Boron-doped Reduced Graphene Oxide Research Articles

Boron-doped reduced graphene oxide as an efficient cathode in microbial fuel cells for biological toxicity detection

Electrodes with superior stability and sensitivity are highly desirable in advancing the toxicity detection efficiency of microbial fuel cells (MFCs). Herein, boron-doped reduced graphene oxide (B-rGO) was synthesized and utilized as an efficient cathode candidate in an MFCs system for sensitive sodium dodecylbenzene sulfonate (SDBS) detection. Boron doping introduces additional defects and improves the dispersibility and oxygen permeability, thereby enhancing the oxygen reduction reaction (ORR) efficiency. The B-rGO-based cathode has demonstrated significantly improved output voltage and power density, marking improvements of 75 % and 58 % over their undoped counterparts, respectively. Furthermore, it also exhibited remarkable linear sensitivity to SDBS concentrations across a broad range (0.2–15 mg/L). Notably, the cathode maintained excellent stability within the test range and showed significant reversibility for SDBS concentrations between 0.2–3 mg/L. The highly sensitive and stable B-rGO-based cathode is inspiring for developing more practical and cost-effective toxicant sensing devices.

Iron phthalocyanine integrated with boron-doped reduced graphene oxide for highly selective four-electron oxygen reduction: an experimental study

Iron phthalocyanine (FePc) has been integrated on boron-doped reduced graphene oxide (B-RGO) resulting in the composite, FePc@B-RGO which shows a highly selective four-electron oxygen reduction reaction.

Concurrent Thermal Reduction and Boron-Doped Graphene Oxide by Metal–Organic Chemical Vapor Deposition for Ultraviolet Sensing Application

We synthesized a boron-doped reduced graphene oxide (BrGO) material characterized by various electrical properties, through simultaneous thermal reduction and doping procedures, using a metal–organic chemical vapor deposition technique. X-ray photoelectron spectroscopy (XPS) was used to study the impact of the doping level on the B bonding in the reduced graphene oxide (rGO) layer that is influenced by the annealing temperature. The synthesized BrGO layer demonstrated a high B concentration with a considerable number of O-B bonds, that were altered by annealing temperatures. This resulted in a decreased work function and the formation of a Schottky contact between the BrGO and n-type Si substrate. Due to the higher proportion of B-C and B-C3 bonding in the BrGO/Si device than that in the rGO/Si, the decreased Schottky barrier height of the BrGO/n-Si vertical junction photodetector resulted in a higher responsivity. This study showcases a promise of a simple B-doping method in use to alter the electrical characteristics of graphene materials.

Increasing sensitivity and selectivity for electrochemical sensing of uric acid and theophylline in real blood serum through multinary nanocomposites

The sensing of theophylline (TP) and uric acid (UA) is important for the diagnosis and treatment of diseases in the early stages. While the first proofs show the potential of electrochemical sensors, the simultaneous detection of TP and UA is still not satisfactory. Herein we present an electrochemical sensor showing high sensitivity and selectivity for the detection of the two purine derivatives, TP and UA in blood serum. Key for this is a multinary nanocomposite which was specially designed for the sensing purpose and is based on titania nanoparticles, copper oxide, and boron-doped reduced graphene oxide, Au nanoparticles as also the modification of the supporting carbon electrode with 2-amino-5-mercapto-1,3,4-thiadiazole through electropolymerization. The study showed that the multinary nanocomposite improves the electrochemically active surface area and the electron transfer rate of the sensor, which together boosts the current response for the sensing strongly. It could be shown that the electrochemical sensor provides an excellent linear relationship between 0.5 nM and 10.0 µM for UA and for TP between 1.0 nM and 10.0 µM. Detection limits of 0.18 nM and 0.36 nM results for UA and TP, respectively. The sensitivity is 1.27 μA µM−1 cm−2 for UA and 1.06 μA µM−1 cm−2 for TP. Additionally, the method was used for the simultaneous measurements of UA and TP in real blood serum, which demonstrated the excellent applicability of the device.

“Quasi-In Situ Synthesis of Oxygen Vacancy-Enriched Strontium Iron Oxide Supported on Boron-Doped Reduced Graphene Oxide to Elevate the Photocatalytic Destruction of Tetracycline”

The efficient use of visible light is necessary to take advantage of photocatalytic processes in both indoor and outdoor circumstances. Precisely manipulating the in situ growth method of heterojunctions is an effective way to promote photogenerated charge separation. Herein, the SrFeO3@B-rGO catalyst was prepared by an in situ growth method. At a loading of 10 wt % B-rGO, the nanocomposites revealed an excellent morphology and thermal, optical, electrochemical, and mechanical properties. X-ray diffraction analysis revealed the cubic spinel structure and a space group of Pm̅3m for SrFeO3. High-resolution scanning electron microscopy and high-resolution transmission electron microscopy show the core-shell formation between SrFeO3 and B-rGO. Furthermore, density functional theory of SrFeO3 was performed to find its band structure and density of states. The SrFeO3@B-rGO nanocomposite shows the degradation rate of tetracycline (TC) reaching 92% in 75 min and the highest rate constant of 0.0211 min-1. To improve the catalytic removal rate of antibiotics, the efficiency of e- and h + separation must be improved, as well as the generation of additional radicals. Radical trapping tests and the electron paramagnetic resonance method indicated that the combination of Fe2+ and Fe3+ in SrFeO3 effectively separated e- and h+ while also promoting the development of the superoxide anion (•O2-) to accelerate TC degradation. The entire TC degradation pathway using high-performance liquid chromatography and its mechanism were discussed. As a whole, this study delineates that photocatalysis is a viable strategy for the treatment of environmental antibiotic wastewater.

Hydrogen storage in Nickel dispersed boron doped reduced graphene oxide

Graphene oxide (GO) based derivatives have been explored for hydrogen storage application, owing to their high surface area, low density and tunable pore size. However, under ambient conditions as desired for transport application, their storage capacity is poor. The use of nanohybrids of graphene oxide decorated with catalyst nanoparticles is emerging as a promising strategy to store atomic forms of hydrogen by invoking the spillover mechanism (in addition to storing molecular forms of hydrogen). Also, doping the substrate (GO) with light heteroatoms such as boron (B) have been envisaged for improving the enthalpy of adsorption of molecular hydrogen on the substrate. In the current work, GO based hybrids namely boron doped reduced graphene oxide (B-rGO) and Ni nanoparticle dispersed B-rGO (Ni-B-rGO) has been synthesized via freeze drying and hydrothermal route. The presence of various phases in the samples was identified using X-ray diffraction. Field-emission scanning electron microscopy was used to study the morphology; especially the 'wrinkling' in the GO based structures. The size and distribution of Ni nanoparticles was studied using transmission electron microscopy (size ∼1–2 nm and inter-particle distance of ∼20 nm). Raman spectroscopy was used to quantify the degree of disorder in the samples and additionally to demonstrate the existence of adsorbed molecular hydrogen. Fourier transform infrared spectroscopy studies showed the presence of various functional groups on carbon and further revealed the presence of atomic hydrogen generated by the spillover mechanism. X-ray photoelectron spectroscopy studies augmented the investigations to show the surface composition of Ni-B-rGO sample. The samples were further characterized for their hydrogen storage capacity using Sieverts apparatus (pressure-composition-isotherms) at three temperatures (77 K, 273 K and 298 K) and 20 bar H2 pressure. The B-rGO sample, showed promising storage capacity of ∼0.24 wt.% at 298 K, which increased to ∼0.58 wt.% at 273 K; which further increased to 8.2 wt.% at 77 K. The storage capacity of the Ni-B-rGO hybrid at the three temperatures (77 K, 273 K and 298 K) are: ∼6.9 wt.%, ∼0.41 wt.% and 0.16 wt.%, respectively.

Effect of graphene-based additives on mechanical strength and microstructure of gypsum plaster

In this study, graphene-based materials such as graphene oxide, reduced graphene oxide, and boron-doped reduced graphene oxide were synthesized, and their effects on the microstructure and mechanical properties of gypsum plaster were investigated. The graphene oxide (GO) sample was synthesized by modified Hummers’ method, and reduced graphene oxide (rGO) was obtained with the thermal reduction of GO. Boron doped reduced graphene oxide (B-rGO) was prepared via the impregnation method. The synthesized graphene-based materials were characterized using H 2 -TPR, TGA-DTA, XRD, FT-IR, SEM-EDS, TEM, Raman, and N 2 adsorption-desorption analysis. Analysis results confirmed that 450 o C was a sufficient temperature under an H 2 atmosphere to reduce GO and preserve rGO structure. XRD results revealed the presence of multilayer graphene structure in the rGO and B 2 O 3 crystals in the B-rGO sample. Multilayer graphene formation was also determined from the I 2D /I G ratio (0.1) of Raman analysis. Mechanical strength studies showed that while GO had a negative effect on both bending and compressive strength of gypsum plaster, rGO enhanced its bending and compressive strength. The addition of 0.1 wt% rGO added gypsum plaster increased the bending strength by 15.1% and compressive strength by 3.70%. SEM, He Pycnometry, and N 2 adsorption-desorption analyses revealed that rGO addition significantly changed the microstructure of gypsum plaster. The addition of B-rGO positively affected the compressive strength of the plaster and the highest increase was obtained as 8.6%; however, no significant change was observed in the microstructure of gypsum. • Electron microscopy images represented graphene nanosheets and graphene layers • X-ray diffraction results revealed the B 2 O 3 crystals in the boron-doped sample • Reduced graphene oxide increased the bending and compressive strength • Boron doped reduced graphene oxide enhanced the compressive strength • Reduced graphene oxide decreased the porosity of the gypsum

Boron doped RGO from discharged dry cells decorated Niobium pentoxide for enhanced visible light-induced hydrogen evolution and water decontamination

Upgradation in technology leads to the accumulation of a large amount of electronic waste and causes serious issues in the environment. Discharged dry cells are one such waste that needs proper monitoring. The present work deals with the synthesis of boron-doped reduced graphene oxide (BRGO) from graphite derived from dry cells. Nb2O5 (NbO) nanoflakes were decorated with BRGO. Structural and morphological characterizations confirm the formation of NbO-BRGO. NbO-BRGO showed enhanced photocatalysis compared to pristine BRGO and NbO. The photocatalytic H2 evolution was found to be 1742, 1216 and 855 µmol in the presence of NbO-BRGO, NbO and BRGO, respectively. The effect of sacrificial agents was studied and found TEOA to exhibit the highest activity. NbO-NBRO was further evaluated for the degradation of crystal violet (CV) dye under different light sources and was found to degrade 97.6 % under solar light. The reaction conditions like the effect of pH, catalyst dosage, and initial concentration were optimized carefully. The optical, electronic and photoelectrochemical characterizations of the materials indicate the decreased bandgap (2.70 eV), enhanced separation of photoexcited electrons and holes and superior current response in NbO-BRGO. The mechanism of photocatalysis has been predicted from LC-MS analysis insights. The NbO-BRGO exhibit good stability in the experiments performed under the light. The results indicate the suitability of the NbO-BRGO material for light-driven catalytic activity for energy production and environmental remediation.

Nitrogen and boron-doped reduced graphene oxide chemiresistive sensor for real-time monitoring dissolved oxygen in biological processes

We developed a nitrogen and boron-doped reduced graphene oxide (N, B-HRGO) based chemiresistive sensor to measure dissolved oxygen (DO) in a complex biological medium. The N, B-HRGO modified interdigitated micro electrode arrays (IDE) constructed as a chemiresistor by the drop-cast method. A silicon based fluorinated oxygen permeable membrane protects the surface from the interference and provides a specificity to the sensor. The sensor responded to the DO concentration changes due to modulated surface charge carrier concentration by the adsorbed dissolved oxygen molecule (Oad). For DO concentration range 0–5 mg.L−1 there was nearly 80% change in response for the sensor with membrane. The resistance of the N, B-HRGO film was measured at different DO concentrations in KNO3 solution and during the growth of Amycalotopsis methanolica bacterial fermentation. The study showed that the sensor is sensitive to the oxygen present in the solution and can detect DO consumption in a complex fermentation medium. The effect of water and the electrolyte salt ions present in the electrolyte was studied in detail. It was observed that the adsorption of water molecule increases the sensor resistance, whereas the salt ions have negligible effect on the sensor response. Because of the simple electrode structure, this chemiresistive sensor can measure DO in the micro bioreactors with a volume of few microliters. The N, B-HRGO chemiresistive sensor can also be used for DO measurement in other bioprocess applications.

Polymer hydrogel based quasi-solid-state sodium-ion supercapacitor with 2.5 V wide operating potential window and high energy density

The present work reports a quasi-solid state sodium ion-based asymmetric supercapacitor (ASC) device with nitrogen-doped reduced graphene oxide (NrGO) and boron-doped reduced graphene oxide (BrGO) electrodes. The choice of NrGO (BrGO) for the cathode (anode) is accomplished through a computational investigation of electrode quantum capacitances based on density functional theory (DFT). Nanocellulose is used as an electrode binder due to its biodegradability, enhanced wettability, good ion permeability, and low cost. The NaClO4-PVA based hydrogel membrane is the separator-less quasi-solid state gel electrolyte in the fabricated device. The specific capacitance of the NrGO || BrGO ASC device is obtained as 251.2 F g−1, at a current density of 1 A g−1 with a wide potential window of 2.5 V which is better than the previous reports. This device offers a better performance in comparison to the rGO||rGO, NrGO||NrGO and BrGO||BrGO symmetric supercapacitor (SSC) devices due to the synergistic effect of non-faradic capacitance and pseudocapacitance. The ASC device shows an energy density of 54.5 Wh kg−1 at a power density of 1.25 kW kg−1 and significant capacitance retention of 84.8% after 10,000 cycles at a high current density of 15 A g−1.

Promoting photocatalytic interaction of boron doped reduced graphene oxide supported BiFeO3 nanocomposite for visible-light-induced organic pollutant degradation

Tuning the morphology of the semiconductor heterojunction photocatalyst has attracted extensive attention for effective photocatalytic performance in the process of wastewater treatment. The combination of boron doped reduced graphene oxide (B-rGO) supported by Bismuth ferrite (BiFeO3) nanocomposite was fabricated via simple one-pot mild hydrothermal synthesis. Notably, the non-metal doping with reduced graphene oxide leads to an extra advantage in improving photophysical properties such as electrochemical impendence spectroscopy (EIS) and photocurrent measurements, which significantly increases the charge carrier recombination factor due to the density state value near to the Fermi energy level in the system. The intimate layer contact between the B-rGO and BiFeO3 nanocomposite is well established by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), UV–vis diffuse reflectance spectroscopy (UV-DRS), and Vibrating sample magnetometer (VSM). Furthermore, scanning electron microscopy (SEM) and Transmission electron microscopy (TEM) provide clear evidence for decorating hierarchically layered nanocomposite. The superior performance of the developed nanocomposite degradation efficiency was revealed towards Tetracycline (TC), and Rhodamine B (RhB) was chosen as an ideal model pollutant. The degradation efficiency was achieved for TC (86.7%) and RhB (99.4%). Also, the developed photocatalyst exhibited excellent photostability after four consecutive stability cycles. Finally, the non-metal doping technology was found to demonstrate excellent potential features in the field of environmental wastewater and pharmaceutical water detoxication.

Synthesis and characterisation of heteroatom-doped reduced graphene oxide/bismuth oxide nanocomposites and their application as photoanodes in DSSCs.

Semiconductor materials have been recently employed in photovoltaic devices, particularly dye-sensitized solar cells (DSSCs), to solve numerous global issues, especially the current energy crisis emanating from the depletion and hazardous nature of conventional energy sources, such as fossil fuels and nuclear energy. However, progress for the past years has been mainly limited by poor electron injection and charge carrier recombination experienced by DSSCs at the photoanode. Thus, novel semiconductor materials such as bismuth oxide (Bi2O3) have been investigated as an alternative photoanode material. In this study, Bi2O3 was integrated with nitrogen- or boron-doped reduced graphene oxide (N-rGO or B-rGO, respectively) via a hydrothermal approach at a temperature of 200 °C. Various instrumental techniques were used to investigate the morphology, phase structure, thermal stability, and surface area of the resulting nanocomposites. The incorporation of N-rGO or B-rGO into Bi2O3 influenced the morphology and structure of the nanocomposite, thereby affecting the conductivity and electrochemical properties of the nanocomposite. B-rGO/Bi2O3 exhibited a relatively large surface area (65.5 m2 g−1), lower charge transfer resistance (108.4 Ω), higher charge carrier mobility (0.368 cm2 V−1 s−1), and higher electrical conductivity (6.31 S cm−1) than N-rGO/Bi2O3. This led to the fabrication of B-rGO/Bi2O3 photoanode-based DSSCs with superior photovoltaic performance, as revealed by their relatively high power conversion efficiency (PCE) of 2.97%, which outperformed the devices based on N-rGO/Bi2O3, rGO/Bi2O3, and Bi2O3 photoanodes. Therefore, these results demonstrate the promising potential of heteroatom-doped rGO/Bi2O3-based nanocomposites as photoanode materials of choice for future DSSCs.

Enhancement of the electrocatalytic activity for the oxygen reduction reaction of boron-doped reduced graphene oxide via ultrasonic treatment

Commercial polymer electrolyte membrane fuel cells have relied on scares Platinum to catalyse the kinetically sluggish oxygen reduction reaction occurring at their anodes. Over the last decade organic materials, frequently based on graphitic structures have been demonstrated as promising alternative electrocatalysts to the noble metals. Researchers typically utilize ultrasonic treatment as part of the synthesis procedure to achieve homogeneous dispersion of graphitic carbon prior to. Herein we investigate the implications of the structural and compositional changes induced by the ultrasonication treatment on boron-doped reduced graphene oxide for oxygen reduction reaction. It is shown that ultrasonication pre-treatment prior to the boron doping and reduction of graphene oxide via hydrothermal process step leads to the increase of both substitutional B and electrocatalytic surface area, with associated reduction of average pore size diameter, leading to a significant improvement in the oxygen reduction reaction performance, with respect to the non-ultrasonicated material. It is proposed that the higher degree of substitutional doping of boron is a result of formation of the additional epoxy functionalities on graphitic planes, which act as a doping site for boric acid.

Heteroatom-Doped Reduced Graphene Oxide Nanosheets for Asymmetric Photo Supercapacitors

Graphene based materials have received great attention in energy storage applications such as supercapacitor because of their excellent in surface area, conductivity, and stability. However, their capacitance is limited by surface area in which the energy was stored via reversible ion adsorption at the electrode surface by electrochemical double layer capacitance (EDLC) mechanism. According to the previous studies, heteroatom doping results in a chemical activity changing and enhance electrochemical capacitance. In this work, we demonstrated the effect of boron-doped reduced graphene oxide on electrochemical performance. The electrochemical evaluation was performed in half-cell configuration in 1 M KOH using boron-doped reduced graphene oxide coated on FTO glass as working electrode. The boron-doped reduced graphene oxide shown the specific capacitance up to 370 F g−1 in 1 M KOH at 0.6 A cm-2. In addition, due to their photo active property, boron-doped reduced graphene oxide as an anode was coupled with NixCo3-xO4 as a cathode to investigate the performance of the asymmetric supercapacitor in dark and light conditions. This will be further explored for the development of the photo asymmetric supercapacitor application as a new sustainable energy storage device.

Chlorine-free electrochemical disinfection using graphene sponge electrodes

Graphene sponge electrodes were employed for chlorine-free inactivation of Escherichia coli from low conductivity water. The nitrogen-doped reduced graphene oxide (NRGO) sponge anode bearing more positive charge achieved complete E. coli inactivation (i.e., 5 log removal) in the anode–cathode configuration at 115 A m−2, versus 2.6 log removal using boron-doped reduced graphene oxide sponge anode. The bacteria were mainly inactivated via electrosorption and electroporation, as confirmed by the scanning electron microscopy. Storage of the electrochemically treated samples revealed further killing of the bacteria due to the damaged cell membranes. When using real tap water, 5.5 log E. coli removal required 5.70 kWh m−3, which was drastically lowered to 1.38 kWh m−3 using intermittent current and thus exploiting the capacitive properties of graphene. The developed graphene sponge anode does not form any chlorine, chlorate, or perchlorate, and holds great promise for efficient electro-disinfection without forming toxic disinfection byproducts.

Facile synthesis of nitrogen-doped and boron-doped reduced graphene oxide using radio-frequency plasma for supercapacitors

Heteroatom doping is an effective method to improve the capacitive performance of graphene-based materials. In this work, a facile and efficient radio-frequency (RF) plasma treatment strategy has been employed to achieve simultaneous doping and reduction of graphene oxide (GO). As a result, boron-doped and nitrogen-doped reduced graphene oxide (denoted as B-rGO and N-rGO) have been synthesized rapidly under relatively low temperatures compared with conventional thermal methods. The B-rGO and N-rGO present significantly improved specific capacitances as high as 345 F g−1 and 365 F g−1 at 0.2 A g−1, respectively, exhibiting a fourfold increase compared to that of GO before plasma treatment. Interestingly, the N-rGO shows better rate capability than the B-rGO. Furthermore, the mechanism of simultaneous doping and reduction by RF plasma treatment is discussed based on the diagnosis of emission spectroscopy. The high energy electrons and plasma-excited ions and radicals render effective reduction, etching, and doping of GO at the same time. Compared with high-temperature carbonization and wet chemical methods, our plasma treatment method is more energy-saving and eco-friendly. We believe this rapid and straightforward plasma treatment method reported here can be extended to the incorporation of various heteroatoms into graphene lattice for broad applications.

Removal of oxytetracycline by graphene oxide and Boron-doped reduced graphene oxide: A combined density function Theory, molecular dynamics simulation and experimental study

Graphene-based nanomaterials have demonstrated great potential in the field of environmental applications, especially on water treatment processes. Accordingly, herein, in order to be used as adsorbent in the removal of oxytetracycline (OTC), graphene oxide (GO) and boron doped reduced graphene oxide (B-rGO) was investigated. GO was obtained through the oxidation/exfoliation process using the modified Hummers’ Method and further etched by a thermal annealing approach to obtain B-rGO, utilizing boric acid as boron source for the study. FT-IR, TEM and XRD were used to characterize the morphology properties of GO and B-rGO and confirm the success of these synthesis. To evaluate the degradation potential of OTC by GO and B-rGO, pH of the sample, GO and B-rGO concentration, initial OTC concentration, reaction time and temperature has been selected as effective parameters. Based on the obtained experimental results GO and B-rGO were found to possess favorable adsorption efficiencies reaching 86% and 100% for GO and B-rGO, respectively, rapidly uptake rate with up to 85% of total removal occurring within the initial 10 min. In addition, it is noteworthy that OTC removal from solution was strongly dependent on pH but independent of temperature. The classical isotherm and kinetic adsorption models suggested that the process perfectly conformed to Freundlich and Pseudo-second-order model (R2 ≥ 0.95). Furthermore, density functional theory (DFT) simulation performed at the B3PW91 level of theory as well as a topological analysis were introduced to elucidate theoretically the interfacial interaction at the molecular-scale associated with OTC sorption on both adsorbents.

Enhancement of heterogeneous photo-Fenton performance of core-shell structured boron-doped reduced graphene oxide wrapped magnetical Fe3O4 nanoparticles: Fe(II)/Fe(III) redox and mechanism

In this paper, a kind of novel core-shell structured heterogeneous photo-Fenton catalyst, boron-doped reduced graphene oxide wrapped Fe3O4 (Fe3O4@B-rGO) composite, was successfully synthesized by heating the mixture of Borane-Tetrahydrofuran adduct and graphene oxide wrapped Fe3O4 (Fe3O4@GO) under reflux conditions. The core-shell structure of the catalyst had been confirmed by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photo electron spectra (XPS), and electron energy loss spectrum (EELS). The experimental results for Bisphenol A (BPA) degradation demonstrated that the as-prepared catalyst exhibited much higher photo-Fenton catalytic activity than Fe3O4 and reduced graphene oxide wrapped Fe3O4 (Fe3O4@rGO). Additionally, Fe3O4@B-rGO with mass concentration of doped boron at 9.3% exhibited the optimum catalytic property, in which system the BPA degradation kinetic rate constant was almost 1.96 times and 1.82 times of that in the systems with Fe3O4 and Fe3O4@rGO, respectively. Finally, the mechanism analyses verified that OH, O2− and h+ were the main reaction species in this system, and photo-electron generated by boron doped reduce graphene oxide (B-rGO) can accelerate the redox between Fe(II) and Fe(III). The excellent photo-Fenton performance, stability and magnetic separation properties make it promising for the degradation of organic compounds in waste water under visible light.

Boron-Doped Reduced Graphene Oxide with Tunable Bandgap and Enhanced Surface Plasmon Resonance.

Graphene and its hybrids are being employed as potential materials in light-sensing devices due to their high optical and electronic properties. However, the absence of a bandgap in graphene limits the realization of devices with high performance. In this work, a boron-doped reduced graphene oxide (B-rGO) is proposed to overcome the above problems. Boron doping enhances the conductivity of graphene oxide and creates several defect sites during the reduction process, which can play a vital role in achieving high-sensing performance of light-sensing devices. Initially, the B-rGO is synthesized using a modified microwave-assisted hydrothermal method and later analyzed using standard FESEM, FTIR, XPS, Raman, and XRD techniques. The content of boron in doped rGO was found to be 6.51 at.%. The B-rGO showed a tunable optical bandgap from 2.91 to 3.05 eV in the visible spectrum with an electrical conductivity of 0.816 S/cm. The optical constants obtained from UV-Vis absorption spectra suggested an enhanced surface plasmon resonance (SPR) response for B-rGO in the theoretical study, which was further verified by experimental investigations. The B-rGO with tunable bandgap and enhanced SPR could open up the solution for future high-performance optoelectronic and sensing applications.

Significant enhancement of the electrochemical hydrogen uptake of reduced graphene oxide via boron-doping and decoration with Pd nanoparticles

Development of advanced hydrogen storage materials with high capacity and stability is vital to achieve an envisaged hydrogen economy. Here, we report a uniformly dispersed Pd nanoparticles on the boron-doped reduced graphene oxide (Pd/B-rGO) as a novel nanocomposite for efficient hydrogen storage. The effects of the incorporation of Pd NPs and the substitution of boron atoms into the graphene-based nanomaterial matrix on the electrochemical hydrogen up-taking and releasing were comparatively studied using electrochemical techniques, and duly supported by density functional theory (DFT) calculations. The discharge capacities of the Pd-rGO and Pd/B-rGO nanocomposites were determined to be over 45 and 128 times higher than that of the Pd NPs, respectively, showing that the B doping and the rGO support played significant roles in the enhancement of the hydrogen storage capability. Moreover, the galvanostatic charging and discharging cycling tests demonstrated a high stability and efficient kinetics of the Pd/B-rGO nanocomposite in the H2SO4 electrolyte for hydrogen up-taking and release.