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[Display omitted] • Fe 3 O 4 nanoparticles/RGO sandwich composites were successfully prepared via a facile route. • This simple and convenient synthesis strategy consists of blast drying and roasting. • The content of Fe 3 O 4 nanoparticles in RGO nanosheets can be widely regulated. • The Fe 3 O 4 /RGO sandwich composites exhibit excellent microwave absorption performance. • This facile route to fabricate sandwich structure offers a new idea for designing graphene-based composites. Component regulation and microstructure design are two effective strategies to adjust electromagnetic parameters and improve the microwave absorption performance of materials. In this study, a facile synthesis strategy consisting of ultrasonic dispersion, blast drying, and roasting is proposed to build a sandwich-like graphene-based absorbent, in which Fe 3 O 4 nanoparticles with adjustable content are sandwiched uniformly between reduced graphene oxide nanosheets. The sandwich structure can form multiple interfaces, prevent the aggregation of nanoparticles, facilitate interface polarization, and endow the material with multiple electromagnetic loss mechanisms, which is very beneficial for impedance matching and microwave attenuation. Notably, the effective absorption bandwidth achieves 5.7 GHz, and the minimum reflection loss value is −49.9 dB. In addition, the synthesis process is simple and suitable for large-scale production and possible industrial applications. Thus, this facile route to fabricate sandwich-like graphene-based absorbents provides new ideas and approaches for designing new graphene-based nanocomposites. [ABSTRACT FROM AUTHOR]

Carbon-based microwave-absorbing materials with a low cost, simple preparation process, and excellent microwave absorption performance have important application value. In this paper, biomass-based carbon fibers were prepared using cotton fiber, hemp fiber, and bamboo fiber as carbon sources. Then, the precise loading of NiFe2O4 nanoparticles on biomass-based carbon fibers with the loading amount in a wide range was successfully realized through a sustainable and low-cost route. The effects of the composition and structure of NiFe2O4/biomass-based carbon fibers on electromagnetic parameters and electromagnetic absorption properties were systematically studied. The results show that the impedance matching is optimized, and the microwave absorption performance is improved after loading NiFe2O4 nanoparticles on biomass-based carbon fibers. In particular, when the weight percentage of NiFe2O4 nanoparticles in NiFe2O4/carbonized cotton fibers is 42.3%, the effective bandwidth of NiFe2O4/carbonized cotton fibers can reach 6.5 GHz with a minimum reflection loss of −45.3 dB. The enhancement of microwave absorption performance is mainly attributed to the appropriate electromagnetic parameters with the ε' ranging from 9.2 to 4.8, and the balance of impedance matching and electromagnetic loss. Given the simple synthesis method, low cost, high output, and excellent microwave absorption performance, the NiFe2O4/biomass-based carbon fibers have broad application prospects as an economic and broadband microwave absorbent. [ABSTRACT FROM AUTHOR]

Multi-component design and microstructural regulation are commonly used strategies by researchers to improve the microwave absorption performance of materials, and it is essential to simultaneously explore sustainable and economical raw materials as well as simple preparation methods. In this study, the economical and sustainable bamboo fibers were used as a carbon source and template, and the CoFe alloy/carbonized bamboo fibers with different content were successfully prepared by the impregnation method and calcination method by controlling the nitrate concentration and calcination temperature. The analysis results display that the appropriate CoFe alloy content on carbonized bamboo fibers with nanopores can effectively improve the electromagnetic impedance matching and electromagnetic loss, resulting in excellent microwave absorption performance. The effective bandwidth almost simultaneously covers the X-band and Ku-band. This study not only facilitates the resource utilization of plant fibers, but also provides a new idea for the research of inexpensive, lightweight, and broadband microwave-absorbing materials. [Display omitted] • CoFe alloy/carbonized bamboo fibers were successfully fabricated. • Natural bamboo fibers were used to design new carbon-based microwave-absorbing materials. • The design route is simple and universally applicable. • The CoFe/carbonized bamboo fibers exhibit excellent microwave absorption in X-band and Ku-band. • The balance of impedance matching and electromagnetic loss makes important contribution. [ABSTRACT FROM AUTHOR]

Abstract Aiming at the disadvantages of high cost, complex processes, and low yield of carbon-based microwave absorbing materials. In this study, Co/C fibers were successfully prepared by using low-cost cotton as carbon source. The synthetic route was a flexible two-step approach consisting of immersion and subsequent carbothermal reduction in N 2 atmosphere. By means of controlling the Co(NO3)2·6H2O concentration and calcination temperature, Co nanoparticles with different loading amount and particle size were uniformly dispersed along the cotton-based carbon fibers. The Co loading amount, calcination temperature, and filling rate on electromagnetic parameters and microwave absorption performance were systematically studied. Among the Co/C fibers obtained at different Co(NO3)2·6H2O concentration and calcination temperatures, the Co/C fibers synthesized at 600 °C with 0.5 M Co(NO 3) 2 ·6H 2 O exhibited the best microwave absorption performance. The reflection loss (RL) values less than −10 dB were obtained in the frequency range of 11.3–18 GHz, which covered the entire Ku-band (from 12 to 18 GHz). Such excellent microwave absorption performance was attributed to the synergistic effect of dielectric loss, magnetic loss, and good impedance matching. Owing to the characteristics of cost-effective synthetic strategy, low density, and good microwave absorption, the Co/C fibers are highly promising as economic and broadband microwave absorbent. Graphical abstract Image 1 Highlights • Co/C fibers were successfully prepared by using low-cost cotton as carbon source. • The content and particle size of Co nanoparticles in Co/C fibers can be regulated. • The Co/C fibers exhibited excellent microwave absorption in the entire Ku-band. • The effective bandwidth of RL less than −10 dB can reach up to 6.7 GHz. [ABSTRACT FROM AUTHOR]

Since electromagnetic pollution is becoming more and more serious, novel composite microwave absorbents are gaining much attention. Here, Co 3 Fe 7 /C core–shell microspheres for microwave absorption were synthesized for the first time. At first, hollow CoFe 2 O 4 microspheres were prepared via a solvothermal method at 200 °C for 15 h. Then CoFe 2 O 4 -hydrochar microspheres were synthesized by hydrothermal method in an aqueous glucose solution containing hollow CoFe 2 O 4 microspheres. After annealed under Ar atmosphere at 500 °C, the CoFe 2 O 4 -hydrochar microspheres were converted into CoFe 2 O 4 –Co 3 Fe 7 /C microspheres. Co 3 Fe 7 /C core–shell microspheres came into being after annealed at 600 °C. Both the CoFe 2 O 4 –Co 3 Fe 7 nanoparticles and Co 3 Fe 7 nanoparticles were encapsulated in the carbon shells, and the microsphere morphology could be retained during the carbothermal process. Especially, the core–shell structure caused that the density of the Co 3 Fe 7 /C microspheres was below 2 g/cm 3 . Resulting from the synergistic effect of Co 3 Fe 7 nanoparticles and partially graphitized carbon, the minimum reflection loss (RL) of Co 3 Fe 7 /C microspheres was as low as −44.4 dB obtained with 1.6 mm thickness. Owing to the characteristics of low density and good microwave absorption, the Co 3 Fe 7 /C core–shell microspheres could be used as a lightweight and highly efficient microwave absorbent. [ABSTRACT FROM AUTHOR]

Since electromagnetic pollution is becoming more and more serious, the lightweight and highly efficient microwave absorbents are urgently needed to absorb unwanted electromagnetic microwaves. In this work, single-crystal octahedral CoFe 2 O 4 nanoparticles with the diameter of about 20–25 nm were successfully incorporated into the porous carbon balls (CB) via a one-step hydrothermal method. The incorporation of the CoFe 2 O 4 nanoparticles into CB reduced the dielectric loss and increased the magnetic loss, resulting in better impedance matching. When the CoFe 2 O 4 content in CoFe 2 O 4 /CB composites was 10 wt.%, the minimum reflection loss (RL) was as low as −37.2 dB, and the frequency band of RL below −10 dB was 12.9–17.1 GHz obtained with 1.5 mm thickness. This excellent microwave absorption performance was much better than that of the pure octahedral CoFe 2 O 4 nanoparticles, CB, and CoFe 2 O 4 /CB composites with CoFe 2 O 4 content of 8.5 wt.%. Owing to the low density of 1.1–1.2 g/cm 3 and good microwave absorption, the CoFe 2 O 4 /CB composite can meet the multiple requirements of microwave absorbent. [ABSTRACT FROM AUTHOR]

In this work, monodisperse hollow cobalt ferrite (CoFe 2 O 4 ) microspheres with mean diameter of 150 nm and shell thickness of 50 nm have been successfully prepared via a one-pot solvothermal method. In order to improve the microwave absorption, a thermal reduction process was designed to synthesize hollow CoFe 2 O 4 –Co 3 Fe 7 microspheres. Scanning electron microscopy and transmission electron microscopy images showed that the CoFe 2 O 4 –Co 3 Fe 7 microspheres retained hollow structure. Microwave absorption results revealed that hollow CoFe 2 O 4 –Co 3 Fe 7 microspheres exhibited much stronger electromagnetic absorption than the original hollow CoFe 2 O 4 microspheres. Most importantly, when the sample thickness was 1.3 mm, the reflection loss (RL) less than −10 dB was obtained in the frequency range of 12.5–17.7 GHz, which nearly covered the entire Ku-band. When the sample thickness increased to 2 mm, the minimum RL was as high as −41.6 dB with the effective bandwidth (the bandwidth of RL at −10 dB) of 3 GHz. The enhanced microwave absorption was attributed to efficient complement between dielectric loss and magnetic loss. These results indicated that the hollow CoFe 2 O 4 –Co 3 Fe 7 microspheres could be used as a new candidate for microwave absorbents, especially in Ku-band. [ABSTRACT FROM AUTHOR]

A simple low-cost hydrothermal method has been developed to fabricate uniformly dispersed octahedral Fe 3O 4 nanoparticles with tunable size. The particle size can be reduced to 20–30 nm under the effect of phosphate, meanwhile, the edetate disodium can improve the dispersivity of particles. High-resolution transmission electron microscope showed that the octahedral Fe 3O 4 nanoparticle was enclosed by eight (111) planes. Octahedral γ-Fe 2O 3 nanoparticles were obtained by reoxidizing the as-synthesized Fe 3O 4 nanoparticles. The microwave absorption properties of the octahedral Fe 3O 4 and γ-Fe 2O 3 nanoparticles were measured in the frequency range of 2–18 GHz. A minimum reflection loss of −28 dB was observed at 8.6 GHz for octahedral Fe 3O 4 nanoparticles. [ABSTRACT FROM AUTHOR]

In this work, brookite TiO2 nanocrystals with co-exposed {001} and {120} facets (pH0.5-T500-TiO2 and pH11.5-T500-TiO2), rutile TiO2 nanorod with exposed {110} facets and anatase TiO2 nanocrystals with exposed {101} facets (pH3.5-T500-TiO2) and {101}/{010} facets (pH5.5-T500-TiO2, pH7.5-T500-TiO2 and pH9.5-T500-TiO2) were successfully synthesized through a one-pot solvothermal method by using titanium (V) iso-propoxide (TTIP) colloidal solution as the precursor. The crystal structure, morphology, specific surface area, surface chemical states and photoelectric properties of the pHx-T500-TiO2 (x = 0.5, 1.5, 3.5, 5.5, 7.5, 9.5, 11.5) were characterized by powder X-ray diffraction (XRD), field scanning transmission electron microscopy (FESEM), transmission electron microscopy (TEM), high-resolution TEM (HRTEM), nitrogen adsorption instrument, X-ray photoelectron spectroscopy (XPS), UV-Visible diffuse reflectance spectra and electrochemical impedance spectroscopy (EIS). The photocatalytic activity performance of the pHx-T500-TiO2 samples was also investigated. The results showed that as-prepared pH3.5-T500-TiO2 nanocrystal with exposed {101} facets exhibited the highest photocatalytic activity (95.75%) in the process of photocatalytic degradation of methyl orange (MO), which was 1.1, 1.2, 1.2, 1.3, 1.4, 1.6, 10.7, 15.1 and 27.8 fold higher than that of pH5.5-T500-TiO2 (89.47%), P25-TiO2 (81.16%), pH9.5-T500-TiO2 (79.41%), pH7.5-T500-TiO2 (73.53%), pH0.5-T500-TiO2 (69.10%), CM-TiO2 (61.09%), pH11.5-T500-TiO2 (8.99%), pH1.5-T500-TiO2 (6.33%) and the Blank (3.44%) sample, respectively. The highest photocatalytic activity of pH3.5-T500-TiO2 could be attributed to the synergistic effects of its anatase phase structure, the smallest particle size, the largest specific surface area and exposed {101} facets. [ABSTRACT FROM AUTHOR]

[Display omitted] • Fe, Co, or Ni nanoparticles/RGO nanosheets sandwich structure was fabricated. • The content of Fe, Co, or Ni nanoparticles in RGO nanosheets can be widely regulated. • The facile self-assembly and thermal reduction techniques are universally applicable. • The Co/RGO nanosheets exhibit excellent microwave absorption in X-band and Ku-band. • The interfaces between RGO nanosheets and Co nanoparticles make important contribution to the microwave absorption. The application of graphene-based composites as microwave absorbing materials still has some problems despite optimistic outlook. In this work, sandwich-like Fe, Co, or Ni nanoparticles/reduced graphene oxide (RGO) composites were successfully fabricated via self-assembly and thermal reduction techniques. The characterization results of XRD, Raman spectroscopy, XPS, SEM, TEM, and thermogravimetric analysis showed that the Fe, Co, and Ni nanoparticles were wrapped by flexible RGO nanosheets, showing sandwich structure. Moreover, the loading amounts of Fe, Co, and Ni nanoparticles were further controlled in a wide range. As expected, this unique sandwich structure can not only reduce the agglomeration of magnetic metal nanoparticles and RGO nanosheets, but also improve the impedance matching and the relaxation loss, achieving an attractive microwave absorption performance. For Co/RGO composites, the value of the minimum reflection loss is –50.60 dB, and the effective absorption bandwidth (RL ≤ –10 dB) can cover the entire X-band and Ku-band with a low filling ratio of 25%. Moreover, the synthesis process is simple and does not require complicated equipment and a variety of chemical reagents, which are suitable for large-scale production and possible industrial applications. The present work provides a good design and fabricating avenue for new graphene-based nanocomposites. [ABSTRACT FROM AUTHOR]

[Display omitted] Zinc-iodine batteries (ZIBs) have been recognized as a promising energy storage device due to their high energy density, low cost and environmental friendliness. However, the development of ZIBs is hindered by the shuttle effect of polyiodides which results in capacity degradation and poor cycling performance. Inspired by the ability of starch to form inclusion compounds with iodine, we propose to use a starch gel on the cathode to suppress the shuttle of polyiodides. Herein, porous carbon is utilized as a host for iodine species and provides an excellent conductive network, while starch gel is used as another host to suppress polyiodides shuttle, resulting in improved battery performance. The test results demonstrate that the conversion between I−/I 2 /I 3 − in the cathode and the effective inclusion role of starch suppress the shuttle of polyiodides during the charging process. Meanwhile, based on the electrochemical tests and theoretical DFT calculations, it is found that starch has a stronger ability to adsorb polyiodides compared to carbon materials, which enables effective confinement of polyiodides. The ZIBs used the cathode with starch gel exhibit high coulombic efficiency (>95 % at 0.2 A/g) and low self-discharge (86.8 % after resting for 24 h). This strategy is characterized by its simplicity, low cost and high applicability, making it significant for the advancement of high-performance ZIBs. [ABSTRACT FROM AUTHOR]

Abstract: Efficient catalysts are required to promote oxygen reduction reaction (ORR) in order to implant ORR‐involved clean energy technologies such as fuel cells and metal‐air batteries. In this study, (111) facet‐exposed CoFe2O4 nano‐octahedrons crystals (NOCs) were grown on graphene via facile hydrothermal method and investigated as catalyst for ORR. The as‐made CoFe2O4 NOCs‐graphene composite exhibits very high activity towards ORR, meanwhile, excellent durability and very good tolerance to methanol were observed, which verifies the importance of exposing active facets of non‐precious metal‐based catalysts and also demonstrates its high potentials of replacing precious Pt for practical applications. [ABSTRACT FROM AUTHOR]

Biomass-derived hard carbon materials are considered as the most promising anode materials for sodium-ion batteries (SIBs) due to their abundant sources, environmental friendliness, and excellent electrochemical performance. Although much research exists on the effect of pyrolysis temperature on the microstructure of hard carbon materials, there are few reports that focus on the development of pore structure during the pyrolysis process. In this study, corncob is used as the raw material to synthesize hard carbon at a pyrolysis temperature of 1000~1600 °C, and their interrelationationship between pyrolysis temperature, microstructure and sodium storage properties are systematically studied. With the pyrolysis temperature increasing from 1000 °C to 1400 °C, the number of graphite microcrystal layers increases, the long-range order degree rises, and the pore structure shows a larger size and wide distribution. The specific capacity, the initial coulomb efficiency, and the rate performance of hard carbon materials improve simultaneously. However, as the pyrolysis temperature rises further to 1600 °C, the graphite-like layer begins to curl, and the number of graphite microcrystal layers reduces. In return, the electrochemical performance of the hard carbon material decreases. This model of pyrolysis temperatures–microstructure–sodium storage properties will provide a theoretical basis for the research and application of biomass hard carbon materials in SIBs. [ABSTRACT FROM AUTHOR]

Summary: Heteroatom doping could markedly enhance the properties of carbon materials. For the precursor with nitrogen (N) heteroatom, it is difficult to fix its own N heteroatom in target products to the maximum extent by traditional methods. In this work, we take corn cob core as instance to fabricate N‐doped hard carbon with high N content by a newly developed pyrolysis‐deposition‐self‐doping (PDSD) in confined graphite canister. Compared with the traditional method of pyrolysis by placing the sample in an open corundum crucible, the N doping amount of hard carbon obtained by PDSD method in a sealed graphite canister significantly increases from 0.93 to 5.63 at%. It demonstrates the crucial function of confined graphite canister in tuning the doped heteroatom's weight of carbon matrix. The influence of two kinds of pyrolysis methods on the microstructure of the materials was systematically analyzed by X‐ray diffractometer, Raman, X‐ray photoelectron spectrometer, and high resolution transmission electron microscopy (HRTEM). Furthermore, corresponding electrochemical tests are measured as anode materials for sodium‐ion batteries and the results suggest that the product prepared by PDSD method exhibits better cycling and rate performance. This fully proves the advantages of PDSD method for improving the amount of heteroatom doping, and lays the experimental and theoretical foundation for the future research and development of heteroatom doped carbon materials. [ABSTRACT FROM AUTHOR]

Mesoporous Fe/C and core–shell Fe–Fe 3 C@C composites were successfully prepared through the in-situ polymerization of Fe 3+ /phenolic resin coupled with F127 and the subsequent high-temperature carbonization. The experiments involved the preparation of an iron-containing carbon precursor and the heat-treatment process. Two composites with different morphology and structure could be obtained by changing the content of Fe(NO 3 ) 3 ·9H 2 O in the precursor. The crystalline phase, structure and microwave absorption of the two composites were investigated. Fe particles were uniformly embedded into the mesoporous networks to form mesoporous Fe/C composite with high surface area of 467.3 m 2 /g and low density of 1.92 g/cm 3 . The Fe–Fe 3 C particles encapsulated by graphitized carbon layers formed the core–shell structure with surface area and density of 259.5 m 2 /g and 2.67 g/cm 3 . Fe/C and Fe–Fe 3 C@C composites exhibited excellent electromagnetic absorbing ability, the effective absorption bandwidth reached 3.36 and 5.04 GHz with the matching thicknesses of 2 and 1.5 mm correspondingly. This originated mainly from the effective impedance match and multiple interfacial polarizations. Furthermore, the increase of Fe 3+ not only promoted the graphitization degree of carbon shell, but also increased the complex permittivity and permeability of core–shell structure, thus improved the impedance matching. Owing to high surface area, low density and excellent microwave absorbability, the mesoporous Fe/C and core–shell Fe–Fe 3 C@C composites are promising candidates as lightweight and high-efficiency microwave absorbents. [ABSTRACT FROM AUTHOR]

Coronavirus Disease 2019 (COVID-19) is a grave and pervasive global infectious malady brought about by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2), posing a significant menace to human well-being. Qingfei Paidu decoction (QFPD) represents a pioneering formulation derived from four classical Chinese medicine prescriptions. Substantiated evidence attests to its efficacy in alleviating clinical manifestations, mitigating the incidence of severe and critical conditions, and reducing mortality rates among COVID-19 patients. This study aims to investigate the protection effects of QFPD in mice afflicted with a coronavirus infection, with a particular focus on determining whether its mechanism involves the NLRP3 signaling pathway. The coronavirus mice model was established through intranasal infection of Kunming mice with Hepatic Mouse Virus A59 (MHV-A59). In the dose-effect experiment, normal saline, ribavirin (80 mg/kg), or QFPD (5, 10, 20 g/kg) were administered to the mice 2 h following MHV-A59 infection. In the time-effect experiment, normal saline or QFPD (20 g/kg) was administered to mice 2 h post MHV-A59 infection. Following the assessment of mouse body weights, food consumption, and water intake, intragastric administration was conducted once daily at consistent intervals over a span of 5 days. The impact of QFPD on pathological alterations in the livers and lungs of MHV-A59-infected mice was evaluated through H&E staining. The viral loads of MHV-A59 in both the liver and lung were determined using qPCR. The expression levels of genes and proteins related to the NLRP3 pathway in the liver and lung were assessed through qPCR, Western Blot analysis, and immunofluorescence. The administration of QFPD was shown to ameliorate the reduced weight gain, decline in food consumption, and diminished water intake, all of which were repercussions of MHV-A59 infection in mice. QFPD treatment exhibited notable efficacy in safeguarding tissue integrity. The extent of hepatic and pulmonary injury, when coupled with QFPD treatment, demonstrated not only a reduction with higher treatment dosages but also a decline with prolonged treatment duration. In the dose-effect experiment, there was a notable, dose-dependent reduction in the viral loads, as well as the expression levels of IL-1β, NLRP3, ASC, Caspase 1, Caspase-1 p20, GSDMD, GSDMD-N, and NF-κB within the liver of the QFPD-treated groups. Additionally, in the time-effects experiments, the viral loads and the expression levels of genes and proteins linked to the NLRP3 pathway were consistently lower in the QFPD-treated groups compared with the model control groups, particularly during the periods when their expressions reached their zenith in the model group. Notably, IL-18 showed only a modest elevation relative to the blank control group following QFPD treatment. To sum up, our current study demonstrated that QFPD treatment has the capacity to alleviate infection-related symptoms, mitigate tissue damage in infected organs, and suppress viral replication in coronavirus-infected mice. The protective attributes of QFPD in coronavirus-infected mice are plausibly associated with its modulation of the NLRP3 signaling pathway. We further infer that QFPD holds substantial promise in the context of coronavirus infection therapy. [Display omitted] • Qingfei Paidu decoction protects the coronavirus infectious mice, cosisted of Chinese herbs. • It improves the infectious symptoms and the lung and liver tissue injury. • It inhibits the replication of coronavirus MHV-A59 in mice. • The protective effect of it may be due to inhibition of the NLRP3 pathway. [ABSTRACT FROM AUTHOR]

A facile one-pot microwave-assisted hydrothermal synthesis of rutile TiO2 quadrangular prisms with dominant {110} facets, anatase TiO2 nanorods and square nanoprisms with co-exposed {101}/[111] facets, anatase TiO2 nanorhombuses with co-exposed {101}/{010} facets, and anatase TiO2 nanospindles with dominant {010} facets were reported through the use of exfoliated porous metatitanic acid nanosheets as a precursor. The nanostructures and the formation reaction mechanism of the obtained rutile and anatase TiO2 nanocrystals from the delaminated nanosheets were investigated. The transformation from the exfoliated metatitanic nanosheets with distorted hexagonal cavities to TiO2 nanocrystals involved a dissolution reaction of the nanosheets, nucleation of the primary [TiO6]8− monomers, and the growth of rutile-type and anatase-type TiO2 nuclei during the microwave-assisted hydrothermal reaction. In addition, the photocatalytic activities of the as-prepared anatase nanocrystals were evaluated through the photocatalytic degradation of typical carcinogenic and mutagenic methyl orange (MO) under UV-light irradiation at a normal temperature and pressure. Furthermore, the dye-sensitized solar cell (DSSC) performance of the synthesized anatase TiO2 nanocrystals with various morphologies and crystal facets was also characterized. The {101}/[111]-faceted pH2.5-T175 nanocrystal showed the highest photocatalytic and photovoltaic performance compared to the other TiO2 samples, which could be attributed mainly to its minimum particle size and maximum specific surface area. [ABSTRACT FROM AUTHOR]

Abstract: Rod‐like, rhombic, octahedral bipyramid‐shaped, cuboid, and spindle‐like anatase TiO2 nanocrystals samples with part of {101}, {001} and {010} facets exposure were synthesized through a straightforward solvothermal treatment of layered tetratitanate nanobelt colloidal solution precursor. The shape and structural evolutionmechanism of the as‐synthesized anatase TiO2 nanocrystals from the layered tetratitanate nanobelts were investigated by using X‐ray diffraction (XRD), field emission scanning electron microscopy (FESEM), and transmission electron microscope (TEM) and high‐resolution transmission electron microscope (HRTEM). The transformation from the layered tetratitanate nanobelts into the various morphologies anatase TiO2 nanocrystals may experience two stages during the solvothermal process including an in situ topotactic dehydration reaction of the layered tetratitanate nanobelts, and a dissolution‐recrystallization reaction of the nanobelts anatase TiO2 crystals along the different planes. Furthermore, the photocatalytic activity of the various morphologies anatase TiO2 nanocrystals was also investigated and discussed, and compared to the benchmark P25 TiO2 nanocrystals. The results revealed that the {010}‐faceted spindle‐like anatase TiO2 nanocrystals exhibited the most superior photocatalytic activity for the degradation of methylene blue. [ABSTRACT FROM AUTHOR]

• Non-metal doping Ni@C catalysts were applied in HDS of DBT. • The HDS activity was as the following sequence, Ni 2 P@C > Ni@C ≈ Ni 2 Si@C > NiS 2 @C. • The highest DBT consumption rate of 191.7 nmol·g−1·s−1 was achieved over Ni 2 P@C at 340 °C. • Ni 2 P@C catalyst showed outstanding stability over an 80 h DBT HDS. The development of highly efficient non-sulfide hydrodesulfurization (HDS) catalyst is still an extremely urgent and challenging matter for the ultra-deep HDS of crude oils. Based on the strategy of non-metal doping and incorporation of carbon, Ni 2 P@C, Ni 2 Si@C, and NiS 2 @C catalysts are successfully prepared through temperature-programmed route using MOF-derived Ni@C as precursor and investigated on the HDS of dibenzothiophene. The Ni 2 P@C sample has the highest HDS performance and the rate constant is 3.890 min−1, which corresponds to a 6-fold enhancement of that over Ni@C catalyst. While the Ni 2 Si@C catalyst corresponds to a 1.3-fold enhancement of that over Ni@C catalyst. The predictable result for the NiS 2 @C catalyst is very low HDS activity. There is a charge transfer between Ni and P or Si, which promotes the adsorption and reaction of dibenzothiophene. Moreover, the Ni 2 P@C catalyst shows outstanding stability during the long-term reaction after an 80 h. These results indicate that the non-metal doping and incorporation of carbon may be a powerful approach to improve the catalytic activity and improve the durability of catalyst for clean liquid fuels. [Display omitted] [ABSTRACT FROM AUTHOR]