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CFNCs with a high-curvature 3D hollow structure and rich interfaces enable activation of –CF and –CF2 groups, which results in cathode capacity of 1056 mAh g−1 and energy density up to 2487 Wh kg−1 beyond the theoretical limits of the Li-CFx system.

2D metal thiophosphate SnP2S6 was discovered as a new dielectric layer with a high dielectric constant (≈23), realizing a low subthreshold slope down to 69.4 mV dec−1 in the field effect transistor device geometry.

A novel complex [PtAg(dppm)2(CCC6H4COOCH3-4)2Cl] with two crystal morphologies as rod-like and prism was separately obtained by manipulating the recrystallization solvents. They exhibit glamorous morphology-dependent photoluminescence.

Hydrogen production from direct water electrolysis has long been pursued as a key that may revolutionize the hydrogen economy. With the rapid availability of electricity generated using renewable energy resources, this long-pursued target is now closer to reality than ever before. To date, most studies regarding electrocatalytic hydrogen evolution reaction (HER) are carried out in strong acidic/alkali electrolytes. However, hydrogen production from HER under extreme pH conditions has several drawbacks, including a corrosive working environment, the requirement of expensive anion/cation exchange membranes, and acidic/alkali withstanding electrocatalysts. The more sustainable approach to address these drawbacks is to deploy neutral/near-neutral electrolytes for HER. Regretfully, both theoretical discussions and practical applications regarding HER under neutral/near-neutral conditions are relatively rare and very elusive. In this review, we systematically discuss the current understandings of HER mechanisms under neutral conditions and analyze the influences of different types of neutral electrolytes. The most recent advances in the development of neutral HER electrocatalysts are summarized and exemplified, and general electrocatalyst design principles are highlighted. Lastly, we provide our perspective on the potential future research direction. We hope that this review inspires future endeavors to realize efficient HER for hydrogen production under neutral conditions.

Bifunctional catalysts for water-electrolysis are developed to simplify electrode- and cell-manufacturing. Hitherto, screening bifunction catalysts relies on experimental trials of high-performance cells and theoretical calculations of free-energy changes in the HER/OER intermediate steps, with high costs and constraints. Herein, we derive from the inevitable electrode-surface oxidation in water electrolysis and the semiconductor physics of such an oxidized electrode surface a band-diagram perspective: the oxidized electrode surface governing the catalytic activities in a bifunctional water-electrolysis cell should be a semiconductor with an effective bandgap not much larger than the HER-OER electrochemical potential gap of 1.23 eV. This perspective and its applications are elaborated with a set of experimental and DFT-computational results with FeP as a nominal bifunctional catalyst on nickel electrodes for the construction of a high-performance cell exhibiting 10 mA cm−2 at 1.40 V. The proposed “bandgap screening” is easy, low-cost, and applicable for expediting the development of new bifunctional catalysts.

The large size of sodium ions (Na+) restricts the choice of electrode materials; therefore, to realize low-cost energy storage systems, exceptional electrodes are required. Here, we have overcome this bottleneck by developing porous quasi-graphitic carbon (PGC) sheets at the surface of water-soluble KCl crystals as a green catalyst. The KCl crystals not only avoid the use of hazardous chemicals but also provide easy manipulation of the structural and surface chemistry of PGC sheets on a large-scale. The as-synthesized PGC sheets are enriched with micropores and amorphous reservoirs, which serve as mass transport channels and storage sites for Na+, respectively. Interestingly, when PGC sheets are employed as an anode in the sodium-ion battery, they showed an excellent reversible specific capacity of 237 mA h g−1 with outstanding cyclic stability by retaining 83.5% capacity after 250 cycles at 0.1 A g−1 at a capacity decay of 0.07% per cycle, while remaining stable up to 550 cycles when tested at 0.5 A g−1. Thus, the simple synthesis and large-scale production of PGC with high sodium storage capacity make it a potential candidate for secondary ion batteries.

A facile approach to fabricate nanoholes on the surface of a phosphor via a carbothermal reaction between C and BaMgAl10O17 was adopted. Drilling nanoholes greatly enhanced excitation light absorption and consequently increased the quantum efficiency, which provided new insight to help improve the luminescence efficiency of oxygen-containing phosphors.

Graphitic carbon (GC) coatings on the surface of functional materials have received tremendous attention because of their significant effect on surface chemistry. Herein, we have explained the interactions of a carbon source (acetylene) on the surface of functional material (tetrapod-zinc oxide, T-ZnO) through Density Functional Theory (DFT) calculations. DFT studies suggested that the growth of GC in the catalytic chemical vapour deposition (CCVD) process follows two typical pathways: one is chemo/physioadsorption of acetelyne on the T-ZnO surface, and the second one is decomposition of acetylene on the T-ZnO surface to activate carbon atoms that are restructured to generate a GC layer on the T-ZnO surface. Therefore, such a growth through catalytic accumulation reaction of carbon species on the substrate surface is named as vapour-dissociation-solid (VDS) growth. To support our theoretical observation, the GCs on the surface of T-ZnO are grown using acetylene through CCVD, and the results strongly support the VDS growth mechanism. The varying conditions of the CCVD process results in two types of microstructures including a smooth GC coating on T-ZnO that can also yield functional hollow GC nanostructures through acid leaching of the metallic part and ZnC8 nanoparticles embedded in GC walls. The high resolution microscopic analyses confirm the existence of ZnC8 in the nanospheres with an average size of 5.36 nm, which authenticates the decomposition followed by the solid deposition to form the GC on the substrate surface and supports a unique VDS growth mechanism. Therefore, an in-depth study of the GC growth mechanism and its fine coating on complex structures will facilitate research in the prevention of metal oxidation and the design of novel active materials for sensors, environment, energy and medical applications.

Helical nanofibers are prepared through in situ growth on the surface of a tetrapod-shaped ZnO whisker (T-ZnO), by employing a precursor decomposition method then adding substrate. After heat treatment at 900 °C under argon, this new composite material, named helical nanofiber-T-ZnO, undergoes a significant change in morphology and structure. The T-ZnO transforms from a solid tetrapod ZnO to a micro-scaled tetrapod hollow carbon film by reduction of the organic fiber at 900 °C. Besides, helical carbon nanofibers, generated from the carbonization of helical nanofibers, maintain the helical morphology. Interestingly, HCNFs with the T-hollow exhibit remarkable improvement in electromagnetic wave loss compared with the pure helical nanofibers. The enhanced loss ability may arise from the efficient dielectric friction, interface effect in the complex nanostructures and the micro-scaled tetrapod-hollow structure.

BaFe12O19 ferrite was firstly prepared through a sol–gel auto-combustion process, and then BaFe12O19/Fe3C/CNTs composites were synthesized from the acetylene chemical vapor deposition process with the introducing of BaFe12O19 ferrite at 400–600 °C. The structure and morphology of the BaFe12O19 ferrite and BaFe12O19/Fe3C/CNTs composites were studied using X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray. The microwave-absorbing properties of pure BaFe12O19 and such composites were investigated in the frequency range of 2–18 GHz through the evaluation of the experimental data based on the transmission line theory. The reflection loss results showed that the microwave absorption of BaFe12O19/Fe3C/CNTs composites performed better as the reaction temperature increasing up to 500 °C, due to the generation of the high-purity helical CNTs. The composites obtained at 600 °C performed well in electromagnetic wave loss at low frequency, owing to effective interfacial polarizations and good dispersion of magnetic nanoparticles. The composites were very potential for lightweight and strong electromagnetic attenuation materials at relatively low frequency.

CuO nanocrystals with as-designed morphologies such as uniform quasi-spherical nanoparticles and high-purity nanoleaves were synthesized by adjusting the addition of sodium hydroxide and hydrazine hydrate in aqueous solution at room temperature (25 °C). The increase of sodium hydroxide would accelerate the reaction rate and favor the nucleation of CuO nanocrystals. The decrease of the surface energy will promote the oriented attachment of nanocrystallites along the [−111] direction into nanowires and the final formation of two dimensional (2D) nanoleaves. Increasing the quantity of hydrazine hydrate could decrease the solution system energy and promote the aggregation of CuO nanocrystals from 2D nanoleaves into 3D quasi-spherical nanoparticles. All the CuO nanocrystals with different morphologies were characterized via transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM) and X-ray diffraction (XRD). The CuO nanoleaves exhibit excellent gas sensing performance in response to ethanol, showing the strongest response value of 8.22 at 1500 ppm ethanol for ∼260 °C.

A three-dimensional (3-D) multi-functional mixed valence CuII/CuI-MOF, {[Cu(CuI)2(2-pyzc)2H2O]2·H2O}n (Hpyzc = pyrazine-2-carboxylic acid), has been solvothermally synthesized and successfully characterized by FT-IR spectroscopy, elemental analysis, powder X-ray diffraction, thermal gravimetric analysis (TGA) and single-crystal X-ray diffraction. The structure posesses a 3-D open framework containing 1-D channels and shows a tcj topological network with the Schlafli symbol (43·612)(43)2. This MOF exhibits selective adsorption of CO2/H2 over CH4/N2 and excellent catalytic activity in the oxidation of benzylic compounds and three-component coupling reactions of aromatic alkynes, tosyl azide and diisopropylamine as a cooperative catalyst. The catalyst could be reused several times without significant degradation in catalytic activity.

Helical structures frequently exist in nature, and two commonly-seen examples are the curly hair of humans and the helical fujiko of luffa. Helical micro/nanoscale crystals have evolved to be an increasingly-intriguing form of crystals since their first cited observation more than half a century ago. In addition to carbon, a number of other materials have also been found to form helical structures spontaneously or in the presence of metallic catalysts. The special shape with extensive lattice strain, typically triggering a variety of unusual properties, makes such crystals of particular interest to the materials field. Up to this point, the growth kinetics of such helical nanocrystals still remains elusive. To resolve the growth kinetics, one must comprehend the length evolution in the growth of helical structures. In this report, we derive the analytical expression of the length of helical structures. We then evaluate the correlation between the kinetic length of helical crystals and a number of important parameters including the height, diameter and helical pitch, which are all observable via common optical and electronic microscopic techniques. Our investigation is applicable to explain not only the helical growth kinetics at the micro/nano-scale in the materials field, but also the helical growth phenomena in nature in general.