caseinate blends.

In this study, a new biomaterial with polyvinyl alcohol (PVA)/sodium caseinate (SodCa)/reduced graphene oxide (rGO) structure was developed. Antibacterial effective nanofibers were successfully produced by electrospinning method from 1%, 3%, 5%, and 7% rGO added PVA/SodCa (60:40, w:w) solution mixtures prepared for use as modern wound dressings. To create a usage area, especially in exuding wounds, hydrophilic PVA/SodCa/rGO electrospun mats were cross-linked by dipping them in a glutaraldehyde (GLA) bath. The surface micrographs of all nanofibers were homogeneous and smooth. rGO-doped biomaterials were obtained as thin nanofibers in the range of 301-348 nm. Nanofibers, which were completely soluble in water, after cross-linking preserved their existence in the range of 87%-81% at the end of the 24th hour in distilled water. It was reported that these biomaterials that persist in an aqueous environment show swelling behavior in the range of 275%-608%. The porosity of uncross-linked pure PVA/SodCa nanofibers increased by 46.75% after cross-linking. Moreover, the tensile strength of cross-linked PVA/SodCa electrospun mats increased in the presence of rGO. Provided that wound dressing is done every 24 h with 3% rGO-doped PVA/SodCa nanofiber and provided that wound dressing is done every 48 h with 5% rGO-doped PVA/SodCa nanofiber showed antibacterial activity against S. aureus as 99.38% and 99.55%, respectively.

Construction of SnO2/SnS2 n-n heterojunction anchored on rGO for synergistically enhanced low temperature formaldehyde sensing performance

Creating metal oxide heterostructures is a promising way to enhance sensing performance by modulating their electronic properties. Herein, SnO2/SnS2 n-n heterojunction anchored on rGO (3.84 % of SnS2) was constructed using a hydrothermal route and fabricated as sensors for detecting formaldehyde (HCHO). The response value of the SnO2/SnS2/rGO sensor is 8.91 to 10 ppm HCHO (100 °C), which is about 2.6 and 1.8 times higher than that of the SnO2 and SnO2/SnS2 sensor (200 °C), respectively. The SnO2/SnS2/rGO sensor is also sensitive to ppb level HCHO (1.33 to 100 ppb), exhibits fast response/recovery speed, good reproducibility and long-term stability, and remarkable selectivity. The significant enhancement performance of the SnO2/SnS2/rGO sensor could be ascribed to the synergistic effect of the n-n heterojunction between SnO2 and SnS2, as well as the presence of rGO, which acts as a charge carrier facilitator and enhances the specific surface area boost the high sensing properties. This work provides a practical approach to synthesizing hybrid materials with adjustable micro-morphology, and a promising strategy for designing HCHO sensors with high sensing performance.

Bidirectional enhancement of Li2S redox reaction by NiSe2/CoSe2-rGO heterostructured bi-functional catalysts

The high activity barriers of Li2S nucleation and deposition limit the redox reaction kinetics of lithium polysulfides (LiPSs), meanwhile, the significant shuttle effect of LiPSs hampers the advancement of Li-S batteries (LSBs). In this work, a NiSe2/CoSe2-rGO (NiSe2/CoSe2-G) sulfur host with bifunctional catalytic activity was prepared through a hard template method. Electrochemical experiment results confirm that the combination of NiSe2 and CoSe2 not only facilitates the bidirectional catalytic function during charge and discharge processes, but also increases the active sites toward LiPSs adsorption. Simultaneously, the highly conductive rGO network enhances the electronic conductivity of NiSe2/CoSe2-G/S and provides convenience for loading NiSe2/CoSe2 catalysts. Benefitting from the exceptional catalytic-adsorption capability of NiSe2/CoSe2 and the presence of rGO, the NiSe2/CoSe2-G/S electrode exhibits excellent electrochemical properties. At 1C, it demonstrates a low capacity attenuation of 0.087 % per cycle during 500 cycles. The electrode can maintain a discharge capacity of 927 mAh/g at a sulfur loading of 3.3 mg cm−2. The bidirectional catalytic activity of NiSe2/CoSe2-G offers a prospective approach to expedite the redox reactions of active S, meanwhile, this work also offers an ideal approach for designing efficient S hosts for LSBs.

TiO2−x/Ag/rGO composites as effective photocatalysts for the degradation of organic pollutants

The incorporation of Ti3+ and oxygen vacancies in the TiO2−x NRs/Ag/rGO composites reduces the bandgap of TiO2 and extends the visible light absorption range due to the SPR effect of Ag NPs and the reduced light reflection in the presence of rGO.

Rational design of praseodymium ferrite decorated on reduced graphene oxide for the electrochemical detection of quercetin

According to this research, Quercetin (QR) is a crucial part of the human diet, making inexpensive, quick, and portable sensors necessary for its determination in food samples, dietary supplements, and pharmaceuticals. So, we prepared a hydrothermally synthesized PFO/RGO electrochemical sensor for quercetin detection. In this case, the synthesized composite was verified by XRD, FESEM, HRTEM, EDX, Raman, and XPS which confirms the crystallinity, particle-shaped irregular arrangements, presence of RGO, and elemental composition. EIS and CV analysis revealed the electrode material's electrical conductivity was increased by the RGO nanosheets, which supported the electrical conductivity of PFO. The electrochemical measurements proved the designed PFO/RGO sensor's excellent QR sensitivity and selectivity. The proposed sensor was optimized for sensing QR followed by a linear response of 0.01–225 µM and LOD of 0.026 µM with an excellent sensitivity of 1.674 µA µM−1 cm−2. We also evaluated the practical performance of the proposed PFO/RGO sensor against QR in the actual fruit samples, which showed good recovery results.

Enhancement of integrated nano-sensor performance comprised of electrospun PANI/carbonaceous material fibers for phenolic detection in aqueous solutions

The detection of trace levels of organic residue in water samples is a key health issue. This manuscript describes the fabrication of integrated nano-sensors composed of electrospun microfibers consisting of a nanocomposite of carbonaceous materials (CNMs) containing polyaniline (PANI) and polycaprolactone (PCL) for phenolic detection in aqueous solutions. The morphology of the resulting microfiber composite was characterized by scanning electron microscopy. It revealed elongated fibers with a highly interconnected web-like pattern in the presence of reduced graphene oxide (rGO). Shorter microfibers were observed in the composite filled with multi-walled carbon nanotubes (MWCNTs), whereas large agglomerates were formed upon the incorporation of single-walled CNTs (SWCNTs) and graphene 300 (G300). Comparative analysis showed that the PANI/CNM sensors exhibited the best electrochemical properties, in particular in the presence of rGO and MWCNTs, where greater electrical conductivity was achieved, i.e., 4.33 × 10−3 and 7.22 × 10−4 S/cm, respectively, as compared to the PANI-PCL sensor (3.79 × 10−4 S/cm). All the PANI/CNM sensors exhibited high sensitivity. Notably, PANI/rGO was found to have a detection limit of 8.34 × 10−3 µM for aminophenol. All the sensors exhibited good selectivity in the presence of interference to detecting phenolic compounds in aqueous solutions, thus confirming their value for industrial applications.

The Impact of Graphene in Na2FeP2O7/C/Reduced Graphene Oxide Composite Cathode for Sodium-Ion Batteries

This study presents a thorough investigation of Na2FeP2O7 (NFP) cathode material for sodium-ion batteries and its composites with carbon and reduced graphene oxide (rGO). Our findings demonstrate that rGO sheets improve cycling performance in NFP/C/rGO composite in the absence of solid electrolyte interphase (SEI)-stabilizing additives. However, once SEI is stabilized with the help of fluoroethylene carbonate electrolyte additive, NFP with carbon additive (NFP/C) exhibits a superior electrochemical performance when compared to NFP/rGO and NFP/C/rGO composites. The decreases in capacity and rate capability are proportional to the amount of rGO added, and lead to an increase in overvoltage and internal resistance. Based on our results, we attribute this effect to worsened sodium kinetics in the bulk of the electrode—the larger ionic radius of Na+ hinders charge transfer in the presence of rGO, despite the likely improved electronic conductivity. These findings provide a compelling explanation for the observed trends in electrochemical performance and suggest that the use of rGO in Na-ion battery electrodes may present challenges associated with ionic transport along and through rGO sheets.

Enhanced photocatalytic degradation of Rhodamine B employing transition metal (Fe, Cu, Co) doped ZnO/rGO nanostructures synthesized by electrospinning-hydrothermal technique

In the present work, the use of transition metal-doped zinc Oxide/reduced graphene oxide (ZnO/rGO) nanostructures for photocatalytic applications was investigated. The paper presents a novel and cost-effective electrospinning-assisted hydrothermal method of synthesizing these nanostructures onto fluorine-doped tin oxide (FTO) substrates. The research focuses on the effects of the rGO sheets attached to the ZnO nanostructure and of Fe, Cu, and Co ions as dopant transition metals. The doped ZnO/rGO photocatalysts obtained were characterized using various techniques, including Field Emission Scanning Electron Microscopy (FE-SEM), Energy Dispersive X-ray (EDX), X-Ray Diffraction (XRD), Raman spectroscopy, and Photoluminescence (PL). The results showed that the doped ZnO/rGO samples exhibited pure composition, hexagonal wurtzite structure with high crystallinity, and nanorod-like morphologies with reduced mean diameters due to doping and the rGO anchoring. Additionally, the PL experiments demonstrated that charge carrier recombination was effectively inhibited for the doped ZnO/rGO samples. The photocatalytic performances of the undoped and doped ZnO/rGO nanostructures were tested through the degradation of Rhodamine B (RhB) dye under simulated sunlight irradiation. An improvement in photocatalytic activity compared to pristine ZnO was achieved mainly due to dopants and the presence of rGO, both of which intensified the separation of photogenerated electron-hole pairs and thus hindered their recombination. The study also acknowledges some scientific challenges in controlling the doping process to achieve consistent and uniform properties. However, despite these issues, the potential applications and advantages of transition metal-doped ZnO/rGO nanostructures make them promising materials for future efficient and sustainable photocatalytic applications.

Electrodeposition and corrosion behavior of Sn and Sn-reduced graphene oxide coatings on mild steel from the non-cyanide acid chloride bath solution

Reduced graphene oxide (rGO) derived from graphite has received attention among researchers because of its special unique characteristic properties. Based on the studies, rGO-based coatings on stainless steel (SS) act as an anti-corrosive protective coating on stainless steel. Herein, we prepared a few layered rGO via graphite oxide by a simple thermal exfoliation of graphite oxide. Tin and Sn-rGO coatings have been electrodeposited on SS using an optimized acid chloride bath composition in the absence and presence of rGO respectively. The prepared specimens were subjected to an aggressive corrosive environment (aqueous 5% NaCl). The corrosion behavior of Sn and Sn-rGO composite coating has been examined by potentiodynamic polarization and electrochemical impedance spectroscopic (EIS) techniques. The potential shifted towards the negative region after polarization for Sn-rGO composite coating compared to pure Sn coating. Also, Sn-rGO composite coating exhibits more resistance when subjected to EIS measurements in 5% NaCl. The change in the surface morphology of coatings before and after exposure to corrosive environments has been observed by Scanning electron microscopy. After exposure to aqueous 5% NaCl, Sn coated specimen exhibited pores on the SS surface whereas fewer pore structures were observed on the SS surface for Sn-rGO coating. The results reveal a significant increase in anti-corrosion properties of Sn-rGO on SS compared to that of pure Sn coating.

Multifunctional performance of core–shell rGO@Fe3O4 on the mechanical, electrical/thermal, EMI, and microstructure properties of cement-based composites

This research study focuses on the development of a multifunctional cement nanocomposite using reduced graphene oxide (rGO) nanosheets. To address the challenges of rGO dispersion, a core–shell structure of rGO@Fe3O4 (rGO@F) was investigated in cement paste. The rGO@F nanohybrid was thoroughly characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transforms infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). The main objectives of this study were to improve the mechanical properties, electrical conductivity, thermal conductivity, and chemical properties of the cement composite through the incorporation of rGO@F. The performance of the cement paste containing rGO0.1@Fe3O4 (0.1 wt% rGO and 1 wt% Fe3O4) was evaluated, and it was found that its toughness and compressive strength were significantly enhanced compared to the reference sample. Furthermore, the addition of rGO@F led to a remarkable increase in the electrical and thermal conductivity of the modified cement composite, attributed to the formation of conductive pathways facilitated by the rGO nanosheets. Comprehensive analyses including XRD, TGA, differential scanning calorimetry (DSC), thermally assisted microscopy (TAM), FTIR, and X-ray photoelectron spectroscopy (XPS) confirmed that the rGO@F nanohybrid had a significant impact on the chemical properties and hydration process of the hardened cement paste. SEM images revealed a more compact microstructure of the cement paste in the presence of rGO@F, demonstrating its role in crack inhibition. Additionally, an increase in the formation of improved hydration crystals such as tobermorite and jennite was observed. The core–shell structure of rGO@F exhibited exceptional electromagnetic wave absorption properties due to its layered configuration, effectively trapping the electromagnetic waves. Overall, this research study highlights the successful fabrication of a multifunctional cement nanocomposite through the incorporation of rGO@F. The findings demonstrate significant improvements in mechanical strength, electrical conductivity, thermal conductivity, chemical properties, crack inhibition, and electromagnetic wave absorption. This research contributes to the advancement of cement-based materials with enhanced performance and opens up avenues for various applications in fields such as construction, infrastructure, and telecommunications.

Graphene oxide worsens copper-mediated embryo-larval toxicity in the pacific oyster while reduced graphene oxide mitigates the effects

Due to their properties, graphene-based nanomaterials (GBMs) are triggering a great interest leading to an increase of their global production and use in new applications. As a consequence, their release into the environment is expected to increase in the next years. When considering the current knowledge in the evaluation of GBMs ecotoxic potential, studies aiming to evaluate the hazard associated to these nanomaterials towards marine species and particularly considering potential interactions with other environmental pollutants such as metals are scarce. Here we evaluated the embryotoxic potential of GBMs, which include graphene oxide (GO) and its reduced form (rGO), both individually and in combination with copper (Cu) as a referent toxicant, towards early life stages of the Pacific oyster through the use of a standardized method (NF ISO 17244). We found that following exposure to Cu, dose-dependent decrease in the proportion of normal larvae was recorded with an Effective Concentration leading to the occurrence of 50% of abnormal larvae (EC50) of 13.85 ± 1.21 μg/L. Interestingly, the presence of GO at a non-toxic dose of 0.1 mg/L decreased the Cu EC50 to 12.04 ± 0.85 μg/L while it increased to 15.91 ± 1.57 μg/L in presence of rGO. Based on the measurement of copper adsorption, the obtained results suggest that GO enhances Cu bioavailability, potentially modifying its toxic pathways, while rGO mitigates Cu toxicity by decreasing its bioavailability. This research underscores the need to characterize the risk associated to GBMs interactions with other aquatic contaminants and supports the adoption of a safer-by-design strategy using rGO in marine environments. This would contribute to minimize the potential adverse effects on aquatic species and to reduce the risk for economic activities associated to coastal environments.

A One –Pot Hydrothermal Synthesis of rGO-Mediated CuS/MnS Nanocomposites: Energy Storage and Dye Removal Applications

A one-pot hydrothermal method was used to prepare reduced graphene oxide mediated CuS/MnS (CMS/rGO) nanocomposites. The XRD result revealed that the hexagonal structure of CMS/rGO with the crystallite size is about 24 to 35 nm, respectively. The presence of rGO in the CMS structure was confirmed through Raman analysis. The chemical states of CMS3/rGO nanocomposites were confirmed by the XPS analysis. From this, the observed binding energy values are in good agreement with the presence of Cu, Mn, S, O and C, respectively. The rod-like morphology of the CMS3/rGO nanocomposites was obtained by using HR-TEM. The optical property of the product was analyzed through UV-DRS and PL. The observed absorption and emission peaks are red-shifted when CuS/MnS concentration increases. It is attributed due to the increases in crystallite size. The calculated band gap energy values are decreased with increasing crystallite size. The electrochemical properties of the products show a pseudocapacitor nature (832 Fg−1) with excellent capacitance retention of 97%. The degradation efficiency of CMS3/rGOcatalyst nanocomposite shows a good efficiency of 96% and 91% against CR and CV dyes.

Characterization of Synthesized NiCo2O4 with Trisodium Citrate for Supercapacitor Material: A Preliminary Study

Supercapacitors can be called electrostatic double-layer capacitors (EDLCs) or pseudo-capacitors based on their energy storage mechanism. Pseudo-capacitors with metal oxide electrodes that transmit electric charge offer great application power but low stability. This study aims to characterize trisodium citrate (TSC) modified NiCo2O4/rGO electrodes as a preliminary study for the NiCo2O4 nanoparticle pseudo-capacitor. The materials were characterized using SEM (Scanning Electron Microscopy), XRD (X-Ray Diffractometer), FT-Raman (Fourier Transform Raman Spectroscopy), and FTIR (Fourier Transform Infrared Spectroscopy). All of these analyses confirmed that NiCo2O4 was manufactured successfully using TSC. At XRD, the angles of 2????, namely 45.04 and 53.34°, matched the plane of the cubic phase nanorod crystals of NiCo2O4 with values of 400 and 511, respectively. In the Raman examination, the presence of rGO, which increased the crystallinity of NiCo2O4 nanoparticles, was confirmed. FTIR analysis indicated that the 1550-1600 cm−1 corresponds to a C=C functional group in an aromatic ring or a C=O ????-???? structure, and the wavenumber of 2300 cm−1 corresponds to the OH group in TSC, an alkanoate derivative. SEM analysis determined that NiCo2O4 nanoparticles with 1 mmol TSC are the ideal material for supercapacitor electrodes, as the structure is the most uniform, soft, and tidy. Further analysis is needed to confirm the stability of the modified material.