Latest ArticlesAqueous zinc ion batteries (AZIBs) with the merits of low cost, low toxicity, high safety, environmental benignity as well as multi-valence properties as the large-scale energy storage devices demonstrate tremendous application prospect. However, the explorations for the most competitive manganese-based cathode materials of AZIBs have been mainly limited to some known manganese oxides. Herein, we report a new type of cathode material NH4MnPO4·H2O (abbreviated as AMPH) for rechargeable AZIBs synthesized through a simple hydrothermal method. An in-situ electrochemical strategy inducing Mn-defect has been used to unlock the electrochemical activity of AMPH through the initial charge process, which can convert poor electrochemical characteristic of AMPH towards Zn2+ and NH4+ into great electrochemically active cathode for AZIBs. It still delivers a reversible discharge capacity up to 90.0 mAh/g at 0.5 A/g even after 1000th cycles, which indicates a considerable capacity and an impressive cycle stability. Furthermore, this cathode reveals an (de)insertion mechanism of Zn2+ and NH4+ without structural collapse during the charge/discharge process. The work not only supplements a new member for the family of manganese-based compound for AZIBs, but also provides a potential direction for developing novel cathode material for AZIBs by introducing defect chemistry.
Crystalline porous ionic salts (CPISs) represent a new type of porous materials constructed by electrostatic interaction, however, synthesis of CPISs bearing pre-designed functionality while exhibiting permanent porosity is still challenging. Herein we report the facile synthesis of a series of CPISs 1-3 built from photocatalytic-active polyoxometalate (POM) clusters and cationic Zr-based capsules, which showed open porous frameworks with BET surface area up to 33 m2/g and high activity and selectivity for photo-driven aerobic oxidation of alcohols to aldehydes. Compared with the pristine POM cluster {W10}, 1 can promote the reaction in much higher efficiency due to the concerted catalysis of preinstalled {W10} and Zr-based capsule together with open channels. This work highlights the advantage of CPISs as porous heterogeneous catalysts in organic transformation, and may shed light on the rational design of more delicate CPISs-derived functional materials.
Metal-organic frameworks (MOFs) have showed high promise in CO2-electroreduction, yet their generally insufficient conductivity or low electron-transfer efficiency have largely restricted the wide-spread applications. Herein, fullerene molecules (i.e., C60 and C70) have been successfully introduced into the pore-channels of a Co-porphyrin based MOF through a facile strategy. Thus-obtained hybrid materials present higher electron-transfer ability, enhanced CO2 adsorption-enthalpy and CO2 electroreduction activity. Notably, the charge transfer resistance (Rct) of C60@MOF-545-Co is almost 5 times lower of than that of MOF-545-Co, as well as 1.5 times increased for the CO2 adsorption enthalpy. As expect, the FECO of C60@MOF-545-Co (97.0%) is largely higher than MOF-545-Co (70.2%), C60@MOF-545 (19.4%), C60 (11.5%) and physical mixture (70.3%) and presented as one of the best CO2 electroreduction catalysts reported in H-cell system. The facile strategy would give rise to new insight into the exploration of powerful MOF-based hybrid materials in high-efficiency CO2 electroreduction.
Sodium-ion batteries (SIB) have attracted widespread attention in large-scale energy storage fields owing to the abundant reserve in the earth and similar properties of sodium to lithium. Biomass-based carbon materials with low-cost, controllable structure, simple processing technology, and environmental friendliness tick almost all the right boxes as one of the promising anode materials for SIB. Herein, we present a simple novel strategy involving tea tomenta biomass-derived carbon anode with enhanced interlayer carbon distance (0.44 nm) and high performance, which is constructed by N, P co-doped hard carbon (Tea-1100-NP) derived from tea tomenta. The prepared Tea-1100-NP composite could deliver a high reversible capacity (326.1 mAh/g at 28 mA/g), high initial coulombic efficiency (ICE = 90% at 28 mA/g), stable cycle life (262.4 mAh/g at 280 mA/g for 100 cycles), and superior rate performance (224.5 mAh/g at 1400 mA/g). Experimental results show that the excellent electrochemical performance of Tea-1100-NP due to the high number of active N, P-containing groups, and disordered amorphous structures provide ample active sites and increase the conductivity, meanwhile, large amounts of microporous shorten the Na+ diffusion distance as well as quicken ion transport. This work provides a new type of N, P co-doped high-performance tomenta-derived carbon, which may also greatly promote the commercial application of SIB.
A branched core-shell nanosphere composed of an anatase TiO2 (a-TiO2) core and a TiO2 nanobranch shell with gradient-doped N (a-TiO2@N-TiO2) is synthesized by a simple in situ doping method, in which mixed crystal anatase-rutile TiO2 (ar-TiO2) nanosphere is first prepared by oxidizing Ti using H2O2, and then is etched by NH3·H2O to form (NH4)2TiO3 nanobranches, which is converted into a-TiO2@N-TiO2 following an ambient annealing process. The diameter of a-TiO2 core is ~500 nm, and the thickness of N-TiO2 branched shell is ~100 nm with gradually increased N concentration from the bottom to the edge. Ultra-thin amorphous coating layers on the branches are also observed. The morphology of the composites could be further tuned by the amount of NH3·H2O, and its effect on the photocatalytic performance is also investigated. The optimized a-TiO2@N-TiO2 shows an outstanding hydrogen evolution rate of 308.1 µmol g−1 h−1 under air mass (AM) 1.5 illumination, and also exhibits highly active in photocatalytic degradation of various refractory organic pollutants, including organic dyes, phenols, antibiotics, and personal care products, with removal ratios higher than 96% after 2 h operation. This can be due to the gradient-doped N-TiO2 nanobranches, which not only provide bending band structure and defect level derived from the N impurities and O vacancies, resulting the formation of n-n+ heterojunctions to improve the charge separation, but also enhance the charge transfer at the liquid-solid interface due to the numerous nanobranches and amorphous coating layers.
Self-doping cathode interfacial layers (CILs) with both favorable electron injection and transport characteristics meet the key requirement for realizing high-performance optoelectronic devices with simplified structures. Herein, four different polypyridinium salts with tunable backbones, side chains and counter-ions are elaborately designed to afford them desirable film-forming property, polarity, structural rigidity and self-doping feature. All-solution-processed red quantum dot light-emitting diodes (QLEDs) employing them as bifunctional CILs render remarkably improved device performances in contrast to the typical CIL material of poly[(9,9-bis(30-(N,N-dimethylamino)propyl)-2,7-fluorene)-alt-2,7-(9,9-dioctylfluorene)] (PFN). The maximum external quantum efficiency of 2.74% achieved in this work represents one of the best values among the all-solution-processed QLEDs with individual organic CILs.
Quaternary approach has been receiving more and more attention due to its effectiveness in improving solar cell performance, while synthesis/selection of the fourth component is yet a key issue. Herein, we report a chlorinated phthalimide based donor polymer (namely PhI-Cl) having an ultra-wide bandgap (2.10 eV) and a deep HOMO (−5.58 eV) level. Addition of PhI-Cl as the third component of PM6:Y6 and the fourth of PM6:Y6:PC71BM increases both hole and electron mobilities and gives rise to more balanced charge carriers mobilities. Both the short-circuit current-density and fill-factor are increased and open-circuit voltage is well maintained, delivering 17.0% and 18.1% efficiencies, respectively. These results demonstrate that chlorination on the side thiophene of phthalimide-based donor polymer is a way to make deep HOMO and ultra-wide bandgap donor polymer guest used for highly efficient ternary and quaternary strategies.
The layered heterometallic halide perovskites, as a newly explored material, have attracted great scientific attention. As one of the representatives of perovskite, lead-free or lead-substituted perovskite materials are widely applied in photovoltaic, sensors, catalysis, detectors and other fields. Therefore, it is urgent to carry out more systematic exploration and expand applicable preresearch, so as to make more interesting discoveries in this new hot spot. As an interesting candidate, heterometallic compounds will introduce more structural adjustability and novel physical properties, which is the main feature to be selected as the research hotspot. Here, we reported a lead-free bilayer heterometallic Ruddlesden-Popper (RP) type perovskite, [(MACH)2CsAgBiBr7] (MACH = cyclohexanemethylamine), which possesses a reversible phase transition at 379.6 K/375.1 K during heating-cooling cycle. Besides, it exhibits reddish-brown light emission under 365 nm, meanwhile, CIE chromaticity coordinate is (0.32, 0.45) on the yellow side and correlated color temperature is about 6000 K. Moreover, both the experimental data and theoretical calculation results suggest that [(MACH)2CsAgBiBr7] shows indirect semiconducting characteristics. In summary, this work will inspire the design of lead-free heterometallic perovskite materials for the application of sensors and light-emitting diodes (LEDs) fields.
Conjugated microporous polymers (CMPs) with tunable bandgaps have attracted increasing attention for photocatalytic hydrogen evolution. However, the synthesis of CMPs usually needs expensive metal-based catalysts. Herein, we report a metal-free synthetic route to fabricate pyridyl conjugated microporous polymers (PCMPs) via a condensed polymerization between aldehyde and aryl ketone monomers. The PCMPs show widely tunable specific surface areas (347–418 m2/g), which were controlled via changing the used monomers. The PCMPs synthesized using monomers of dialdehyde and diacetylbenzene (diacetylpyridine) in the presence of pyridine exhibited the highest visible-light driven hydrogen evolution rate (9.56 µmol/h). These novel designed PCMPs provide wide adaptability to current materials designed for high-performance photocatalysts in different applications.
Due to its low cost and easy availability, the pitch is considered a promising precursor for soft carbon anodes. However, pitch-derived soft carbon shows a high graphitization degree and small interlayer spacing, resulting in its much lower sodium storage performance than hard carbon. We propose a novel pre-oxidation strategy to introduce additional oxygen atoms into the low-cost soft carbon precursor pitch to fabricate a defect-rich and large-interlayer spacing hard carbon anode (HPP-1100). Compared with the direct pyrolysis of pitch carbon, the sodium storage capacity of HPP-1100 is significantly improved from 120.3 mAh/g to 306.7 mAh/g, with an excellent rate and cycling capability (116.5 mAh/g at 10 C). Moreover, when assorted with an O3-Na(NiFeMn)1/3O2 cathode, the full cell delivers a high reversible capacity of 274.0 mAh/g at 0.1 C with superb cycle life. This work provides a new solution for realizing the application of low-cost pitch anodes in Na-ion batteries.
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
