Two-dimensional graphene-like materials have numerous pores, large surface areas, and other excellent properties. And two-dimensional graphene-like materials have great potential in magnetic and spintronic devices. In this paper, we intercepted a fraction of g-C3N4 and prepared it into nanoribbons. We have calculated the g-C3N4 nanoribbons by studying the electronic structure of g-C3N4 nanoribbons to determine whether they can be used as spintronic and magnetic memory devices. Because the g-C3N4 nanoribbons have a narrow band gap and more overlapping wave functions, to turn the performance of the g-C3N4 nanoribbons, it was decided to dope transition metal Fe atoms. Subsequently, we found that the doped g-C3N4 nanoribbons with Fe atoms undergo a phase transition, from semiconducting property to half-metallic property, and the magnetic property of the g-C3N4 nanoribbons is enhanced by doped Fe atoms, so the performance of the g-C3N4 nanoribbons was improved.
We first constructed a new type of two-dimensional nanoribbon material by splicing C2N-h2D nanoribbon with BN nanoribbon, which is called C2N-h2D/BN nanoribbon. By studying the electronic structure of C2N-h2D/BN nanoribbons, we determine whether it can be used as a spintronic device. Secondly, to improve the performance of C2N-h2D/BN nanoribbons, we decided to doped the transition metal Mn、Fe、Co、Ni atoms. Finally, we find that the C2N-h2D/BN nanoribbons doped Fe atoms have half-metallicity, which is important for future applications in spintronics devices.
In recent years, inhibition of photoinduced electron and hole recombination is considered as a breakthrough to improve the photocatalytic degradation of pollutants. In this study, we successfully loaded ZnFe 2 O 4 (ZFO) microsphere onto BiFeO 3 (BFO) microcubes by a simple hydrothermal method. Under the effect of heterojunction between BFO and ZFO, the recombination rate of electron and hole was decreased significantly, leading to the enhanced photocatalytic effect. Morphology analysis shows that ZFO and BFO interface are closely combined. The photocatalytic experiments show that the degradation efficiency of tetracycline and methylene blue by BFO/ZFO-10% composites are 1.63 and 1.38 times higher than that of pure BFO. In addition, four cycles of experiments also proved that BFO/ZFO-10% has good stability and excellent magnetic properties, making the sample easy to be recovered. A possible electron hole transfer path on the base of a direct Z-scheme mechanism was proposed. This study provides a useful guide toward the design of the highly efficient and magnetic collectable photocatalysts by the introduction of magnetic component and the construction of heterojunction, and as-synthesized BFO/ZFO was proved to be a promising photocatalyst for the elimination of toxic organic molecules in groundwater.
The electronic structure of g-C3N4/C2N-h2D nanoribbons was investigated by first-principles calculations. As a splice structure, we first computed the three magnetic coupled states of g-C3N4/C2N-h2D nanoribbons. After self-consistent calculations, both the antiferromagnetic and paramagnetic coupling states become ferromagnetic coupling states. It was proved that the ferromagnetic coupling state is the most stable state. Thermodynamic stability was subsequently verified based on the ferromagnetic coupling state. It had a steady electron spin polarization, with a magnetic moment of 1 μB for each primitive cell. It changed from a direct band-gap semiconductor to an indirect band-gap semiconductor and exhibited the properties of a narrow band gap semiconductor through the analysis of the energy band and charge density. To transform the electronic structure, we adsorbed different transition metals in g-C3N4/C2N-h2D nanoribbons. We investigated the electronic structure of g-C3N4/C2N-h2D nanoribbons adsorbed by different transition metals. It was shown that the electronic structure of g-C3N4/C2N-h2D nanoribbons could be regulated by the adsorption of different transition metal atoms. Moreover, the adsorption of Fe and Ni can generate a 100% polarized current in the Fermi surface, which will provide more application potential for spintronics devices.
Reasonable design of high-performance catalysts with heterojunction to suppress the combination of electron-hole pairs has eyes gathered in photocatalytic field. Herein, a novel hydrangea-like ZnIn2S4/FePO4 with S-scheme heterojunction was constructed via an ultrasound-annealing process for photocatalytic H2 evolution. The composites showed remarkable photocatalytic H2 production performance (3.337 mmol h-1 g-1), which was approximately 7.5 times higher than that of blank ZnIn2S4 (0.446 mmol h-1 g-1). The improved photocatalytic H2 evolution was mainly ascribed to the accelerated electron-hole separation through the construction of S-scheme heterojunction in interface, and the hydrangea-like structure provided abundant active sites and huge specific surface area which was conducive to the exceptional photocatalytic activity. Simultaneously, both experimental and Density Functional Theoretical calculation results provided strong evidence for the transfer path of photogenerated carriers following the S-scheme heterojunction and the unique mechanism of photocatalytic H2 production was proposed. In addition, the hydrangea-like ZnIn2S4/FePO4 heterojunction photocatalyst showed a commendable stability with no distinct decrease after three cycle tests, demonstrating its potential as a recoverable photocatalyst. This work offered insights into the design and preparation of highly efficient photocatalysts with S-scheme heterojunction.
Abstract The electronic properties of h-BC 2 N/g-C 6 N 6 nanoribbons were calculated using the first principles method. Three states of ferromagnetic, antiferromagnetic, and paramagnetic coupling were set. The energy of the ferromagnetic coupling state was found to be the lowest, indicating that the final stable state was the ferromagnetic coupling state. The thermodynamic stability was also verified in the ferromagnetic coupling state. The h-BC 2 N/g-C 6 N 6 nanoribbons itself is magnetic with a magnetic moment of 2 μB and is a direct narrow band gap semiconductor material. In order to change the electronic properties, six different atoms (B, C, N, Al, Si, P) were adsorbed in the h-BC 2 N/g-C 6 N 6 nanoribbon, and their band structure and charge density were studied. The results show that the adsorption of different atoms in h-BC 2 N/g-C 6 N 6 nanoribbons will produce different results. Among them, the adsorption of N and P atoms changes its properties from a semiconductor to a half-metal, which can generate a 100% polarized current in the Fermi surface. This provides more development directions for spintronics devices.
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