are covalently bonded and their unique characteristics enable them to demonstrate special performance in applications and distinguish them from other conventional organic salts. [12][13][14] Recently, a significant attention has been paid to the use of zwitterions owing to their solubility in polar solvents for solution processing, [15][16][17] and dipole formation for the transfer of carriers [18][19][20] and ions. [21][22][23] Zwitterions have emerged as alternatives to the widely used building blocks such as conventional ionic groups, for developing new functional materials. The presence of both negative and positive ions in the same molecule enables zwitterions to develop interfacial dipole. The ability of zwitterions to develop interfacial dipole provides a new pathway to utilize them as interfacial layer in optoelectronic devices, including organic solar cells (OSCs), perovskite solar cells (PVSCs), and organic light-emitting devices (OLEDs), as well as electrolyte additives for energy devices such as lithium ion batteries (LIBs).It is well known that the ability to transport the charge carriers between the electrodes and organic layers is very crucial to obtain highly efficient electronic devices. [24] A mismatch between the energy levels of organic layers and inorganic electrodes leads to the generation of an energy barrier that hampers the extraction or injection of charge carriers. [25] To get rid of this obstacle, an interlayer between the electrodes and organic layers is applied to facilitate the transfer of charges in organic devices. In OLEDs, interlayers are used to enhance charge injection and reduce the height of Schottky barrier. While in the case of OSCs and PVSCs, apart from the enhancement in charge injection, they also play an important role to increase the built-in electric field across the active layer, ensuring efficient extraction of photogenerated charge carriers. [26][27][28][29][30] Therefore, the design and development of effective interlayer materials for interfacial modification are crucial for high-performance electronic devices. Recently, some significant advances have been demonstrated by applying an interfacial layer between the electrodes and organic layers, resulting in power conversion efficiencies (PCEs) to exceed 14% for single-junction OSCs by choosing appropriate photoactive layer. [31,32] Among different interlayer materials used so far, zwitterionic materials have been proved Zwitterions, a class of materials that contain covalently bonded cations and anions, have been extensively studied in the past decades owing to their special features, such as excellent solubility in polar solvents, for solution processing and dipole formation for the transfer of carriers and ions. Recently, zwitterions have been developed as electrode modifiers for organic solar cells (OSCs), perovskite solar cells (PVSCs), and organic light-emitting devices (OLEDs), as well as electrolyte additives for lithium ion batteries (LIBs).With the rapid advances of zwitterionic materials, high-performan...

Due to the capability of utilizing light energy to drive chemical reactions, photocatalysis has been widely accepted as a green technology to help us address the increasingly severe environment and energy issues facing human society. To date, a large amount of research has been devoted to enhancing the properties of photocatalysts. As reported, coupling semiconductors with metals is one of the most effective methods to achieve high-performance photocatalysts. The excellent properties of metal/semiconductor (M/S) nanocomposite photocatalysts originate in two aspects: (i) improved charge separation at the metal-semiconductor interface; and (ii) increased absorption of visible light due to the surface plasmon resonance of metals. So far, many M/S nanocomposite photocatalysts with different structures have been developed for the application in environmental remediation, selective organic transformation, hydrogen evolution, and disinfection. Herein, we will give a review on the M/S nanocomposite photocatalysts, regarding their fundamentals, structures (as well as their typical synthetic approaches), applications and properties. Finally, we will also present our perspective on the future development of M/S nanocomposite photocatalysts.

Nano-fibrillated cellulose (NFC), an abundant natural biomacromolecule, can have many applications, such as support/carrier for nanoparticles, due to its unique properties.

Self-ignition tests of a model scramjet combustor were conducted by using parallel sonic injection of gaseous hydrogen from the base of a blade-like strut into a supersonic airstream. The vitiated air was produced by burning H 2 , O 2 , and air to a stagnation temperature of 1000 -2100 K and a stagnation pressure of 0.8 -1.6 MPa. The effects of different parameters on the self-ignition limits were analyzed. In addition, the effects of the combustor's different wall con gurations on self-ignition limits were speci cally studied. It was found that the wall con gurations of the combustor had a signi cant effect on self-ignition limits, which might have variations of 420 -840 K deg in stagnation temperature; however, the local static temperature in the recirculation zones for different wall con gurations remained the same at approximately 1100 K. It was found that self-ignition could initiate at the exit of the combustor and this can be considered as a weak self-ignition characteristic.

No abstract