Metal halide perovskite nanocrystals have attracted great attention of researchers due to their unique optoelectronic properties such as high photoluminescence quantum yield (PLQY), narrow full width ...at half-maximum (FWHM), long exciton diffusion length and high carrier mobility, which have been widely used in diverse fields including solar cells, photodetectors, light-emitting diodes, and lasers. Very recently, metal halide perovskites have emerged as a new class of materials in photocatalysis due to their promising photocatalytic performance. In this review, we summarize the recent advances on synthesis, modification and functionalization, with a specific focus on the photocatalytic application of metal halide perovskite nanocrystals. Finally, a brief outlook is proposed to point out the challenges in this emerging area. The goal of this view is to introduce the photocatalytic application of the metal halide perovskites and motivate researchers from different fields to explore more potentials in catalysis.
Owing to their theoretical energy density of 2600 Wh kg−1, lithium–sulfur batteries represent a promising future energy storage device to power electric vehicles. However, the practical applications ...of lithium–sulfur batteries suffer from poor cycle life and low Coulombic efficiency, which is attributed, in part, to the polysulfide shuttle and Li dendrite formation. Suppressing Li dendrite growth, blocking the unfavorable reaction between soluble polysulfides and Li, and improving the safety of Li–S batteries have become very important for the development of high‐performance lithium sulfur batteries. A comprehensive review of various strategies is presented for enhancing the stability of the anode of lithium sulfur batteries, including inserting an interlayer, modifying the separator and electrolytes, employing artificial protection layers, and alternative anodes to replace the Li metal anode.
Anodes play an important role in resolving the issues of conventional lithium sulfur batteries. The most recent progress in anodes for lithium–sulfur batteries is introduced. To suppress the corrosion reaction that occurs and the formation of Li dendrites on the surface of lithium metal, various strategies are summarized. Employing alternative anodes for sulfur‐based rechargeable batteries is also discussed.
An integrated, selective interlayer structure is developed to further mitigate the diffusion of polysulfides, simply by coating the surface of a C–S cathode with a graphene/TiO2 film. It is found ...that the application of the graphene/TiO2 film as an interlayer enables the porous carbon nanotubes–S cathode to exhibit a high reversible specific capacity and extraordinarily excellent cycling stability.
Reduced graphene oxide/carbon nanotube/α-Ni(OH)2 (RGO/CNT/α-Ni(OH)2) composites are successfully synthesized by a one-pot hydrothermal route. The structural characterization of the composites by EDX, ...XRD, FT-IR, XPS, Raman, FESEM and TEM indicate that α-Ni(OH)2 nanoparticles with the size around 5 nm are randomly decorated onto three-dimensional (3D) hierarchical structure RGO/CNT. The electrochemical performances of the composites are evaluated by cyclic voltammogram, galvanostatic charge–discharge and electrochemical impedance spectroscopy. Interestingly, it is found that the electrochemical capacitance of the composites depends on the amount of CNTs to a large extent and RGO/CNT/α-Ni(OH)2 composite (GC2Ni2) with optimized ratio exhibits the high specific capacitance of 1320 F g−1 at 6 A g−1. In addition, the cycling measurements show that GC2Ni2 maintains a specific capacitance of 1008 F g−1 at 15 A g−1 after 1000 cycles corresponding to a reduction of capacitance of about 7.8%. The enhancement in specific capacitance and cycling stability is believed to be due to the 3D RGO/CNT conductive network which promotes not only efficient charge transport and facilitates the electrolyte diffusion, but also prevents effectively the volume expansion/contraction and aggregation of electroactive materials during charge–discharge process.
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•RGO/CNT/α-Ni(OH)2 composites were synthesized through one-pot hydrothermal route.•3D RGO/CNT structure improve the capacitive performance of α-Ni(OH)2 effectively.•GC2Ni2 can exhibit high specific capacitance, good cycling stability and coulombic efficiency.•A high specific capacitance of 943 F g−1 was achieved at charge and discharge current of 25 A g−1.
Biological sodium channels ferry sodium ions across the lipid membrane while rejecting potassium ions and other metal ions. Realizing such ion selectivity in an artificial solid-state ionic device ...will enable new separation technologies but remains highly challenging. In this work, we report an artificial sodium-selective ionic device, built on synthesized porous crown-ether crystals which consist of densely packed 0.26-nm-wide pores. The Na
selectivity of the artificial sodium-selective ionic device reached 15 against K
, which is comparable to the biological counterpart, 523 against Ca
, which is nearly two orders of magnitude higher than the biological one, and 1128 against Mg
. The selectivity may arise from the size effect and molecular recognition effect. This work may contribute to the understanding of the structure-performance relationship of ion selective nanopores.
Growing demand for clean and renewable energy resources has sparked intensive research on the development of an effective strategy to prepare non-noble metal electrocatalysts for oxygen evolution ...reaction (OER). Herein, we report a new type of N-doped carbon coated CoP particle/carbon nanotube composite (CNT-NC-CoP) has been synthesized by in situ nucleation and growth of ZIF-67 nanoparticles onto carbon nanotubes, which subsequently is treated with carbonization and phosphorization. Unique hierarchical structure endows as-obtained CNT-NC-CoP with high specific surface area, abundant exposed active sites, quick ion diffusion path, and good electrical conductivity, thus exhibiting the highest electrocatalytic capability with the low overpotential of 251 mV at the current density of 10 mA cm−2 and remaining long-term durability (overlapping LSV curve after 10 h). Besides, density functional theory (DFT) calculations reveal that CoOOH/graphene charged surfaces are more effective for facilitating intermediates adsorption and improving the corresponding catalytic activity.
Schematic illustration of the synthesis of N-doped carbon coated CoP particle/carbon nanotube composite, which has been prepared by in situ growth of ZIF-67 nanoparticles onto PDA-coated carbon nanotubes, subsequently being treated with carbonization and phosphorization. Display omitted
YOHCO3 colloidal particles with tunable size, composition, and optical properties were prepared, and they were used for the fabrication of amorphous photonic crystals’ (APCs) patterns through direct ...hand painting. YOHCO3 colloids were synthesized by a seeding growth method, in which the colloid size could be controlled by altering the seed amounts and the composition and optical properties can be altered via the doping of Eu3+. APCs’ films with bright, permanent, and tunable structural colors were prepared by the self-assembly of YOHCO3 colloids of different sizes. Multicolor patterns can be obtained quickly and efficiently by hand painting with the dispersion of YOHCO3 colloids as ink. An APCs’ pattern assembled from YOHCO3:Eu colloids is also fabricated, and the pattern shows blue structural color under natural light and bright red colors under illumination of UV light. The facile synthesis procedure, simple assembly process, and unique optical properties of the APCs make it valuable for practical applications such as structural color-based printing and anticounterfeiting.
Tailoring the electronic arrangement of graphene by doping is a practical strategy for producing significantly improved materials for the oxygen-reduction reaction (ORR) in fuel cells (FCs). Recent ...studies have proven that the carbon materials doped with the elements, which have the larger (N) or smaller (P, B) electronegative atoms than carbon such as N-doped carbon nanotubes (CNTs), P-doped graphite layers and B-doped CNTs, have also shown pronounced catalytic activity. Herein, we find that the graphenes doped with the elements, which have the similar electronegativity with carbon such as sulfur and selenium, can also exhibit better catalytic activity than the commercial Pt/C in alkaline media, indicating that these doped graphenes hold great potential for a substitute for Pt-based catalysts in FCs. The experimental results are believed to be significant because they not only give further insight into the ORR mechanism of these metal-free doped carbon materials, but also open a way to fabricate other new low-cost NPMCs with high electrocatalytic activity by a simple, economical, and scalable approach for real FC applications.
The fuel cell (FC), as a clean and high-efficiency device, has drawn a great deal of attention in terms of both fundamentals and applications. However, the high cost and scarcity of the requisite ...platinum catalyst as well as a sluggish oxygen reduction reaction (ORR) at the cathode in FC have become the greatest barrier to large-scale industrial application of FC. The development of novel non-precious metal catalysts (NPMC) with excellent electrocatalytic performance has been viewed as an important strategy to promote the development of FC. Recent studies have proven that metal free carbon materials doped with heteroatom (e.g. N, B, P, S or Se) have also shown striking electrocatalytic performance for ORR and become an important category of potential candidates for replacing Pt-based catalysts. This review summarizes recent achievements in heteroatom doped carbon materials as ORR catalysts, and will be beneficial to future development of other novel low-cost NPMCs with high activities and long lifetimes for practical FC applications.
► This review systematically summarizes recent achievements in heteroatom doped carbon materials as ORR catalysts. ► Some novel NPMCs with excellent electrocatalytic performance toward ORR are presented. ► Some problems and prospects involving doped carbon materials as ORR catalysts are discussed.
Environmentally friendly and efficient transition metal phosphide (TMP) electrocatalysts for oxygen evolution reaction (OER) are developed to meet the growing demand for clean energy. Here we report ...a novel and environmentally friendly strategy for the preparation of MOF-derived bimetallic phosphide embedded in the carbonaceous matrix (FeNiP/C). With 3-dimensional hollow barrel shape and high specific surface, FeNiP/C-900 performs excellent OER catalytic performance, reaching a current density of 10 mA cm−2 at an overpotential of 229 mV with a low Tafel slope of 74.5 mV dec−1. Meantime, we explore the thermal conversion mechanism of P-containing MOF and the compositional changes during heat treatment.
Schematic illustration represents the synthesis of FeNiP/C composite, which is prepared by the self-assembly of Ni2+, H3TPO, and dabco to form BMM-10 microcrystals, followed by the treatment of the Fe3+ etching and direct pyrolyzation. In-situ formed FeNiP nanoparticles anchored on the carbon layer with 3D hollow structure performs an enhanced electrocatalyst activity for OER. Finally, the transformation mechanism of this P-contained BMM-10 is also well explored. Display omitted
•A less toxic strategy to prepare porous MOF-derived transition metal phosphide nano-composites.•The as-obtained hollow FeNiP/C-900 nano-composite possesses the high electrocatalytic activity for OER.•The chemical bond and phase changes are discussed to form FeNiP/C nano-particles.
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