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In this study, in situ electrochemical Raman spectroscopy was applied to clarify the charge storage mechanism in three types of anodes, synthetic graphite, reduced graphene oxide (rGO), and nitrogen-doped reduced graphene oxide (N-rGO). The Li+ intercalation phenomenon was measured in LiPF6 electrolyte solution using a modified coin cell setup. The synthetic graphite anode showed the splitting of the G peak at the potential E < 0.2 V vs. Li/Li+, corresponding to the formation of a graphite intercalation compound (GIC) and its second-order 2D peak was found to be red-shifted due to charge transfer and induced strain in the potential region of 0.5 to 0.15 V vs. Li/Li+. In the case of rGO, the lattice defects assisted in large and early intercalation of electrolyte ions, which is confirmed by the red-shift in the G peak (∼36 cm−1) and its early disappearance below 0.3 V vs. Li/Li+, respectively. Unlike rGO, nitrogen vacancies in N-rGO provide active sites for Li+ intercalation, resulting in enhanced charge transfer, displayed by the large red-shift in the G peak (∼55 cm−1) and blue-shift in the D peak. In addition, a new Raman peak at 1850 cm−1 was observed in N-rGO for the first time, corresponding to the formation of a reversible intermediate species from the interaction between Li+ and nitrogen vacancies. This work demonstrates the use of a simple in situ technique to get insight into the nano-carbon electrodes during device operation and to reveal the role of doped nitrogen atoms for Li+ intercalation.

The current research deals with the study of boron and nitrogen co-doped reduced graphene oxide (BN-rGO) as a support material for iridium oxide (IrO2) nanoparticles for oxygen evolution reaction (OER) catalysis. The synthetic approach for the IrO2–BN-rGO catalyst involves the combination of pyrolysis and hydrothermal methods used for hierarchical nanostructures. BN-rGO possesses B–N, B–C, and N–C functional groups to support and stabilize the IrO2 catalyst nanoparticles. The altered electronic states of IrO2 on the BN-rGO support are compared with those of IrO2 on a non-doped support, rGO (IrO2–rGO), and on commercial BN sheets (IrO2–c-BN). The catalyst shows a low overpotential (300 mV at 10 mA cm−2), high current density (55 mA cm−2 at 1.65 V), and significantly high durability (12 350 cycles; 45 h) in an acidic environment. The high stability of IrO2–BN-rGO may result from the presence of a chemically and electrochemically stable B–N bond. We confirm that other functional groups (B–C and N–C) and the rGO framework are equally crucial for better attachment of IrO2 nanoparticles.

In recent times, non-conventional farming practices have emerged as a viable alternative to check soil degradation due to the indiscriminate application of agrochemicals. However, limited studies h...

Platinum nanoparticles (NPs) modified with alkylamines containing various aromatic rings (benzyl, naphtyl, anthryl, and pyrenyl) were synthesized as model cathode catalysts for fuel cells to investigate the role of aromatic surface modification agents on catalytic performance. Surface modification of Pt was confirmed by nuclear magnetic resonance spectra for NPs and thermogravimetric analysis for carbon-supported catalysts. Surface modification of Pt NPs with aromatic alkylamines improved the electrocatalytic activities for the oxygen reduction reaction, whose activity values increased by increasing the number of aromatic rings. The effect of surface modification on the electronic properties of the catalyst was evaluated by X-ray photoelectron spectroscopy. A large positive shift in the Pt 4f binding energy of surface-modified catalyst, especially for anthryl and pyrenyl modifications, was observed, indicating that one of the important factors is metal–support interaction facilitated by the aromatic groups through the π–π interactions with carbon support.

Modification of electrode surface using borylated-thiophene monomer resulted in the formation of a pre-formed solid electrolyte interface (SEI). The obtained ready-to use anodes did not show any loss in capacity during the first few cycles of charging and discharging. Herein, we report the synthesis and utilization of boron containing monomer to form an artificial SEI to reduce the interfacial resistance at SEI. Electropolymerization was performed via two methods, i) pre-modification and ii) in-situ modification. After the modification of the anodes, modified electrodes showed increased capacities, reduced capacity fading effect, and reduced interfacial resistance. Charge-discharge characteristics of half-cell with borylated thiophene polymer over graphite was studied and compared with graphite without any modification and polythiophene coated graphite.

Novel MoS2/acetylene black (AB) composite was developed using a single-step hydrothermal method. A systematic characterization revealed a few-layered, ultrathin MoS2 grown on the surface of AB. The inclusion of AB was found to increase the capacity of the composite and achieve discharging capacity of 1813 mAhg−1.