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Lightweight, strong and broadband microwave absorbents are urgently demanded for practical applications. Exploring magnetic/dielectric composites by anchoring magnetic nanostructures on lightweight dielectric carbon is an effective way, due to their possible good impedance matching condition. Herein, one-dimensional FeCo/C nanofibers are fabricated by electrospinning method and subsequent anoxic annealing treatment, which are used as difunctional magnetic/dielectric microwave absorbents. The nanofibers have a large aspect ratio, in which tiny magnetic FeCo nanocrystals are uniformly decorated in the amorphous dielectric C nanofibers. Benefiting from good impedance matching condition, enhanced microwave attenuation ability and synergistic effect between ferromagnetic FeCo and dielectric C, the FeCo/C nanofibers exhibit boosting microwave absorption performance, which is related to the absorber thickness and filling ratio. The optimal FeCo/C/paraffin composites with 40 wt% of functional fillers show a minimum reflection loss value of −59.9 dB with broad effective absorption bandwidth of 6.0 GHz at 13.2 GHz when the absorber thickness is only 2.6 mm. The FeCo/C nanofibers have a small density of only about 1.1 g/cm3, much smaller than the bulk FeCo (7.4–7.6 g/cm3). Owing to the characteristics of low density, strong absorption and broad effective absorption bandwidth, the FeCo/C nanofibers are promised to be good candidates as microwave absorbents. Image 1 • The FeCo/C nanofibers were prepared by electrospinning and annealing treatment. • The carbon nanofibers were uniformly decorated by tiny FeCo nanocrystals. • The FeCo/C nanofibers have a small density of only 1.1 g/cm3. • The absorption bandwidth of FeCo/C reaches 6.0 GHz with a thickness of 2.6 mm. • The FeCo/C composites show a minimum reflection loss value of −59.9 dB at 13.2 GHz. [ABSTRACT FROM AUTHOR]

Unlike temperature-controlled hydrogenation for synthesizing hydrogen storage materials, reactive milling of Mg crystal under hydrogen atmosphere for MgH 2 synthesis is often uncontrollable. For the first time, we try to understand the preparation of MgH 2 during the reactive ball milling in the perspective of energy conversion and structural evolution. High-energy ball milling can lead to basal slip of Mg crystal, which is controlled to disclose Mg(0001), thus further to enhance its hydriding reaction activity. To trigger the reaction of Mg hydriding without catalyst, the energy transferred by collisions in unit time should be over 148.1 kJ mol−1 according to DFT calculations. Due to structural modulation of Mg crystal, the synthesis of MgH 2 from Mg crystal under hydrogen atmosphere by high-energy ball milling can be divided into three periods, and can be optimized for the fine synthesis of MgH 2. This work is helpful for the controllable synthesis of MgH 2 during high-energy ball milling, and should also inspire how to select conditions to synthesize other functional materials. Image 1 • Energy conversion during high-energy ball milling can be regulated. • Controllable synthesis of MgH 2 can be achieved by regulating transfer energy. • Reactive milling of Mg under hydrogen atmosphere is composed of three periods. • Controllable structural evolution contributes to the fine synthesis of MgH 2. [ABSTRACT FROM AUTHOR]

Novel amorphous Fe 3 O 4 /FePO 4 /ZrO 2 ceramic coatings as solid acid with porous structure were successfully synthesized in the phosphate electrolyte containing K 2 ZrF 6 via plasma electrolytic oxidation (PEO) technique and characterized by scanning electron microscopy, X-ray diffraction and X-ray photoelectron spectroscopy. The surface acidic property was investigated by NH 3 -TPD method. The results showed that the pore size and the intensity of pore interconnection of amorphous Fe 3 O 4 /FePO 4 /ZrO 2 ceramic coating with solid acid property, increased with the increase of the K 2 ZrF 6 dosage from 0.5 g to 2.0 g in the phosphate electrolyte. The Fenton-like performance of PEO coating catalysts was investigated by degradation of phenol under circumneutral pH. It was found that phenol removal efficiency decreased with the adding of K 2 ZrF 6 amount from 0.5 g to 2.0 g except no catalytic activity of coating prepared without K 2 ZrF 6 , and Fenton-like PEO coating catalyst prepared with 0.5 g K 2 ZrF 6 exhibited a superior catalytic activity which could degrade phenol thoroughly within 2 min under circumneutral pH. The strong acid sites played a dominant role in enhancing the Fenton-like catalytic activity. The excellent catalytic activity of PEO coating prepared in the phosphate electrolyte containing K 2 ZrF 6 endowed it potential application in wastewater treatment. [ABSTRACT FROM AUTHOR]

Inferior specific capacity and sluggish redox kinetics are the most stubborn problems lithium-ion and lithium-sulfur batteries (LIBs and LSBs) are facing, respectively. Here we report a facile fabrication of self-supported hollow Co 3 O 4 @carbon nanotubes on carbon cloth (H-Co 3 O 4 @CNT/CC) through a mild pyrolysis-oxidation process. The additive- and binder-free H-Co 3 O 4 @CNT/CC shows excellent electrochemical performances as both LIBs and LSBs electrodes. As a robust integrated anode for LIBs, the areal capacities are 2.72 mAh cm−2 at the current density of 0.5 C over 1000 cycles. While as a durable cathode host for LSBs, favorable areal capacities of 2.37 mAh cm−2 are maintained with a low capacity decay of 0.11 % per cycle at the sulfur loading of 6 mg cm−2 and current density of 1 C after 400 cycles. Electrochemical technology, ex situ Raman spectroscopy and DFT calculations are performed to comprehensively analyze H-Co 3 O 4 @CNT/CC via thermodynamics and kinetics. It is demonstrated that the hierarchically hollow interior structure, strong adsorb ability of Co 3 O 4 toward polysulfides and three-dimensional (3D) inter-connected conductive carbon framework are responsible for the high areal capacity, fast redox kinetics and cycling durability. [Display omitted] • The integrated electrode possesses the merits of hollow nanostructured Co 3 O 4 and 3D inter-connected conductive network. • Electrochemical technology and DFT calculations are performed to comprehensively analyze H-Co 3 O 4 @CNT/CC. • H-Co 3 O 4 @CNT/CC delivers high areal capacities of 2.72 mAh cm-2 after 1000 cycles at 0.5 C as anode. [ABSTRACT FROM AUTHOR]

It is very significant to boost separation efficiency of photoinduced charge carriers and to extend absorption light range from ultraviolet light into visible light region for photocatalysts. Here, Ti 3 C 2 incorporation boosted the separation efficiency of photogenerated carriers of MoS 2 , extended absorption light region, heightened the absorption intensity of visible light, and enhanced photocatalytic stability. The rhodamine B (RhB) solution could be completely degraded using MoS 2 /Ti 3 C 2 under visible light after only 30 min. The comparing evaluation of photocatalytic activity signified that the reaction kinetics of RhB photodegradation over MoS 2 /Ti 3 C 2 increased 1.4 and 3 times under UV light and visible light irradiation, respectively. Experimental tests and density functional theory (DFT) calculation confirmed the formation of MoS 2 /Ti 3 C 2 Schottky junction, in which Ti 3 C 2 served as electron sink. The photogenerated electrons in MoS 2 easily transferred to Ti 3 C 2 phase due to driving force of built in electric field, which realized efficient separation of photocarriers and prolonged the life span of photoproduced holes. We sincerely hoped this catalyst could be widely applied in wastewater treatment field. The flower-like MoS 2 grew on lamellar Ti 3 C 2 to form MoS 2 /Ti 3 C 2 Schottky junction that easily promoted photogenerated charge separation. [Display omitted] • MoS 2 /Ti 3 C 2 Schottky junction was synthesized by a simple and low-cost method. • The photocatalytic activity of MoS 2 /Ti 3 C 2 was higher than that of benchmark MoS 2. • The boosted catalytic activity was interpreted via experiments and DFT calculation. [ABSTRACT FROM AUTHOR]