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Experimental evidence shows that CuFe2O4 exhibits excellent catalytic performance in the SCR reaction.

Cu@g-PAN/g-C3N4 exhibits excellent stability and excellent photocatalytic performance. The incorporation of g-C3N4 broadens the light absorption range.

Ultrathin PANI-doped g-PAN not only serves as the encapsulating agent to protect Cu from oxygen attack, but it also improves the efficiency of electron–hole separation, thereby enhancing the photocatalytic hydrogen evolution efficiency.

Lithium sulfur (Li–S) batteries have been investigated as ideal candidates for future high-density energy storage systems with the advantages of abundant reserves, high energy density and competitive cost. The key issues are the severe shuttling of polysulfides and sluggish redox kinetics. Herein, we report a novel metal–organic framework-derived Co2P–ZnS/ZnS–C nanocomposite constructed from inner Co2P–ZnS and outer ZnS–C heterostructures. Both the experimental results and theoretical calculations demonstrated that these dual electrocatalytic heterostructures enabled strong affinity with polysulfides and facilitated the reaction kinetics. Meanwhile, the hollow carbon polyhedron provided fast electron/ion transfer channels and effectively buffered volume expansion during cycling. As anticipated, a high initial capacity of 1503 mA h g−1 was achieved at 0.2C with Co–Zn/Zn–C/S as a cathode, together with excellent stability after 500 cycles at 1C. Even a high reversible capacity of 540 mA h g−1 was achieved at 1C after 200 cycles under an elevated sulfur loading of 3.65 mg cm−2. This work presents a new strategy for designing dual electrocatalytic hosts for immobilization and conversion of polysulfides, which may offer more opportunities as cathodes in stable Li–S batteries with high energy density.

Controlling magnetism in two dimensional (2D) materials is valuable to understand the current experimental observations and can guide the further design of functional devices. In this work, a 2D Mn3P monolayer with Mn-based Kagome frameworks is studied based on first principles calculations. The stability of the Mn3P monolayer is confirmed by ab initio molecular dynamics (AIMD) simulations and phonon dispersions. Possible magnetic configurations with distinguishing chirality are well defined, and the Mn3P monolayer is proved to show 2D noncollinear frustrated antiferromagnetism with positive spin chirality. Besides, the resulting magnetic anisotropic energy (MAE) can be controlled by in-plane-rotation of the spin orientation with a fixed 120° angle between each nearest pair of spins. To evaluate the spin transport properties, the in-plane anomalous Hall conductivity (AHC) is obtained by conducting Wannier interpolation. We find that the value of the AHC can be finely tuned by the explicit spin orientation and the sign of the AHC at the Fermi level can be inverted when the angle of spin orientation transfers from easy (30°) to hard (120°) rotation. Correspondingly, the k-space spin textures show the feature of on–off action owing to the rotation of the spin orientation. Our results provide a strategy for exploiting intrinsic spin orientation to achieve controllable spintronic devices with current synthesis techniques.

Adding particles of metal-organic frameworks (MOFs) into liquid electrolytes leads to semiliquid electrolytes, where nanoporous MOFs enclose anions while facilitating lithium-ion conduction. The improved transport efficiency of lithium-ions in semiliquid electrolytes boosts effective reaction kinetics, mitigates polarization, and produces affinitive electrolyte-electrode interfaces, which afford enhanced cycle durability for high-rate lithium batteries.

Molybdenum disulfide (MoS2) is one of the two-dimensional layered semiconductor transition metal dichalcogenides (TMDCs) with great potential in electronics, optoelectronics, and spintronic devices. Sulfur vacancies in MoS2 are the most prevalent defects. However, the effect of sulfur vacancies on the electronic structure of MoS2 is still in dispute. Here we experimentally and theoretically investigated the effect of sulfur vacancies in MoS2. The vacancies were intentionally introduced by thermal annealing of MoS2 crystals in a vacuum environment. Angle-resolved photoemission spectroscopy (ARPES) was used directly to observe the electronic structure of the MoS2 single crystals. The experimental result distinctly revealed the appearance of an occupied defect state just above the valence band maximum (VBM) and an upward shift of the VBM after creating sulfur vacancies. In addition, density functional theory (DFT) calculations also confirmed the existence of the occupied defect state close to the VBM as well as two deep unoccupied states induced by the sulfur vacancies. Our results provide evidence to contradict that sulfur vacancies indicate the origin of n-type behaviour in MoS2. This work provides a rational strategy for tuning the electronic structures of MoS2.

This work reports an enzyme-free glucose sensor based on nickel nanostructures electrodeposited on a fluorine-doped tin oxide (FTO) electrode modified with a silica nanochannel membrane (SNM). The SNM consists of a high density of nanochannels vertically oriented to the electrode surface, which can spatially confine the electrodeposition of nickel nanostructures and protect them to make Ni@SNM/FTO electrodes. In alkaline media, nickel could be converted to nickel oxyhydroxide that displayed catalytic activity toward the anodic oxidation of glucose. The electrodes could thus function as enzyme-free sensors for glucose detection. Under optimal conditions, the sensors exhibited an excellent analytical performance, with an analytical sensitivity as high as 62.3 μA mM-1 cm-2, a wide detection range from 10 μM to 12 mM and a low detection limit of 0.44 μM. Furthermore, given nickel nanostructures were embedded inside the nanochannels of the SNM (with a diameter of 2-3 nm), the sensor possessed anti-fouling ability and outstanding current stability, thus allowing the direct detection of glucose in dilute blood samples.

We present a high throughput study of the magnetic ground states for 90 transition metal dihalide monolayers TMX2 using density functional theory based on a collection of Hubbard U values. Stable geometrical phases between 2H and 1T are first determined. Spin-polarized calculations show that 50 out of 55 magnetic TMX2 monolayers are energetically prone to the 1T phase. Further, the magnetic ground states are determined by considering four local spin models with respect to different U values. Interestingly, 23 out of 55 TMX2 monolayers exhibit robust magnetic ground orderings which will not be changed by the U values. Among them, NiCl2 with a magnetic moment of 2 μB is a ferromagnetic (FM) insulator, while the VX2, MnX2 (X = Cl, Br and I), PtCl2 and CoI2 monolayers have noncollinear antiferromagnetic (120°-AFM) ground states with a tiny in-plane magnetic anisotropic energy, indicating flexible magnetic orientation rotation. The exchange parameters for both robust FM and 120°-AFM systems are analyzed in detail with the Heisenberg model. Our high-throughput calculations give a systematic study of the electronic and magnetic properties of TMX2 monolayers, and these two-dimensional materials with versatile magnetic behavior may have great potential for spintronic applications.

Organic double helical structures such as deoxyribonucleic acid (DNA) and poly(tetrafluoroethylene) play important roles in organisms and industry. Enlightened by recent experimental progress, a novel family of DNA-like inorganic metal free structures XYP (X = Si, Ge, Sn; Y = Cl, Br, I) were investigated using first principle calculations. All these structures were identified that as being semiconductors and, in particular, their band gaps corresponded to wavelengths of 419–561 nm, which implies semiconducting absorption in the visible spectra. Partial charge densities indicate an ideal space separation of electrons and holes, which can highly reduce the recombination of carriers in redox reactions. By comparing the band edge positions with the redox potentials of water, it was also found that XYPs are excellent photocatalysts for water splitting. Furthermore, the electron mobility of one-dimensional XYP is estimated to be up to 2164 cm2 V−1 s−1, which is comparable with or even larger than that of other nanomaterials. These systematic studies on DNA-like inorganic semiconductors with applications in photocatalytic water splitting and high speed electronic devices will open a new page in the world of inorganic-DNA nanomaterials.

Opening a sizable and tunable band gap in silicene without degrading the carrier mobility is quite desirable for high-speed switching devices. In the present work, the structural and electronic properties of two-dimensional silicene modulated by AsSb with van der Waals (vdW) interaction are investigated by density functional theory with vdW corrections. Notably, there is almost no lattice mismatch introduced in silicene/AsSb heterointerface, which is quite beneficial in comparison with silicene on other substrates. A sizable band gap (213–563 meV) appears in silicene owing to the breaking of the inversion symmetry due to the interface effects, which reveals a potential in applications in such as field effect transistors (FETs) at room temperature. In addition, the nearly linear band dispersion of silicene, guaranteeing the high carrier mobility, can be preserved in silicene/AsSb heterostructures considered in this work. Furthermore, the band gap can be effectively tuned by changing the interlayer distance between silicene and AsSb and, interestingly, an indirect–direct band gap transition occurs. Our results provide a possible direction for experimental fabrication and the applications of silicene-related materials.

The two-dimensional (2D) topological insulator (TI) is a promising material for designing dissipationless spintronic devices. Although many candidates have been found, few of them have a massive spin-orbit coupling (SOC) strength with high stability. In the present work, we demonstrate that h-Ga2Bi2 is a highly stable 2D TI with a massive Eg(Γ) at the Γ point of 1.477 eV, while the global band gap is 0.20 eV, which is sufficiently large for room temperature (∼26 meV). The edge states are greatly affected by the geometrical configuration of ribbon edges. The linear dispersive edge states still hold when the nanoribbon is limited to 1.7 nm, which actually realizes the ideal nanowire as theoretically derived in the field of TI. Most excitingly, an exotic 'O-atom bridge' is proposed here, and resides in the inner part of the nanoribbon, and so is thus highly protected from damage. The corresponding 'O-bridge states' display the interaction of electrons in a clear pattern, which leads to a better understanding of the 2D TI.

A new family of Si-based pentagonal monolayers is constructed on the basis of the okayamalite structure by means of first principles calculations. Phonon spectra and ab initio molecular dynamics simulations provide eloquent examinations for the dynamical and thermal stabilities of p-SiX (X = B, C, and N) monolayers. Electronic structures show that p-SiC and p-SiN are indirect semiconductors with band gaps of 2.35 and 4.98 eV by HSE hybrid functional, respectively. The carrier mobilities up to 2500 cm2 V−1 s−1 are quantitatively investigated by using deformation potential theory with effective mass approximation. And the band structures can be modulated monotonically under proper isotropic strains. This indicates that p-SiX can be used as field effect transistors or other electronic devices. More intriguingly, the band gap of p-SiC corresponds to the wavelength of 528 nm, showing a semiconducting character absorption in the green region of the visible spectra. Enlightened by prominent photocatalytic behavior of g-C3N4, we demonstrate that both band gap and band edges of p-SiC can meet the requirement of the reduction and oxidation levels in water splitting. The new type of Si-based nanomaterial offers an interesting alternative to diverse nanodevices and paves way for new metal-free photocatalysts.

The cytotoxicity of chemotherapeutic agents to healthy organs and drug resistance of tumor cells are believed to be the main obstacles to the successful cancer chemotherapy in the clinic. To ensure that anticancer drugs could be delivered to the tumor region, are quickly released from carriers in tumor cells and rapidly escape from endo/lysosomes, YPSMA-1-modified pH-sensitive polymeric micelles, which would be advantageous in recognizing the prostate specific membrane antigen (PSMA), were designed and fabricated for targeted delivery of paclitaxel to tumors based on the pH-sensitive diblock copolymer poly(2-ethyl-2-oxazoline)-poly(D,L-lactide) (PEOz-PLA) and YPSMA-1-PEOz-PLA for treating prostate cancer. HOOC-PEOz-PLA with a critical micelle concentration of 5.0 mg L(-1) was synthesized and characterized by (1)H NMR and gel permeation chromatography. The prepared YPSMA-1-modified micelles, about 30 nm in diameter, exhibited a rapid release behavior at endo/lysosome pH and a favorable ability of fast endo/lysosome escape as observed by confocal microscopy. More importantly, we evidenced for the first time that both endosome and lysosome escape existed for pH-sensitive micelles via real time tracing using confocal microscopy, and the real time endo/lysosome escape process was also presented. The YPSMA-1-modified micelles were very effective in enhancing the cytotoxicity of paclitaxel by increasing the cellular uptake in PSMA-positive 22Rv1 cells, which was verified the correlation with PSMA expression in tumor cells by flow cytometric analysis and confocal microscopy. Moreover, the active targeting and pH-sensitivity endowed YPSMA-1-modified micelles with a higher antitumor efficacy and negligible systemic toxicity in 22Rv1 xenograft-bearing nude mice compared with unmodified micelles and Taxol®. These results suggested that the application of combining YPSMA-1 modification with pH-sensitivity to polymeric micelles may be one approach in the efficient delivery of anticancer drugs for treating PSMA-positive prostate cancers.

A three-dimensional (3D) topological Dirac semimetal (TDSM) Cd3As2 has very recently been discovered, which can be turned into a variety of quantum phases by breaking either time reversal symmetry or inversion symmetry. Here, we present a density functional theory (DFT) study to systematically investigate the doping effects of 3d transition-metal (TM) atoms (Ti:Cu) in Cd3As2. The results reveal that the introduced 3d TMs lower the symmetries of the system, resulting in massive Dirac fermions with gap opening at the Dirac point. The substitution of Cr atoms could tailor Cd3As2 to a ferromagnetic half-metal due to the effective p–d exchange. The Monte Carlo simulations predict that the Curie temperature (Tc) of Cr–Cd3As2 is up to room temperature, suggesting powerful potential for further spintronic applications.

Recently, intensive efforts have been focused on the search of novel two-dimensional (2D) materials for memory and spintronic applications. In the present work, we provide a practical avenue for achieving the long-cherished nanomaterial via novel 2D periodic metalloporphyrin frameworks (referred to as M-Pp0 and M-Pp45, M = Cr, Mn, Fe, Co, Ni, Cu and Zn) with regularly and separately distributed transition-metals (TMs) by means of first-principles calculations combined with Monte Carlo simulations. The electronic and magnetic properties of these novel 2D systems are systematically investigated. Our results reveal that Ni-Pp0 and Zn-Pp0 are nonmagnetic, while Cr-Pp0, Fe-Pp0 and Cu-Pp0 are weak antiferromagnetic and Co-Pp0 is paramagnetic. For M-Pp45 frameworks, however, the spin couplings are all identified to be paramagnetic arising from their long spin coherence length. Remarkably, the introduced TMs have tremendous influence on the band gap of the M-Pp45 frameworks. What is more interesting is that the Mn-Pp0 framework exhibits long-range ferromagnetic spin coupling as well as half-metallic nature. By performing Monte Carlo simulations based on the Ising model, we further demonstrate that the Mn-Pp0 framework would possess a Curie temperature (TC) of 320 K, suggesting a real sense of room temperature is achieved. These results would shed light on future experimental researches on spintronics.

The electronic and magnetic properties of a series of one-dimensional carbon-free sandwich polymers [(Ge5)TM]∞ (TM = Ti, V, Cr, Mn, Fe) are examined, based on first principles calculations. Our results show that all of the five polymers are metallic and magnetic. The polymers [(Ge5)V]∞, [(Ge5)Cr]∞ and [(Ge5)Mn]∞ exhibit antiferromagnetic behavior, and the other two polymers [(Ge5)Ti]∞ and [(Ge5)Fe]∞ display ferromagnetic spin ordering. It is found that the magnetic moments are mainly contributed by the TM 3d orbitals. It is predicted that the magnetic properties of [(Ge5)TM]∞ polymers can be manipulated by the use of different combinations of TM atoms. This system is one of the few carbon-free sandwich polymers which can be used in spintronics. These results may pave the way for further experimental studies on molecular spintronics.