In this study, we present microporous carbon (MPC), hollow microporous carbon (HMC) and hierarchically porous carbon (HPC) to demonstrate the importance of strategical designing of nanoarchitectures ...in achieving advanced catalyst (or electrode) materials, especially in the context of oxygen reduction reaction (ORR). Based on the electrochemical impedance spectroscopy and ORR studies, we identify a marked structural effect depending on the porosity. Specifically, mesopores are found to have the most profound influence by significantly improving electrochemical wettability and accessibility. We also identify that macropore contributes to the rate capability of the porous carbons. The results of the rotating ring disk electrode (RRDE) method also demonstrate the advantages of strategically designed double-shelled nanoarchitecture of HPC to increase the overall electron transfer number (
n
) closer to four by offering a higher chance of the double two-electron pathways. Next, selective doping of highly active Fe-N
x
sites on HPC is obtained by increasing the nitrogen content in HPC. As a result, the optimized Fe and N co-doped HPC demonstrate high ORR catalytic activity comparable to the commercial 20 wt% Pt/C in alkaline electrolyte. Our findings, therefore, strongly advocate the importance of a strategic design of advanced catalyst (or electrode) materials, especially in light of both structural and doping effects, from the perspective of nanoarchitectonics.
This study elucidates the role of each class of nanopore by in-depth electrochemical analysis of three types of ZIF-8-derived carbons. Also, engineered co-doping of Fe and N is found essential to selectively form Fe-N
x
sites in the carbon matrix.
Functionalization is an important way to breed new properties and applications for a material. This review presents an overview of the progresses in functionalized hexagonal boron nitride (h-BN) ...nanomaterials. It begins with an introduction of h-BN structural features, physical and chemical properties, followed by an emphasis on the developments of BN functionalization strategies and its emerging properties/applications, and ends with the research perspectives. Different functionalization methods, including physical and chemical routes, are comprehensively described toward fabrication of various BN derivatives, hetero- and porous structures,
etc.
Novel properties of functionalized BN materials, such as high water solubility, excellent biocompatibility, tunable surface affinities, good processibility, adjustable band gaps,
etc.
, have guaranteed wide applications in biomedical, electronic, composite, environmental and "green" energy-related fields.
Chemical and physical functionalization of hexagonal boron nitride materials breeds new properties and applications.
Developing the next-generation high-energy density and safe batteries is of prime importance to meet the emerging demands in electronics, automobile industries and various energy storage systems. ...High-voltage lithium-ion batteries (LIBs) and solid-state batteries (SSBs) are two main directions attracting increasing interest in recent years, due to their potential applications in the near future. In both kinds of batteries, the electrolytes play a pivotal role but also create several bottleneck problems. In this review, recent progress in designing electrolytes for high-voltage LIBs and SSBs is summarized. First, the solvents, additives, ionic liquids and superconcentrated salts strategies for constructing high-voltage liquid electrolytes are reviewed, and then the applications of inorganic solids, solid polymers, gels and ionic liquids in solid-state electrolytes are presented. Finally, the general design rules of the electrolytes and their current limitations and future prospects are briefly discussed.
Borophene, a monolayer of boron, has risen as a new exciting two-dimensional (2D) material having extraordinary properties, including anisotropic metallic behavior and flexible ...(orientation-dependent) mechanical and optical properties. This review summarizes the current progress in the synthesis of borophene on various metal substrates, including Ag(110), Ag(100), Au(111), Ir(111), Al(111), and Cu(111), as well as heterostructuring of borophene. In addition, it discusses the mechanical, thermal, magnetic, electronic, optical, and superconducting properties of borophene and the effects of elemental doping, defects, and applied mechanical strains on these properties. Furthermore, the promising potential applications of borophene for gas sensing, energy storage and conversion, gas capture and storage applications, and possible tuning of the material performance in these applications through doping, formation of defects, and heterostructures are illustrated based on available theoretical studies. Finally, research and application challenges and the outlook of the whole borophene’s field are given.
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•Effect of three different treatments to lignocellulose content of sugarcane biomass.•Direct-carbonization of sugarcane biomass to obtain anode for Na-ion battery.•Optimized carbon ...anode shows extremely low voltage plateau and outstanding stability.•In situ TEM study reveals small volume changes in the carbon after charge-discharge.
Development of low-cost anode for sodium-ion battery (NIB) has become the most desirable target in today’s energy demanding society. In this work, we present different treatments of sugarcane biomass to alter the lignocellulose compositions to obtain low-cost porous carbon as NIB’s anode. The optimized sugarcane biomass derived carbon presents the initial reversible capacity of 229 mAh g−1 and the reversible capacity of 189 mAh g−1 at 100 mA g−1 after 50 cycles. It is worth noting that the carbon also exhibits an extremely low voltage plateau with 74.2 % of discharge capacity originating from the voltages below 0.5 V. In addition, the sugarcane biomass derived carbon displays an ultra-stable capacity with almost no attenuation even after 2000 cycles. In consideration of the low voltage plateau, we also calculated the relative energy density (ER, combination of the capacity and voltage plateau), and a high ER of 500 Wh kg−1 in the first cycle and 416 Wh kg−1 after 50 cycles are obtained. In situ TEM analysis was conducted to investigate the structural stability of sugarcane biomass derived carbon. Small volumetric changes are observed at different charge-discharge states, indicating the structural stability of our sugarcane biomass derived carbon during sodiation-desodiation process, which is conducive to the stable cycling of Na-ions.
Today many aspects of science and technology are progressing into the nanoscale realm where surfaces and interfaces are intrinsically important in determining properties and performances of materials ...and devices. One familiar phenomenon in which interfacial interactions play a major role is the wetting of solids. In this work we use a facile one-step plasma method to control the wettability of boron nitride (BN) nanostructure films via covalent chemical functionalization, while their surface morphology remains intact. By tailoring the concentration of grafted hydroxyl groups, superhydrophilic, hydrophilic, and hydrophobic patterns are created on the initially superhydrophobic BN nanosheet and nanotube films. Moreover, by introducing a gradient of the functional groups, directional liquid spreading toward increasing OH content is achieved on the films. The resulting insights are meant to illustrate great potentials of this method to tailor wettability of ceramic films, control liquid flow patterns for engineering applications such as microfluidics and biosensing, and improve the interfacial contact and adhesion in nanocomposite materials.
High‐quality ultrathin single‐crystalline SnSe2 flakes are synthesized under atmospheric‐pressure chemical vapor deposition for the first time. A high‐performance photodetector based on the ...individual SnSe2 flake demonstrates a high photoresponsivity of 1.1 × 103 A W−1, a high EQE of 2.61 × 105%, and superb detectivity of 1.01 × 1010 Jones, combined with fast rise and decay times of 14.5 and 8.1 ms, respectively.
It is essential for novel photodetectors to show good photoresponses, high stability, and have facile fabrication methods. Herein, an optimized electrospinning method to fabricate a photodetector ...based on nanowire arrays that has a wide spectral response range is demonstrated. Arrays of ZnO‐CdO hybrid nanowires are carefully fabricated fusing ZnO and CdO portions into the same nanowires and subsequently assembling those nanowires into a regular structure. Compared to pure ZnO or CdO nanowire arrays, the hybrid arrays show comparable photocurrent/dark current ratios and response speeds, but they possess a much wider spectral response range from ultraviolet to visible light. The optoelectronic and electronic properties of the ZnO‐CdO hybrid nanowire arrays are systematically explored. Based on this, a transparent and flexible photodetector made of ZnO‐CdO hybrid nanowire arrays is fabricated. It shows a high transparency of around 95% in the spectral range of 400–800 nm and maintains its properties even after 200 bending cycles. Importantly, the developed, simple method can be directly applied to many types of substrates and a transfer of the nanowires becomes unnecessary, which guarantees a high quality of the devices.
A photodetector based on ZnO‐CdO heterojunctions with a large photoresponse range and a fast response speed is fabricated. Its comprehensive photoelectric and carrier transport properties at different wavelengths, light intensities, and pressures are investigated. The detector is highly transparent at 400–800 nm and maintains its properties even after 200 bending cycles. This photodetector has a high potential for use in multicolor optoelectronic devices.
Smart implementation of novel advanced nanomaterials is the key for the solution of many complex problems of modern science. In recent years, there has been a great interest in the synthesis and ...application of boron nitride (BN) nanotubes because of their unique physical, chemical, and mechanical properties. By contrast, the synthesis, characterization and exploration of other morphological types of BN nanostructure - BN nanoparticles and BN nanosheets - have received less attention. However, the detailed investigations on advantages of every morphological BN type for specific applications have only recently been started. One of the promising directions is the utilization of BN-based nanohybrids. This review is dedicated to the in-depth analysis of recently published works on the fabrication and application of BN nanoparticles, nanosheets, and their nanohybrids. It covers a variety of developed synthetic methods toward fabrication of such nanostructures, and their specific application potentials in catalysis, drug delivery, tribology and structural materials. Finally, the review focuses on the theoretical aspects of this quickly emerging field.
Developing materials for “Nano-vehicles” with clinically approved drugs encapsulated is envisaged to enhance drug therapeutic effects and reduce the adverse effects. However, design and preparation ...of the biomaterials that are porous, nontoxic, soluble, and stable in physiological solutions and could be easily functionalized for effective drug deliveries are still challenging. Here, we report an original and simple thermal substitution method to fabricate perfectly water-soluble and porous boron nitride (BN) materials featuring unprecedentedly high hydroxylation degrees. These hydroxylated BNs are biocompatible and can effectively load anticancer drugs (e.g., doxorubicin, DOX) up to contents three times exceeding their own weight. The same or even fewer drugs that are loaded on such BN carriers exhibit much higher potency for reducing the viability of LNCaP cancer cells than free drugs.
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