Preparing dangling bonds by nanoholes on graphene oxide nanosheets and their enhanced magnetism

Here, metasurface magnetic carbon films synthesized via chemical vapour deposition (CVD) by using adamantane as a precursor and electron beam lithography (EBL) exhibited tuneable magnetic properties. The magnetic properties of carbon films were previously reported to occur from dangling bonds[1]. In this study, we observed a significant increase in saturation magnetization compared to the baseline film by controlling the array size of the metasurface film. Magnetic force microscopy (MFM) measurements confirmed the increasing saturation magnetization of the metasurface film. Magnetization originated from surface dangling bonds; smaller film sizes resulted in higher magnetization due to increased surface area. Furthermore, the saturation magnetization of the CVD carbon film could be tuned by controlling the humidity, and its prediction could be achieved through the utilization of the Raman technique. These findings highlight the potential of metasurface magnetic carbon films for developing tuneable magnetic microscale devices in areas, such as data storage, spintronics, and sensing.

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“…These ndings were also consistent with previous studies on cutting Te on tape and Para lm [25,43] and creating nanoholes in graphene oxide [44] .…”

Section: Resultssupporting

confidence: 92%

Enhanced and Tuneable Ferromagnetism in CVD-Synthesized Metasurface Carbon Films

Chaiyachad

Kaeokhamchan

Moontang

et al. 2023

Preprint

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“…The magnetization can be understood by analyzing the net spin density of the system (see Figure a), which is strongly localized around the functionalization site and distributed between the oxygen atom and few phosphorus atoms; however, the largest contribution is located around the P B atom, the one with the dangling bond. This result is consistent with the known fact that dangling bonds or diradicals can lead to induced local magnetization in non-magnetic materials. ,− Accordingly, the dangling electron from the P B atom is the responsible for the induced magnetism in the 1-OH system. This represents an alternative approach to induce a magnetic structure in a nonmagnetic system without doping with metallic atoms …”

Section: Results and Discussionsupporting

confidence: 90%

Functionalization-Induced Local Magnetization in Black Phosphorene

et al. 2023

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Functionalization of two-dimensional (2D) materials represents an efficient strategy to enhance their versatility, either for improving their stability under specific ambient conditions or for tuning their physical properties in a potentially relevant technological direction. In this study, we investigate with spin-polarized density-functional theory the electronic properties of phosphorene monolayers functionalized with hydroxyl and cysteine molecules. We show that functionalization leads not only to electronic states within the semiconducting gap but, more interestingly, to local magnetism as well. In consequence, ferro-or anti-ferromagnetic ground states can be obtained in dependence of molecular coverage, lattice direction (zigzag vs armchair) of the molecular adsorption, and, in the case of cysteine, molecular chirality. Based on an analysis of the obtained spin-dependent band structures, we propose to view functionalized phosphorene monolayers as bipolar magnetic semiconductors (BMS). In particular, the electronic parameters used to characterize BMS are shown to become increasingly distinct with increasing surface coverage. This suggests a possible route to design BMS via targeted molecular functionalization.

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“…Herein, we report the low-intensity pulse laser irradiation (LI) technique to synthesis a rich porous graphene oxide (GO) support to increase its surface dangling bonds. [18] This technique can precisely tune the in-plane porous structure of GO via tuning laser beam energy or LI time. [19] We applied the concept of the dangling bond of nanocarbons to extract metal species from their bulk metal counterparts at the ambient condition to convert them to SAC directly.…”

Section: Single-atom Catalysts (Sac) Can Boost the Intrinsic Catalytic Activity Of Hydrogen Evolution Reaction (Her) And Oxygen Reductionmentioning

confidence: 99%

Laser‐Irradiated Holey Graphene‐Supported Single‐Atom Catalyst towards Hydrogen Evolution and Oxygen Reduction

Khan

Liu

Arif

et al. 2021

Advanced Energy Materials

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Single‐atom catalysts (SAC) can boost the intrinsic catalytic activity of hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR). However, the challenge remains due to the complex synthesis process and insufficient stability. A sustainable approach is applied to synthesizing SACs through laser irradiation and gaining mesoporous graphene oxide (MGO). The surface dangling bonds of nitrogen‐doped MGO (NMGO) extract metal atoms species from Co or Fe metal foams and convert them to SAC via an appropriate synthesis approach. Notably, the Co‐NMGO electrocatalyst requires low potentials of 146 mV to convey a current density of 10 mA cm−2 towards HER. Similarly, the Fe‐NMGO electrocatalyst offers an onset of 0.79 V towards ORR in acidic solution. The individual metal atoms are confirmed via aberration‐corrected scanning transmission electron microscopy, and X‐ray absorption near‐edge structure and extended X‐ray absorption fine structure. Density functional theory calculations by applying the grand canonical potential kinetics model revealed that Co‐NMGO shows the optimum free reaction energy of −0.17 eV at −0.1 V for HER, and Fe‐NMGO has less limiting potential than that of Co‐NMGO for ORR case. This work opens a new approach towards the synthesis of SAC and its mechanistic understandings.

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Preparing dangling bonds by nanoholes on graphene oxide nanosheets and their enhanced magnetism

Abstract: The effects of dangling bonds on the magnetic properties of graphene oxide (GO) were studied experimentally by creating nanoholes on GO nanosheets.

Cited by 11 publications

References 53 publications

Enhanced and Tuneable Ferromagnetism in CVD-Synthesized Metasurface Carbon Films

Enhanced and Tuneable Ferromagnetism in CVD-Synthesized Metasurface Carbon Films

Functionalization-Induced Local Magnetization in Black Phosphorene

Laser‐Irradiated Holey Graphene‐Supported Single‐Atom Catalyst towards Hydrogen Evolution and Oxygen Reduction

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