Amphiphilic block copolymers (ABCs) are important in interface and particle stabilization. Following consideration of the various methods of synthesis of ABCs, mesophases and micelles of block copolymers and the solubilization and adhesion of ABCs are considered. The Figure shows micelles formed by a polystyrene‐poly(vinylpyridine) copolymer. Nanoparticles and ABC/nanoparticle hybrid systems are also reviewed.
The investigation of nickel phosphide (Ni5 P4 ) as a catalyst for the hydrogen (HER) and oxygen evolution reaction (OER) in strong acidic and alkaline environment is described. The catalyst can be grown in a 3D hierarchical structure directly on a nickel substrate, thus making it an ideal candidate for practical water splitting devices. The activity of the catalyst towards the HER, together with its high stability especially in acidic solution, makes it one of the best non-noble materials described to date. Furthermore, Ni5 P4 was investigated in the OER and showed activity superior to pristine nickel or platinum. The practical relevance of Ni5 P4 as a bifunctional catalyst for the overall water splitting reaction was demonstrated, with 10 mA cm(-2) achieved below 1.7 V.
Heteroatom-doped
porous carbon materials (HPCMs) have found extensive
applications in adsorption/separation, organic catalysis, sensing,
and energy conversion/storage. The judicious choice of carbon precursors
is crucial for the manufacture of HPCMs with specific usages and maximization
of their functions. In this regard, polymers as precursors have demonstrated
great promise because of their versatile molecular and nanoscale structures,
modulatable chemical composition, and rich processing techniques to
generate textures that, in combination with proper solid-state chemistry,
can be maintained throughout carbonization. This Review comprehensively
surveys the progress in polymer-derived functional HPCMs in terms
of how to produce and control their porosities, heteroatom doping
effects, and morphologies and their related use. First, we summarize
and discuss synthetic approaches, including hard and soft templating
methods as well as direct synthesis strategies employing polymers
to control the pores and/or heteroatoms in HPCMs. Second, we summarize
the heteroatom doping effects on the thermal stability, electronic
and optical properties, and surface chemistry of HPCMs. Specifically,
the heteroatom doping effect, which involves both single-type heteroatom
doping and codoping of two or more types of heteroatoms into the carbon
network, is discussed. Considering the significance of the morphologies
of HPCMs in their application spectrum, potential choices of suitable
polymeric precursors and strategies to precisely regulate the morphologies
of HPCMs are presented. Finally, we provide our perspective on how
to predefine the structures of HPCMs by using polymers to realize
their potential applications in the current fields of energy generation/conversion
and environmental remediation. We believe that these analyses and
deductions are valuable for a systematic understanding of polymer-derived
carbon materials and will serve as a source of inspiration for the
design of future HPCMs.
Polymeric carbon nitride (PCN), in either triazine or heptazine form, has been regarded as a promising metal-free, environmentally benign, and sustainable photocatalyst for solar hydrogen production. However, PCN in most cases only exhibits moderate activity owing to its inherent properties, such as rapid charge carrier recombination. Herein we present a triazine-heptazine copolymer synthesized by simple post-calcination of PCN in eutectic salts, that is, NaCl/KCl, to modulate the polymerization process and optimize the structure. The construction of an internal triazine-heptazine donor-acceptor (D-A) heterostructure was affirmed to significantly accelerate interface charge transfer (CT) and thus boost the photocatalytic activity (AQY=60 % at 420 nm). This study highlights the construction of intermolecular D-A copolymers in NaCl/KCl molten salts with higher melting points but in the absence of lithium to modulate the chemical structure and properties of PCN.
The present study concerns the one-step aqueous route production of carbonaceous materials loaded with carboxylic groups using hydrothermal carbonization of glucose in the presence of acrylic acid. This method provides a “green” solvent and surfactant free access to hydrophilic functionalized carbons with very good water dispersivity. The resulting materials were characterized using various methods including, FT-IR, Zeta Potential, N2 adsorption, Raman Spectroscopy, SEM, TGA, and 13C solid-state NMR. Among other possible applications of these types of materials, here, we discuss their use as adsorbents for heavy metals removal from aqueous solutions
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