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[Display omitted] • An operando crystal-amorphous transformation of VOOH is demonstrated via in-situ / ex-situ structural analyses. • The unique crystal-amorphous transformation allows the obtained amorphous V 2 O 5 to achieve the high capacity, superior rate performance, and high energy and power densities. • The potentiality of cathode materials via operando crystal-amorphous transformation to achieve the enhanced zinc storage is confirmed. Aqueous zinc-ion batteries have obtained broad attention due to their high safety, eco-friendliness, and low cost. However, they are still in the developing stage considering the limited candidate of high-performance cathode materials. Furthermore, the intrinsic storage zinc mechanism is also needed to uncover. Here, we propose an operando crystal-amorphous transformation of tunnel-type VOOH and the obtained amorphous V 2 O 5 serves as a high-performance zinc-ion battery cathode. In-situ X-ray diffraction corroborates the unique operando crystal-amorphous transformation of VOOH during the initial charging process. X-ray photoelectron spectroscopy and transmission electron microscopy further demonstrate the element valence evolution and the lattice structure change, respectively. The operando electrochemical crystal-amorphous transformation allows the obtained amorphous V 2 O 5 to achieve the high capacity of ∼ 350.7 mAh g−1, rate performance (151.2 mAh g−1 at 6.4 A g−1), energy and power densities (137 Wh kg−1 at 6831 W kg−1), unveiling a promising approach of cathode materials via operando crystal-amorphous transformation to achieve the enhanced zinc storage. [ABSTRACT FROM AUTHOR]

A series of multicomponent Co 9 S 8 @MoS 2 nanohybrids derived from cobalt-doped polyoxometalate (Co-POMs) by modulating the precursor ratios of H 5 Mo 12 O 41 P (PMo 12) to Co(NO 3) 2 was synthesized and utilized as a bifunctional electrocatalyst for a non-Pt methanol oxidation reaction and overall water splitting in alkaline solution. In view of the importance of multifunctional catalysts that can drive different electrocatalytic reactions in the same electrolyte solution, we designed and prepared a series of multicomponent nanohybrids composed of Co 9 S 8 and MoS 2 derived from cobalt-doped polyoxometalate (Co-POMs) by one-pot calcination method. The obtained Co 9 S 8 @MoS 2 nanohybrids were composed of Co 9 S 8 , MoS 2 , Co-Mo-S phases and assembled nanosheets, and therefore were explored as trifunctional electrocatalysts for hydrogen evolution reaction, oxygen evolution reaction, and methanol oxidation reaction (MOR) in an alkaline medium. The nanostructure and chemical components of the series of Co 9 S 8 @MoS 2 nanohybrids can be modulated by changing the mole ratios of H 5 Mo 12 O 41 P to Co(NO 3) 2 precursor. Compared with the sole component and other reported Co 9 S 8 @MoS 2 nanohybrids, the Co 9 S 8 @MoS 2 nanohybrid prepared from the 1:1 ratio of PMo 12 and Co(NO 3) 2 exhibited superior MOR catalysis efficiency (121.4 mA cm−2) and an extremely low overpotential (1.49 V) for overall water splitting at a current density of 10 mA cm−2 owning to the effective synergism among Co 9 S 8 , MoS 2 , and Co-Mo-S phase. Overall, this study provides a feasible approach to developing efficient and stable trifunctional bimetal electrocatalysts for clean-energy applications. [ABSTRACT FROM AUTHOR]

• Zeolitic imidazolate framework-8 (Zif-8) was prepared by a facile microwave hydrothermal method. • The N doped ZnO was synthesized by one-step controllable pyrolysis of Zif-8. • The N doped ZnO exhibited a higher photocatalytic degradation of methylene blue (MB) under solar-simulated light. The precursor particles were successfully prepared by a facile microwave hydrothermal method. Compared with solvothermal and precipitation method, microwave hydrothermal method can greatly shorten the reaction time and increase the product yields. Nitrogen (N) doped zinc oxide (ZnO) nanoparticles were derived via one-step controllable pyrolysis of zeolitic imidazolate framework-8 (Zif-8) precursors under 550 °C. The powder X-ray diffraction (XRD) analysis, elemental mapping image, energy dispersive spectrometry (EDS) spectra and X-ray photoelectron spectroscopy (XPS) analysis proved that Zif-8 particles were converted to ZnO and the N atoms were successfully doped into ZnO lattice. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) results demonstrated that N doped ZnO retained the morphology of Zif-8 with a particle size of approximately ~70 nm and the UV–visible diffuse reflectance spectra (UV–vis DRS) showed that the as-prepared N doped ZnO possessed a lower band gap (3.16 eV) than commercial ZnO (3.26 eV). The photocatalytic activities of the as-prepared samples were evaluated by the degradation rate of methylene blue (MB) upon irradiation with solar-simulated light. The photocatalytic degradation efficiency of N doped ZnO was 95.3% after 80 min illumination, which was much higher than that of other samples prepared by other methods. Quenching tests proved that the photo-generated holes (h+) played a main role in the photodegradation of MB under solar-simulated light irradiation. [ABSTRACT FROM AUTHOR]

Cellulose aerogels are a new category of high-efficiency adsorbents for treating oil spills and water pollution. However, the hydrophilic properties and recyclability of aerogels after adsorption hamper developments and applications. Combining both hydrophobic and magnetic properties are expected to improve their adsorption capacity and functionality. In this study, the effect of oleic acid (OA) and nanomagnetite on the preparation of magnetic nanocellulose aerogels (called as NCA/OA/Fe 3 O 4) by a mechanical mixing combined with freeze-drying method have been investigated. It has been found that the optimal condition for fabricating this NCA/OA/Fe 3 O 4 aerogel is 0.4 wt% nanocellulose, 3 mg mL−1 OA and 0.5 wt% Fe 3 O 4 in the aqueous solution. This aerogel has a very low density of 9.2 mg cm−3 and demonstrates a high adsorption capacity of 68.06 g g−1 for cyclohexane. In addition, this aerogel adsorbent demonstrates an excellent magnetic responsivity and can be easily recycled by a permanent magnet after adsorption. As a consequence, this hydrophobic magnetic NCA/OA/Fe 3 O 4 aerogel is promising not only for easy oil and organic solvent adsorption but also potentially for other magnetic related applications. [ABSTRACT FROM AUTHOR]

• B-doping carbon nanodots (B-C-dots) were decorated on the surface of C 3 N 4. • Effectively enhanced photocatalytic activity was observed on B-C-dots decorated C 3 N 4. • The type-II heterojunction of C 3 N 4 and B-C-dots improved the photocatalytic activity. • Effect of B doping level of C-dots on the photocatalytic activity was investigated. Decorating electron-accepting materials on carbon nitride (C 3 N 4) is a promising strategy to construct heterostructure catalysts for improved photocatalytic abilities. In this study, B-doped carbon-dots (B-C-dots) decorated C 3 N 4 (C 3 N 4 /B-C-dots) catalysts were fabricated through the surface deposition. The benefits from integration of B-C-dots and C 3 N 4 are four folds: (i) increasing surface area; (ii) improving visible light absorption; (iii) promoting the transfer of photoinduced carriers; and (iv) reducing the recombination of photoinduced carriers. The optimum photocatalytic activity of B-C-dots/C 3 N 4 for Rhodamine B (Rh B) (or tetracycline hydrochloride (TC)) degradation was about 7.21 (6.56) and 4.80 (4.35) times higher than that of C 3 N 4 and C-dots/C 3 N 4 , respectively, exhibiting both remarkable stability and repeatability. Moreover, enhanced photocatalytic activity of C 3 N 4 /B-C-dots could also be attributed to the type-II heterojunction formed between C 3 N 4 and B-C-dots caused by B doping. [ABSTRACT FROM AUTHOR]

• Cobalt nanoparticles anchored porous N-doped carbon nanosheets (Co@PNCS) were fabricated and tested as high-performance cathode catalysts for Li-O 2 batteries. • The capacity as high as 11,329 mAh g−1, with an extended cycle life of more than 120 cycles were reported. • DFT calculations indicated the active Co sites with a more stable binding ability to discharge Li 2 O 2 products than that of the active N sites responsible for this enhancement. Cobalt (Co) nanoparticles anchored porous N-doped carbon nanosheets (Co@PNCS) were fabricated using a facile one-pot pyrolysis route and tested as high-performance cathode catalysts for Li-O 2 batteries. The hierarchical structure was made of cobalt nanoparticles distributed in the crumpled porous carbon nanosheets. Uniformly distributed and exposed cobalt nanoparticles in the PNCS exhibited a higher electrocatalytic activity compared to Co nanoparticles anchored nitrogen-carbon materials (Co-N-C). Density function theory (DFT) calculations based on the interfacial model demonstrated that the active Co sites exhibited a more stable binding ability to discharge Li 2 O 2 products than that of the active N sites, and Li 2 O 2 could be reversibly formed and decomposed during cycling. Owing to optimal loadings of Co nanoparticles (16.03 wt%), the Co@PNCS-2 cathode exhibited a high specific capacity of 11,329 mAh g−1 and extended cycling life of 120 cycles, highlighting the great potential as cathode catalysts for Li-O 2 batteries. [ABSTRACT FROM AUTHOR]

Low photocatalytic efficiency of visible light and fast recombination of photo-generated carriers are two challenges facing the applications of photocatalyst sterilant zinc oxide (ZnO). Meanwhile, both light and dark photocatalytic activities are important. It is of great theoretical and practical significance to construct a day-night photocatalytic antibacterial material, which is beneficial to the effective use of energy and to tackle the limitation of using photocatalytic bacteriostat. ZnO nanoflowers decorated vanadium pentoxide (V 2 O 5) nanowires heterojunction (ZVH) was firstly fabricated using a facile water-bathing method. The designed ZVH structure efficiently produced abundant reactive oxygen species (ROS) in both light and darkness. It yielded 99.8% and 99.0% of antibacterial rate against S. aureus due to oxidative stress induced by ROS in light and darkness, respectively. The generation of ROS played a major role in the antibacterial activities against S. aureus under both light and dark conditions. The prepared ZVH with improved antibacterial properties provides an alternative for day-night antibacterial agents. [ABSTRACT FROM AUTHOR]