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Transition oxides are a kind of promising anode materials for lithium-ion batteries due to their high capacity and low cost. However, it is a great challenge to realize high power density and long cycle life. Size control and surface coating are effective ways to increase reaction sites and improve electrical conductivity. In this work, rice crust-like structure of thin carbon layer coated Fe3O4 nanoparticles (∼15 nm) uniformly covering rGO sheets (Fe3O4@C/rGO) is achieved. This composite delivers a high capacity of 594 mAh g−1 even after 1000 cycles at a high current rate of 5.0 A g−1, which can be attributed to the high surface pseudocapacitance dominated storage mechanism. Further analysis reveals that the high extrinsic pseudocapacitance is closed to the nanosized structure and carbon coating, because large surface area and good electrical conductivity are essential for the improvement of extrinsic pseudocapacitance. This work offers a new perspective for future structure design for high-rate and long-life anode materials of lithium-ion batteries.

In this article, nitrogen is successfully doped into both components of TiO2/reduced graphene oxide composites via a hydrothermal-post thermal treatment. The N-doped TiO2/reduced graphene oxide electrode presents obviously higher Li-ion storage performance (270 mAh g−1 at current density of 0.1 A g−1) than the undoped product. This N-doped composite could also exhibit superior long-term cycling stability with a reversible capacity of 210 mAh g−1 even after 2000 cycles. Further electrochemical analysis finds the number of active Li-ions is increased from the formation of N Ti O and N C bonds, which greatly improves the charge/discharge process in the anode for lithium-ion batteries. This work may improve understanding of the doping effects of various elements present in electrode materials.

The binding configurations of the nitrogen have a great influence on the performance of the doped graphene-based lithium ion batteries anode, while the mechanism of lithium storage is still unclear. In this paper, the binding configuration of the nitrogen is controlled in doped graphene by introducing little sulfur atoms to produce more proportion of graphite nitrogen, which have an excellent cyclic performance with delivering 589 mAh g−1 at 5 A g−1 after 1000 cycles in the lithium ion batteries anode. What's more, the kinetics is improving with higher lithium ion diffusion coefficient and a smaller impedance of charge-transfer compared to the samples which do not regulated the binding configurations of the nitrogen. The characteristic electronic structure of graphite nitrogen is considered to reveal the lithium storage mechanism. Consequently, this work can provide a new insight for regulating binding configurations of nitrogen to improving lithium storage kinetics of the doping graphene electrodes.

Bismuth tungstate is used as a high potential photocatalytic material, which does not only degrade environmental pollutants but also produces hydrogen for energy use. However, a significant challenge is that the electrochemical potential of its conduction band is more positive, which leads to a weak reduction ability of photogenerated electrons, limiting further improvements in photocatalytic performance and commercial applications. This study proposes a strategy for improving the reduction ability of photogenerated electrons by using Ce/N as a cations/anion to partially replace the W/O position in the Bi2WO6 and to regulate the conduction band potential to move negatively. Meanwhile, N-doped energy level is introduced at the top of a valence band to narrow bandgap width and improve visible light absorption ability, as well as make the photoelectric charge move efficiently. First-principles simulation based on DFT is first used to calculate the energy band structure, density of electronic states and charge density of doped Ce/N materials. Theoretically, doped Ce/N ions can cause the conduction band potential to shift negatively and form an impurity level, which is beneficial to light absorption and electron movement. The degradation efficiency of as-prepared BWCeO-4 and BWCeNO-4 up to 95.5% and 85% was achieved within 90 min under visible light irradiation. Hydrogen production reached 16.89 mmol g−1 and 14.78 mmol g−1 after 4 h reaction time, respectively.

Sb2O5 is considered as a high capacity promising anode for LIBs and SIBs due to its high theoretical capacity of 1324 mAh·g−1. However, the large volume expansion during the cycling process makes the SEI film on its surface continuously reorganize and even break, which limits its electrochemical performance. In this work, we construct an anode consisting of Sb2O5 nanoparticles grown on carbon cloth with coating SiO2 (denoted as SiO2/Sb2O5/CC) to improve the structure of SEI film, which realizes stable SEI film and brings high energy storage performance. When SiO2/Sb2O5/CC composites are used as anode material for LIBs and SIBs, they both have high specific capacity and stable cycle performance (909.5 mAh·g−1 at 1 A·g−1 after 500 cycles) in LIBs and (630.7 mAh·g−1 at 200 mA·g−1 after 150 cycle s ) in SIBs. That is attributed to the SiO2 has a positive synergistic effect on the structure and electrochemical properties of Sb2O5 materials. Specifically, the existence of SiO2 slows down the repeated fracture and recombination of SEI film caused by the volume effect of Sb2O5. So the reversibility of electron and ion transport is better, and the capacity retention is better. Consequently, this wok can provide new insight for exploration and design of Sb2O5 anode materials for LIBs and SIBs.

The layered niobium oxide H4Nb6O17 (HNO) crystal has an open layered structure. The H2O2 molecules can enter rapidly into the interlayers of HNO crystal, and coordinate with Nb within NbO6 octahedron to form the peroxy bond intercalated HNO crystal (P-HNO). The introduction of peroxy bond causes the positive shift of the CB minimum of HNO crystal from −0.39 eV to 0.42 eV, resulting in its band gap narrowing from 3.49 eV to 2.68 eV and the improvement of visible light absorption. The photocatalytic investigation indicates that such P-HNO crystal has the visible light photocatalytic performance for RhB dye degradation. Moreover, the trapping experiment indicates that h+ and are the main active species during the visible light photocatalytic degradation of RhB dye. And the study of photocatalytic degradation mechanism shows that there is a synergy between P-HNO crystal and RhB during the photodegradation of RhB.

Elaborate design of high-performance anode materials is of vital significance for lithium-ion batteries (LIBs). Herein, carbon-coated MoO3 nanorods decorated with WO2 nanoparticles (MoO3/WO2@C), a novel structured nanohybrid in which MoO3 nanorods are encapsulated by the amorphous carbon layer and decorated with ultrasmall WO2 nanoparticles, have been successfully synthesized via a facile one-step hydrothermal method. When evaluated as the anode materials for LIBs, the effects of different carbon contents in the as-obtained MoO3/WO2@C nanomaterials on the lithium-ion storage properties are investigated. Results show that the MoO3/WO2@C nanocomposite with the optimized carbon content delivers a high reversible capacity of 815 mAh·g−1 after 100 cycles at 0.05 C and an ultrastable capacity of 80 mAh·g−1 at least 5000 cycles at the current density of 1 C.

The CoTiO3 decorated rGO sheet nanocomposites have been prepared by a facile sol-gel method. The obtained rGO/CoTiO3 nanocomposites exhibited enhanced sensitivity to ethanol vapor at relatively low working temperature. The relationship between microstructure and sensing properties of rGO/CoTiO3 was investigated to clarify the sensing mechanism. The results showed that the rGO concentration of the composite influenced the sensing performance significantly. The S4 sample with 3.9 wt% GO is the most sensitive and selective to ethanol gas at optimal working temperature of 195 °C. The response of S4 to 10 ppm ethanol is 5.5 and the response/recovery time is 2 s/4 s. Compared to pure CoTiO3, the operating temperature decreased 150 °C. The enhanced sensitivity is mainly attributed to following aspects. (1) High conductivity at relatively low temperature due to the presence of rGO; (2) The rGO/CoTiO3 p-p nanojunctions facilitate additional chemisorption of oxygen and carrier transfer; (3) More Ti3+ concentration in the crystal lattice which offers more active adsorption sites. Besides, Ti3+ is an effective catalyst for redox reaction between ethanol and the adsorbed oxygen. (4) The rGO nanosheets which contain functional groups (C O and COOH) may catalyze the gas adsorption, desorption process and activate the subsequent gas redox reaction.

The low diffusion rate of pure TiO 2 affects the inferior electrochemical performance such as cycling capacity and rate capability. Many works have been focusing on the material structural control to solve this problem, but the specific mechanism of the electrochemical process still needs further study. In this paper, we prepare titanium dioxide/reduced graphene oxide (TiO 2 /rGO) hybrids to comprehend the improved diffusion rate by using electrochemical kinetics characterization. Compared with pure TiO 2 , the TiO 2 /rGO hybrids have a reduced particle size and layer-shaped structure. For electrochemical test, the TiO 2 /rGO assembly exhibits high rate capability (∼270 mAh g −1 at 0.1 A g −1 ), and excellent cycling capacity (∼180 mAh g −1 at 0.5 A g −1 after 2000 cycle). Studying the electrochemical reaction process finds that the charge transfer rate of titanium oxide were significantly increased due to the addition of graphene oxide. A diffusion controlled behavior of Li + is found to dominate the charge-discharge process in TiO 2 /rGO hybrids, rather than the capacitive process of the pure TiO 2 electrode. This dominated diffusion is believed to inspire both of superior rate and capacity of the TiO 2 /rGO hybrids in this work.

In present work, the three-dimensional (3D) sphere-like SnS 2 and network-like SnS 2 (the obtained samples respectively denoted as SnS 2 -SP and SnS 2 -NW) are successfully fabricated using a facile one-step process performed at low reaction temperature for a reduced time. It is found that the structure of the SnS 2 -NW prepared in a water-bath environment for 75 min is composed of self-assembled nanoflakes, the thickness of the cross-linked flakes is in a range of 5–10 nm. The layer spacing along the c-axis and specific surface area of SnS 2 -NW sample are larger than that of the SnS 2 -SP. When SnS 2 -SP and SnS 2 -NW materials are applied as anode electrodes of lithium-ion batteries (LIBs), the network-like SnS 2 electrode exhibited high reversible capacity of 401.31 mA h g −1 after 100 cycles at 100 mA g −1 , with a capacity loss of 0.5% per cycle. The SnS 2 -NW electrode can still retain a discharge capacity of 358.71 mA h g −1 with almost 99.7% coulombic efficiency even at 800 mA g −1 , demonstrating excellent rate capacity and cycling performance, which are superior to that of the SnS 2 -SP electrode. The results demonstrate significant potential of SnS 2 -NW for application as anode of the LIBs.

Cu2V2O7/reduced Graphene Oxide (CVO/rGO) mesoporous microspheres were prepared by low temperature hydrothermal method and the following heat treatment process. The structures and morphology were characterized by X-ray diffraction (XRD), field-emissing scanning electron microscopy (FE-SEM). The reversible capacities of this mesoporous microspheres is 830 mAh·g−1 at 0.1 A g−1 after 200 cycles without capacity fade, which also exhibit superior rate capabilities with reversible capacities of 524 and 170 mAh·g−1 after 10 cycles at 1 and 5 A g−1, respectively. These excellent electrochemical properties may be attributed to the unique structures and the synergistic energy storage effect of rGO nanosheet and Cu2V2O7.

The controlled conversion of biomass is necessary for their efficient utilization. In this work, we report the controlled synthesis of a novel macroscopic three-dimensional hollow reticulate hard carbon by hydrothermal pretreatment and further low temperature (600 °C) pyrolysis method. The carbonization mechanism is presented based on differential thermal analysis, which shows that the hydrothermal pretreatment gets through the reticulate structure by removing flavonoids and the pyrolysis temperature is a key factor for inheriting the unique architecture. Tested against sodium, the hard carbon exhibits good cycling stability, showing capacity retention of 90% after 1000 cycles. The excellent Na-ion storage property is attributed to the interconnected three-dimensional architecture, the abundant O-containing functional groups and the large interlayer spacing.

The development of efficient photocatalysts is of paramount significance for sustainable availability of solar energy. Herein, hollow α-Ag 3 VO 4 photocatalysis crystallites were successfully synthesized via a facile one-pot hydrothermal approach without modifier. The morphology, phase composition and crystal structure of α-Ag 3 VO 4 crystallites are strongly dependent on the pH values of the precursor solution, and the formation of hollow α-Ag 3 VO 4 nanospheres merely occurs at pH = 10. Furthermore, hollow α-Ag 3 VO 4 nanospheres exhibit superior photocatalytic activities compared with bulk α-Ag 3 VO 4 for the degradation of Rhodamine B (Rh B) under the simulated solar light, achieving up to 97% degradation in 2 h irradiation. This improved photocatalytic performance of hollow α-Ag 3 VO 4 nanospheres is primarily attributed to the synergistic effect of the improved electron-transfer efficiency, the extended light absorption range and effective separation of electron-hole pairs.

Whisker reinforcement can enhance the thermal shock resistance of coating. Here, a mullite whisker-toughened silicate glass coating for SiC pre-coated carbon/carbon composites (SiC-C/C) was prepared by a molten salt and hot dipping method. The microstructure, interface bonding strength and thermal shock resistance of the coating were investigated. Results show that preparing the buffer mullite whisker layer and incorporating the mullite whisker can effectively improve the coating interface bonding and decrease the size of microcracks. The as-prepared coating has an enhanced thermal shock resistance and the weight loss of the coated samples was only 2.21% after 100 thermal cycles.

The effects of hydrothermal penetration temperature on the ablation properties of C f /C-SiC-MoSi 2 composites were studied. With the hydrothermal temperature rising, the distribution depth of ceramics along the cross-section of the composites increased. Meanwhile, the increase in densities and the decrease in porosities of the composites were achieved. When the penetration temperature reached 200 °C, the composites showed the best ablation properties after plasma ablation test for 60 s at 2300 °C. The mass ablation rate was 2.28 mg cm −2 s −1 , which decreased by 65%, 54% and 29% compared to composites prepared at 140 °C, 160 °C and 180 °C, respectively. Also the sample prepared at 200 °C showed the lowest linear ablation rate. The increasing depth and amount of ceramics in the composites could provided SiC and MoSi 2 continuously to prevent the oxidation of carbon, rather than be easily blown away by strong scouring force. The good ablation behavior is attributed to the higher density and amounts of ceramics, the generation of SiO 2 and MoO 2 .

The single phase β-Y 2 Si 2 O 7 nanowires were synthesized via a facile molten salt method. The phase composition, microstructure, formation mechanism and the phase transformation of the β-Y 2 Si 2 O 7 nanowires were investigated, as well as the thermal properties of the corresponding β-Y 2 Si 2 O 7 ceramic. Results show that the molten salt method can effectively decrease the synthesis temperature. Furthermore, the molten salt temperature has a crucial influence on the crystal phase composition and the crystal morphology. The obtained β-Y 2 Si 2 O 7 nanowires possess low thermal conductivity (1.84 W m −1 K −1 ) and low thermal expansion coefficient (3.88 × 10 −6 K −1 ), which make them a promising candidate toughening material on coatings.

Binders play a significant role in enhancing the electrochemical performance of tin disulfide (SnS2) as the anode for lithium-ion batteries (LIBs) because of their excellent dispersion and cohesion in the electrodes. In the present work, flake-like SnS2 nanoparticles with a hexagonal structure were synthesized by a facile one-step hydrothermal method with a mean grain size of 7.7 nm. When sodium alginate (SA), carboxymethyl cellulose (CMC), poly acrylic acid (PAA), and CMC-PAA (1:1, wt%) are applied as binders for the SnS2 anode electrode (the obtained electrodes are denoted as SnS2-S, SnS2-C, SnS2-CP, and SnS2-P, respectively) in LIBs, the electrodes exhibited high reversible lithium-ion storage capacities of 762.00 mA h g−1, 891.65 mA h g−1, 913.94 mA h g−1, and 930.36 mA h g−1 at the current densities of 100 mA g−1, respectively. Importantly, the SnS2-P electrode exhibited excellent rate capacity and cycling performance. The –COOH of PAA attached to SnS2 can increase the amount of free radicals, which can prevent the detachment of SnS2 from the current collector, and the carboxyl group can effectively inhibit the volume expansion and pulverization of particles of the electrode. Undoubtedly, PAA binder significantly improves the cycling and rate performances of SnS2 anode material for LIBs.

Different crystal nanostructural WS2 sheets play a significant role in the improvement of their electrochemical performances as anode for sodium ion batteries (SIBs). Here we investigate that WS2 nanosheets with diverse crystal planes are fabricated by a simple two-step method. Especially, (002)-oriented WS2 nanosheets with broad interlayer spacing are achieved by a facile controlling the sulfurized time (1 h, 2 h and 3 h). This (002)-oriented crystal structure for WS2 electrode can deliver the better cyclic stability (85% capacity retention after 100 cycles at 100 mA g−1) and the higher rate performance (capacity of 148 mA h g−1 at the current density of 2000 mA g−1) than other (100)-oriented WS2 nanosheets. Further investigations indicate that (002)-oriented WS2 nanosheets with high crystallinity possess stable structure, which can provide effective channels for accommodating more Na+ and accelerate the ionic/electron transportation. This method reveals that the structural design and fabrication of different crystal orientation can be considered as potential ways to improving the electrochemical performances of WS2 anode, as well as that of other anodes in SIBs.

Hard carbon with large interlayer spacing is suitable as the anode material for sodium-ion batteries. Rape seed shuck derived lamellar hard carbon is synthesized through hydrothermal and pyrolysis processes. As the anode, it exhibited good cycling stability, delivering a capacity of 143 mAh g −1 after 200 cycles at 100 mA g −1 . The promising performances are attributed to the sheet structure with expanded interlayer distance (0.39 nm) and much void which can lower the sodium-ion insertion-extraction barrier and promote Na-ion diffusion and storage. The effect of pyrolysis temperature on the performance is also investigated.

Self-assembly flower-like WO3/W18O49 and W18O49 were synthesized through a facile solvothermal method. By reducing the content of oxygen, the phase of WO3/W18O49 changes to pure W18O49 and the morphology of the W18O49 shows an obvious evolution from nanowire to flower-like W18O49 assembled by nanoneedle. The crystallite size of WO3/W18O49 and W18O49 are 29.85 nm and 14.13 nm, respectively. The photocatalytic activity of W18O49 UV-light irradiation is about 8 times as high as that of WO3/W18O49. This enhanced activity is attributed to smaller crystallite size and larger surface area. Furthermore, XPS analyses reveal that the lattice oxygen reduces under N2 atmosphere. The increasing of oxygen vacancy results in a narrowing bandgap and strong light absorption performance. By combining the results of the transient photocurrent and electrochemical impedance measurements, the electron-hole pair separation rates and carrier migration rates of the W18O49 have been greatly improved.

Development of highly active, durable electrocatalysts involving cheap and earth-abundant non-precious metals for the electrocatalytic hydrogen evolution reaction (HER) is of great significance for green hydrogen fuel production. Herein, we report a novel ultrafine VN nanoparticle (2–4 nm) dispersedly confined in Co-encapsulated N-doped carbon nanotubes (VN/Co@NCNT) by a facile one-pot NH3-free pyrolysis method. When applied for the electrocatalytic HER, the as-obtained VN/Co@NCNT material exhibits greatly improved catalytic activity compared to bulk VN and Co@NCNT counterparts, with a quite low overpotential of 180 mV at 10 mA cm−2 (VN: 342 mV; Co@NCNT: 313 mV), accompanying a remarkable catalytic durability for over 60 h and approximately 100% Faradaic efficiency in alkaline media. The enhanced electrocatalytic HER performance of VN/Co@NCNT can be mainly attributed to the exposed high-density catalytically active sites of ultrafine VN nanoparticles, the fast mass and electron transport over Co-embedded graphitic carbon nanotubes, as well as the enhanced electrical conductivity by the graphitic and pyridinic N-doping effects.

Assembled-sheets-like MoO3 (A-MoO3) has been synthesized from precursor hexagonal-rods (H-MoO3) with a facile heat treatment route. The assembled sheets structure is much looser than H-MoO3. As an anode for lithium ion batteries, A-MoO3 maintains an improved discharge capacity of 889 mAh g−1 over 100 cycles with capacity retention of ∼100%, compared with H-MoO3. Meanwhile, A-MoO3 delivers enhanced rate capability (567 mAh g−1 at 2 C). The excellent cycle stability and better rate performance of A-MoO3 are associated with a porous-interweaved structure obtained after several cycles. The porous-interweaved structure can facilitate lithium ion and electron transfer. Over 100 cycles, the stable structure can be still preserved, exhibiting better structural stability than precursor H-MoO3. The enhanced electrochemical performance makes the A-MoO3 a promise for applications as high capacity lithium ion batteries anodes.

The soft chemical process is a useful and unique method for the preparation and design of mesocrystals materials. The platelike Ag 2 Nb 4 O 11 mesocrystals are prepared via the soft chemical topotactic reaction using the layered structure K 4 Nb 6 O 17 platelike particles as precursor. The formation mechanism is investigated through tracing the evolution of structure and morphology of intermediate products during the reaction, and it contains two processes. One is the ion-exchange reaction with the interlaminar ions of layered precursor. The other is in situ topotactic structure transformation reaction of the platelike Ag 3 HNb 6 O 17 into platelike Ag 2 Nb 4 O 11 mesocrystals during the heat-treatment process. Moreover, the degradation of RhB over the platelike Ag 2 Nb 4 O 11 mesocrystals can reach to 95.3% after the irradiation of 20 min. The enhancement of photocatalytic performance of Ag 2 Nb 4 O 11 mesocrystals can be attributed to its unique morphology and exposed facet, which affect the band gap and energy band structure.

WS2-Super P nanocomposites are prepared for lithium battery anodes by a simple two-step process consisting of hydrothermal and sulfide reduction reactions. The addition of Super P (50 nm) as a conductive addictive is beneficial for decreasing the size of nanocomposites and improving their dispersibility, which could accelerate the insertion/extraction reaction between WS2-Super P nanocomposite electrode and electrolyte. Compared to the pure WS2, the WS2-Super P nanocomposites exhibit highly improved electrochemical performance with initial discharge capacity of 421 mAh g−1, high initial Coulombic efficiency (81%), low charge transfer impedance (53 Ω) and good retentive capacity of 389 mAh g−1 after 200th cycles. The much improved electrochemical performance can be attributed to the incorporation of Super P, which facilitates the interface charge transfer and Li+ diffusion.

Well crystallized cubic sphalerite phase ZnS micro/nanocrystallites with controllable morphologies were successfully prepared by a facile and efficient microwave hydrothermal method. The syntheses were carried out by varying the Zn/S molar ratios. The phase compositions, morphologies and optical properties of the as-prepared samples were characterized by X-ray diffraction, scanning electron microscopy and UV–vis diffuse reflectance spectroscopy. Results show that with Zn/S molar ratio ranges from 2:1 to 1:2, the morphology of the prepared ZnS micro/nanocrystallites changed obviously. ZnS nanoparticles with good dispersibility prepared at Zn/S molar ratio of 1:2, which average size is about 20 nm, shows high photocatalytic activity to degrade Methyl orange (MO). The degradation efficiency of ZnS nanoparticles reaches 97.4% under UV irradiation for 20 min. The good ultraviolet absorbing ability and big specific surface area of ZnS nanoparticles are believed to have a positive impact on improving the final degradation rate and degradation efficiency of MO in our research.

Super P was firstly used to enhance the electrochemical performance of SnO2 as anode in Na-ion battery. This composite was prepared by a simple hydrothermal method, exhibiting uniformly dispersed SnO2 nanoparticles on the super P carbon spheres. The SnO2/C nanocomposite could deliver a discharge capacity of 293 mAh g−1 after 100 cycles at a current density of 50 mA g−1. Even at 1000 mA g−1, a capacity of 150 mAh g−1 was still maintained. Further study found that SnO2/super P nanocomposite provided a high Na ion diffusion coefficient and good structural stability during the cycling test. Combining the advantages of low cost and environmental benignity suggest the SnO2/super P composites in this work have great potential as a promising anode for high performance Na-ion battery.

Stress is an important characteristic that affects the properties of materials. However, few reports on how stress affects sodium storage behavior. In this article, we manipulate the stress of Sn in carbon structure to inhibit the volume expansion of Sn. As an anode for SIBs, carbon-coated Sn@SnO2/CC exhibits a capacity of around 400 mAh/g at 1 A/g after 800 cycles. After further research, it is found that the existence of compressive stress can significantly improve the charge and discharge stability of the material. Meanwhile, it can stabilize the structure and morphology of material and maintain the stable charge transfer process between Sn and carbon structure. These results reveal the effect of stress on the behavior of sodium storage. It provides reference to the practical application of other materials with alloy reaction mechanism as high performance sodium ion battery anode material.

Hierarchical porous carbons embedded with graphitic domains were synthesized by carbonization of seaweeds with a catalytic graphitization strategy. The Ni2+ ions are pre-chelated with seaweeds precursor (porphyra) to enable a catalyst confined graphitization process and to provide mesopores template. Carbonization temperature is significant in tailoring graphitic degree and porosity structure of porphyra-derived carbons (PDCs). The PDCs carbonized at 900 °C (PDC-900) show favorable features for electrochemical energy storage, which balance the specific surface area (515.7 mm2g-1), degree of graphitization (ID/IG = 0.78), expand graphite interlayer spacing (∼0.342 nm), and N-doping (2.13 wt%). These unique features of PDC-900 not only can supply abundant sites for the storage and insertion of Li ions, but also can facilitate rapid mass transport of electrons and Li ions. Thus, PDC-900 shows remarkable reversible capacity (950 mAhg−1 at 0.1 C), excellent rate capability (352 mAhg−1 at 10 Ag-1), and superior cycling performance (348 mAhg−1 at 5 Ag-1 after 3000 cycles), when used as an anode material for lithium ion batteries.

Crystal facets-orientation growth plays a crucial role in determining photocatalytic performance. Herein, a series of (010) facets-oriented W18O49 nanowires were controllably synthesized by a facile solvothermal alcoholysis method using octadecylamine as the crystal growth capping agent in order to regulate the specific growth behavior and unveil its correlation with photocatalytic performance. The properties of the prepared W18O49 nanowires, such as surface oxygen vacancies, light absorption and the band gap size, as well as the surface charge carriers separation rate, could be well-modulated via tailoring the preferred orientation growth. The W18O49 nanowire with the strongest (010)-faceted orientation demonstrated the best photocatalytic degradation of Methyl Orange under ultraviolet light irradiation (up to 100% within 15 min) and visible light irradiation (up to 91% within 95 min). These interesting findings not only help us to gain an in-depth understanding of the relationship between the preferred orientation growth and the photocatalytic performance but also have the potential to open up an innovative route/protocols for the preparation of crystal facets-oriented metal oxides for highly efficient photocatalysis.

Hard carbon becomes a candidate for anode materials due to its rich resources and abundant lithium storage sites. However, amorphous carbon with poor stability and electronic conductivity limits its electrochemical performance. In response, this work synthesizes a sandwich-like porous hard carbon/graphene hybrid (HC/G) with graphene sandwiching the hard carbon via a KOH-assisted one-step pyrolysis process from rapeseed shuck. The highly ordered graphene layers constitute conductive multi-dimensional paths for fast electronic transport and supply sufficient electrons for redox reactions. Moreover, the sandwiching graphene layers provide mechanical support, which effectively adapts volume change to stabilize the whole structure. The porous hard carbon with numerous defects and C O groups could provide more adsorption sites and redox reactions for lithium storage. When serving as anode material, HC/G displays a stable lithium storage capacity of 623 mAhg−1 at a current density of 100 mAg−1 after 500 cycles, and exhibits a superior rate performance that of 381 and 308 mAhg−1 even at a higher rate of 2000 and 5000 mAg−1, respectively. This work sheds a light on the high-value use of waste rapeseed shuck for eco-friendly and low cost lithium-ion batteries anode material.

Constructing polycrystalline structure is an effective strategy to improve the electrochemical performance of electrode materials. To enhance the electroactivity of anisotropic VO2(M), polycrystalline VO2(M) with well-dispersed crystalline zones is successfully synthesized by a facile one-step hydrothermal method, and then their electrochemical performances as an anode of lithium-ion batteries are systematically explored. Results show that the synergistic effect of crystalline zones and amorphous matrices in polycrystalline structure can dramatically activate the anisotropic VO2(M) electrode, which contributes to increasing the electroactive zones and facilitating the charge transfer kinetics. Compared with single-crystal VO2(M), polycrystalline VO2(M) shows the significantly enhanced electrochemical performance, delivering a high reversible capacity of 476 mAhg−1 at 100 mAg−1 after 150 cycles, which is far superior to the theoretical capacity and the reported mixture of VO2(M) and VO2(B). This work opens up new insights for the activation of anisotropic electrode materials.

As an indispensable part of lithium-ion batteries (LIBs), the quality of solid-electrolyte interphase (SEI) influences directly the electrochemical performance. α-FeOOH with superior theoretical capacities, low cost, and environmental friendliness has been regarded as a promising anode of LIBs. In this work, we found that the hydroxyl groups on the surface of α-FeOOH bond with organic electrolytes that forming an inferior SEI layer contained excessive ROCO2Li, finally causing a poor Li+ transport. Thus, we construct a novel heterostructure of spindle-like α-FeOOH nanorods embedded in mulberry-like Fe2O3 sphere on reduced graphene oxide sheets (F@F/C) based on the dissolution-recrystallization mechanism to optimize the composition of SEI layers. The content of ROCO2Li is decreased as expected in the SEI of F@F/C electrode, which diminish the ionic transfer impedance in the interface and provide more alternative diffusion pathways. As expected, the heterostructural hybrid achieves an excellent electrode performance with a reversible capacity about 1800 mAh g−1 at 0.2 A g−1 after 300 cycles. Even cycled at a high current density of 1 A g−1, the hybrid also remains 1050 mAh g−1 after 600 cycles with a capacity decay rate of only 0.005% per cycle.

Owing to the high theoretical capacity, Sb2Se3 has been regarded as one of the best choices for Sodium-ion batteries (SIBs) anode materials. However, Sb2Se3 anode suffers from huge volume change with poor electrode structure stability, resulting in limited cycling and rate performance. Herein, inspired by the formation of inclusion complex an effective strategy for improving unstable molecules in biological fields, we encapsulate Sb2Se3 in capsular carbon shell via a hydrothermal and calcinations process. Furthermore, by adjusting the thickness of the capsule carbon shell, an ultra-stable Sb2Se3 electrode structure is realized. Equipped with this ultra-stable electrode structure, Sb2Se3 anode exhibits high capacity of 475 mA h g−1 at 2 A g−1 even after 600 cycles, showing compelling advantage on Na storage performance compared to other reported Sb-based anode materials. The analysis results indicate that the intact capsular carbon shell can effectively remit huge volume change of Sb2Se3, and act like a reaction vessel in which the sodiation/desodiation reaction of Sb2Se3 is carried out regularly. Therefore, this ultra-stable electrode provides stable redox reactions, easy charge transfer and fast sodium ion diffusion, resulting in excellent Na storage performance of Sb2Se3 anode.

Based on the available thermodynamic parameters and experimental data of self-diffusivity, impurity diffusivity, intrinsic diffusivity, tracer diffusivity and interdiffusivity in the Cu–Si, Al–Si and Al–Cu–Si alloys, the atomic mobilities of Cu, Al and Si in face-centered cubic (fcc_A1) Cu–Si, Al–Si and Al–Cu–Si alloys have been critically assessed as a function of temperature and composition using the CALPHAD-type and DICTRA software package. Comparisons between the calculated and measured coefficients reveal that most of the diffusivities can be reproduced satisfactorily. The obtained mobility parameters can be used to study diffusion-related characteristics for fcc_A1 Cu–Si, Al–Si and Al–Cu–Si alloys.

0.94(Na0.5Bi0.5)TiO3–0.06BaTiO3 thin film was fabricated by metal–organic decomposition, and the butterfly-shaped piezoelectric response curve was measured by a scanning probe microscopy system. The remanent polarization 2Pr and coercive field Ec are 24 μC/cm2 and 103 kV/cm under 782 kV/cm, and the dielectric constant and dielectric loss are 504 and 0.05 at 1 kHz. The average values of effective piezoelectric coefficient d 33 * and electrically induced strain are 94 pm/V and 0.3% under the bipolar driving field of 391 kV/cm, and the mechanisms concerning the dependence of the high piezoelectric properties were also discussed.