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The rapid recombination of photoinduced charge carriers and low selectivity are still challenges for the CO2 photoreduction. Herein, we proposed that ZIF-67-derived Co3O4 hollow polyhedrons (CoHP) were embedded into NaCl-template-assisted synthesized 3D graphitic carbon nitride (NCN), subsequently, loading Ag by photo-deposition as efficient composites (CoHP@NCN@Ag) for CO2 photoreduction. This integration simultaneously constructs two heterojunctions: p-n junction between Co3O4 and g-C3N4 and metal-semiconductor junction between Ag and g-C3N4, in which Co3O4 and Ag serve as hole (h+) trapping sites and electron (e-) sinks, respectively, achieving spatial separation of charge carriers. The donor-acceptor structure design of NCN realize a good photogenerated e--h+ separation efficiency. The mesoporous structure of hollow Co3O4 facilitate gas-diffusion efficiency, light scattering and harvesting. And the introduction of plasmonic Ag further strengthens the light-harvesting and charge migration. Benefiting from the rational design, the optimized ternary heterostructures exhibit a high CO2-CO yield (562 μmol g-1), which is about 4-fold as high as that of the NCN (151 μmol g-1). Moreover, the conjectural mechanism was systematically summarized. We hope this study provides a promising strategy for designing efficient g-C3N4 systems for the CO2 photoreduction.

The photocatalytic conversion of organic wastewater into value-added chemicals is a promising strategy to solve the environmental issue and energy crisis. Herein, Co/In2O3 nanotubes with a double-shell structure, as a highly efficient photocatalyst, are synthesized by a one-step calcination method. The Co/In2O3 heterostructure shows an outstanding photocatalytic CO2 reduction performance of 4902 μmol h-1 g-1. Notably, these Co/In2O3 photocatalysts also achieve CO2 self-generation and in situ reduction conversion in acid organic wastewater (phenol solution), in which the high CO2 (47.5 μmol h-1 g-1) and CO (0.9 μmol h-1 g-1) evolution rates are demonstrated under solar irradiation. Transient photovoltage (TPV) tests demonstrate that Co nanoparticles on Co/In2O3 double-shell heterostructure serve as the CO2 reduction sites for the effective capture and stabilization of the photogenerated electrons.

As two important members of complex hydrides, Mg(BH4)2 and NaBH4 have a high gravimetric capacity (14.9 and 10.8 ​wt%, respectively). In this study, the Mg(BH4)2 was synthesized by the ion exchange method. Afterwards, the Mg(BH4)2 and NaBH4 composites with different amounts (30, 40 and 50 ​wt%) of NdF3 were prepared by mechanical milling. Effects of the NdF3 on the microstructural evolution and hydrogen storage properties were investigated. The results show that NdF3 catalyst can significantly improve the dehydrogenation kinetics of the eutectic composites of NaBH4–Mg(BH4)2. The onset hydrogen desorption temperature of the composites is about 88.6 ​°C, which is about 110 ​°C lower than that of Mg(BH4)2 and NaBH4 composites. Mg(BH4)2–NaBH4-0.5NdF3 composites can released 5.2 ​wt% H2 at 250 ​°C within 30 ​min, and the dehydrogenation capacity is significantly higher than that of Mg(BH4)2–NaBH4 composites. The analysis of the dehydrogenation mechanism reveals that NdF3 takes participate in the reaction to generate NaMgF3 to promote the dehydrogenation reaction process of the composites.

Photocatalytic CO2 reduction into renewable fuels by sustainable and clean solar energy can be considered as an ideal option to decrease the atmospheric CO2 level and fulfill the energy requirement...

Based on the three-dimensional ordered macroporous titanium dioxide (3DOM-TiO2), a series of gold-embedded 3DOM-TiO2 (nAu@3DOM-TiO2) with controlled Au loading amount (n = 0.24, 1.2, 2.4, 4.8, 12, and 24 wt%) was successfully fabricated via in-situ pyrolysis for the first time. Compared with the surface-modified Au/3DOM-TiO2 by traditional impregnation–reduction route, this body-doped Au@3DOM-TiO2 structure exhibited smaller particle size and better dispersive property which are important for photocatalysis. Therefore, the photocatalytic activities of nAu@3DOM-TiO2 have been tested and the optimized photocatalyst of 4.8Au@3DOM-TiO2 was identified. A possible mechanism of Au@3DOM-TiO2 for the enhanced photoactivity was well discussed. The present work demonstrated a unique “gold-embedded” interface with potential advantages of highly dispersed, anti-aggregation, easy recovery, and enhanced catalytic performance, and that this approach could provide an ideal platform for the further design of noble metal-doped semiconductors.

Two-phase Ca2+-doped LaVO4:Eu3+ nanocrystals were prepared through a hydrothermal method with the help of SOD CITR and EDTA surfactants. The phase and morphology of the products were characterized by XRD and TEM, and the fluorescence performances were also recorded. The results indicated that Ca2+ ions were doped into the LaVO4:Eu3+ host lattice, impeding the aggregation of the nanocrystals and enhancing the luminescence intensity. The morphology transformation process and luminescence enhancement were systematacially investigated. The fluorescence intensity of the two selected samples could be completely quenched by Fe3+ ions without the disturbance of other ions, with the mechanism being due to the adsorption of Fe3+ ions onto the grains and a subsequent energy transfer from Eu3+ to Fe3+. Therefore, the present two Ca2+-doped LaVO4:Eu3+ samples can be applied as appropriate candidates for detecting Fe3+ ions with agility and sensitivity in aqueous solution.

A double-shell triptycene covalent polymer@CdS hollow sphere (TCP@CdS HS) composite has been successfully synthesized by in situ growing a TCP on the surface of CdS@SiO2 spheres and then removal of the SiO2 template via alkali etching. Characterization indicates that an amorphous TCP layer is coated on the thin CdS shell via an electrostatic self-assembly process, and the TCP layer thickness can be tuned by adjusting TCP loading. The photocatalytic hydrogen generation rate of the optimal TCP@CdS HS composite is up to 9480 μmol h−1 g−1 under visible-light irradiation, which is 57, 37 and 18 times higher than those of pristine CdS HS, SiO2@CdS HS and SiO2@CdS@SiO2, respectively. Besides, the TCP@CdS HS composite possesses excellent stability, which is superior to that of SiO2@CdS HS and SiO2@CdS@SiO2. An in-depth study of the electron transfer process and the photocatalytic mechanism was performed by in situ transient photovoltage experiments, which indicate that the TCP can facilitate the diffusion of hydrogen and stabilize the photoinduced electrons. This work provides an effective strategy to design novel hollow sphere heterostructures for solar energy conversion.

How to remove harmful heavy metal ions from waste batteries or lithium cells efficiently has been the focus of scholars. More and more metal oxides had been used to deal with the pollution of heavy metal caused by waste batteries in recent years. Nanostructured metal oxides have great potential because of their large comparative areas. The adsorption for these heavy metal ions can be further improved by using modified metal oxides as adsorbents. At present, iron oxide is widely used in this field. Other metal oxides have also been studied in removing these heavy metal ions. Compared to other metal oxides, the adsorbents made of iron oxide are easy to be separated from the reaction system. pH value in the solution can affect the activity of adsorption sites on metal oxides adsorbents and change the distribution of ions in solution. As a result, pH value can significantly influence the adsorption of metal oxides adsorbents for heavy metal ions from waste batteries or lithium cells.

Square-circle hybrid section (SCHS) tubes under axial loading which combine the advantage of square tubes and circular tubes are investigated. Firstly, effective finite element models of SCHS tubes...

Novel Z-scheme-based BiVO4/CdS photocatalysts with efficient charge separation were prepared by simple in situ hydrothermal method. The compact structure of the CdS nanorod and BiVO4 nanosheet has formed a Z-scheme heterojunction. The as-prepared BiVO4/CdS composites were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Raman spectroscopy, diffuse reflection spectroscopy, photoluminescence and photocurrent techniques. It was found that the BiVO4/CdS composites had the light-absorbing range and could efficiently degrade malachite green dye under visible-light irradiation. In this report, the result of the best degrading sample could achieve 92% in 30 min under visible light, respectively. BiVO4/CdS composites perform photocatalytic efficiently due to the Z-scheme. Furthermore, the Z-scheme-based BiVO4/CdS composites leaded to a major oxidation site at BiVO4, which successfully avoided photoetching of CdS during photocatalysis. Especially, the BiVO4/CdS system exhibits great photogenerated electron–hole pairs separation capabilities and high redox capabilities. This unique method of synthesizing Z-scheme-based BiVO4/CdS heterojunction has ability to reduce the cost and promote photocatalytic in visible-light range simultaneously.

A novel and porous triptycene-based microporous polymer (TMP) was synthesized through a palladium acetate-catalyzed Suzuki reaction, and then Cd0.5Zn0.5S quantum dots (CZS QDs) were homogeneously decorated onto the TMP by a facile in situ precipitation approach to fabricate a 0D/3D heterojunction for the first time. Characterizations indicate TMP with large specific surface area (809 m2 g−1) not only stabilizes CZS QDs but also provides abundant photocatalytic active sites, which can facilitate the activation and adsorption of H2O molecules. The CZS QDs@TMP heterojunction possesses remarkably improved photocatalytic hydrogen evolution activity and outstanding photostability. The optimized CZS QDs@TMP-1 heterojunction exhibits highest hydrogen-producing rate of 81.33 mmol h−1 g−1, about 16.1 times higher than that of pristine CZS. The high photocatalytic activity of CZS QDs@TMP is due to several positive factors, such as high surface area, construction of n-n type heterostructures, tiny size effect of CZS QDs and close contact between 0D CZS QDs and 3D TMP, which will synergistically promote the visible-light response, boost the interfacial charge transfer and reduce the photocorrosion of CZS.

In this study, the composite of CdS nanorods loaded with BiPO4 nanoparticles was fabricated as a novel efficient photocatalyst and exhibited strong photocatalytic degradation activities for the degradation of organic pollutants. Among the composites with different mass ratios, 1.8BiPO4/CdS showed the best catalytic activity, and the removal rates of malachite green (MG), reactive red (X-3B) and ciprofloxacin (CIP) in 80 min were 98%, 99%, and 70%, respectively. The COD removal efficiencies of MG (55%), X-3B (50%) and CIP (44%) by 1.8BiPO4/CdS composites further proved the superiority of the performance of BiPO4/CdS heterojunctions under visible light. About 90% MG, 88% X-3B and 58% CIP could be degraded after four cycles indicating the good stability of the materials. The enhanced photocatalytic properties can be attributed to the efficient charge separation as well as interfacial charge transfer from CdS to BiPO4, which is evidenced by XPS analysis and species trapping. The well dispersion of BiPO4 on CdS can preserve it from photocorrosion, which effectively enhances the photostability of degradation properties. Moreover, several recommendations and ideas are proposed for improving the utilization of solar energy and environmental restoration in the future.

A series of thickness-controlled SrTiO3 (commonly abbreviated ST) anchored on carbonized bacterial cellulose (CBC) was successfully prepared by a novel route of freeze-drying assisted crystallization/carbonization. For the first time, the cross-linked bacterial cellulose served as a carbon source as well as structure-directing scaffold for the construction of ST/CBC composites. Characterizations exhibited cracks and defects on the surface of CBC which provided ideal anchoring sites for the dispersion and crystallization of ST. Additionally, the relationship between morphology and photocatalytic activity of ST/CBC was carefully investigated by photocatalytic reduction of potassium dichromate (K2Cr2O7) and degradation of tetracycline in water. This unique biomass-derived carbon fibers provide an ideal platform for further design of perovskite based materials with enhanced catalytic performance.

Oxide dispersed strengthened (ODS) steel is an important candidate for Gen-IV reactors. Oxide embedded in Fe can help to trap irradiation defects and enhances the strength of steel. It was observed in this study that the size of oxide has a profound impact on the depinning mechanism. For smaller sizes, the oxide acts as a void; thus, letting the dislocation bypass without any shear. On the other hand, oxides larger than 2 nm generate new dislocation segments around themselves. The depinning is similar to that of Orowan mechanism and the strengthening effect is likely to be greater for larger oxides. It was found that higher shear deformation rates produce more fine-tuned stress-strain curve. Both molecular dynamics (MD) simulations and BKS (Bacon-Knocks-Scattergood) model display similar characteristics whereby establishing an inverse relation between the depinning stress and the obstacle distance. It was found that (110)oxide || (111)Fe (oriented oxide) also had similar characteristics as that of (100)oxide || (111)Fe but resulted in an increased depinning stress thereby providing greater resistance to dislocation bypass. Our simulation results concluded that critical depinning stress depends significantly on the size and orientation of the oxide. Keywords: Oxide dispersed strengthened (ODS) steel, Molecular dynamics (MD) simulation, Edge dislocation, Orowan loop, Dislocation dynamics

In this study, ZnFe2O4/CdS composites have been successfully synthesized from decorating CdS nanospheres with ZnFe2O4 nanoparticles by a facile method. With the application of detection techniques such as X-ray diffraction, Raman spectra, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy, the crystalline structures, surface morphologies, and physicochemical performances of the samples have been investigated in this study. Photocatalytic activities of ZnFe2O4/CdS with different loading ratios under simulated visible light irradiation were discussed with malachite green (MG) as a degradation target. The results showed that 20 wt% ZnFe2O4/CdS possessed with the best catalytic activity, and the removal efficiency of MG could reach 96% in 120 min. Mechanistic research indicated that CdS and ZnFe2O4 could form a Type II heterojunction with stable interface, which was effective for separating photogenerated carriers. The increasing active sites of CdS after the modification of ZnFe2O4 also played a key role in improving the efficiency of photocatalysis.

The key to photocatalytic efficient decomposition of VOCs is to significantly improve carrier separation-efficiency of the photocatalyst. Herein, we synthesized a novel photocatalytic composite material of I-deficient BiO1.2I0.6/WO3 by solvothermal method coupling with thermal decomposition. The PL spectrum and photoelectrochemical tests found that WO3 compounded by 40 wt% BiO1.2I0.6 greatly promoted its separation efficiency of carriers. This was mainly caused by the potential difference of band edge between the 40 wt% BiO1.2I0.6 and WO3 driving reverse shift of carriers in their space charge-layer. The 40 wt% BiO1.2I0.6/WO3 achieved 58.8% mineralization ratio in the process of degrading typical VOCs, toluene after 8 h irradiation, which was 15.9 and 2 times those of BiO1.2I0.6 and WO3, respectively. Gaussian calculation and ESR investigation demonstrated that toluene was decomposed by h+ and hydroxyl radical (·OH) under irradiation.

Honeycomb-like graphitic carbon nitride (H–C3N4) with unique morphology has been studied as a promising polymer photocatalyst. Herein, a novel binary metal sulfide constructed with H–C3N4 (Cd0·5Zn0·5S/H–C3N4) was prepared though the facile in situ precipitation method. The characterization data suggest that Cd0·5Zn0·5S quantum dots (QDs) are well dispersed on the macroporous structure of H–C3N4 (156 m2 g−1), which can provide higher surface area, more catalytic active sites and larger interface contact area with accelerating the migration and separation of charge carriers. By taking advantage of 0D/3D heterojunction structure, the Cd0·5Zn0·5S/H–C3N4 dramatically boosts the photocatalytic H2 evolution rate with the visible-light illumination. The Cd0·5Zn0·5S/H–C3N4-3 yields the highest photocatalytic activity of 5145 μmol h−1 g−1, which is 4.3 times as high as that of pure Cd0·5Zn0.5S. Furthermore, Cd0·5Zn0·5S/H–C3N4 composite presents high stability after four recycles. The enhanced visible-light-driven photocatalytic H2 production is attributed to the construction of n-n type heterojunction as well as the large surface area, which can inhibit the agglomeration of Cd0·5Zn0·5S nanoparticles, and efficiently transfer the photoexcited electron-hole pairs in Cd0·5Zn0.5S. Therefore, this work provides a potential way for designing advanced 0D/3D heterojunction.

Ni and carbon materials exhibit remarkable catalysis for the hydriding reaction of Mg. But the underlying mechanism of Ni/C hybrid catalysis is still unclear. In this work, density functional theory (DFT) calculation is applied to investigate the effect of Ni/C co-incorporation on the hydriding reaction of Mg crystal. The morphology and crystal structure of the Ni/C co-incorporated Mg sample show that the co-incorporated structure is credible. The transition state searching calculation suggests that both the incorporations of Ni and C are beneficial for the H2 dissociation. But Ni atom has a dramatic improvement for H2 dissociation and makes the H diffusion become limiting step of the hyriding reaction. The Ni dz2 orbit and H s orbit accept the electrons and combine together compactly, while the Ni dxy orbit is half-occupied. The catalytic effect of Ni on H2 dissociation can be ascribed to the bridging effect of Ni dxy orbit. The incorporation of C can weaken the over-strong interaction between Ni and H which hindered the H diffusion on Mg(0001). The Ni/C co-incorporated Mg(0001) shows the best performance during hyriding reaction compared with the clean and single incorporated Mg(0001).

Aggregation-induced emission (AIE) has been much employed for visualizing material aggregation and self-assembly. However, water is generally required for the preparation of the AIE aggregates, the operation of which limits numerous material processing behaviors. Employing hexathiobenzene-based small molecules, monopolymers, and block copolymers as different material prototypes, we herein achieve AIE in pure organic phases by applying a nonequilibrium strategy, photoexcitation-controlled aggregation. This strategy enabled a dynamic change of molecular conformation rather than chemical structure upon irradiation, leading to a continuous aggregation-dependent luminescent enhancement (up to ~200-fold increase of the luminescent quantum yield) in organic solvents. Accompanied by the materialization of the nonequilibrium strategy, photoconvertible self-assemblies with a steady-state characteristic can be achieved upon organic solvent processing. The visual monitoring with the luminescence change covered the whole solution-to-film transition, as well as the in situ photoprocessing of the solid-state materials.

The introduction of metal–organic framework materials into photocatalysts is considered to be an effective strategy for improving the transfer and separation efficiency of photogenerated electron–h...

We present a novel and facile fabrication of wall-thickness controlled ZrTiO4 nanotubes (ZTNTs) using bacterial cellulose (BC) as a template. Unique porous thin-walls and interconnected channels within ZTNTs contribute a lot to the enhanced photodegradation activity. The roles of the wall-thicknesses in physicochemical properties as well as photocatalytic activities were careful investigated which might extend the synthesis of other nanotubes with higher catalytic performance.

Triptycene covalent polymer (TCP) was fabricated with CdS nanorod to form a novel core-shell nanorod CdS@TCP via a facile in-situ synthesis. A 7 nm thick shell composed of amorphous TCP was homogeneously anchored on the surface of CdS-NR by a self-assembly process, yielding a one-dimensional heterostructure. Characterizations exhibit that CdS@TCP with high surface area can provide abundant surface active sites and intimate contact interfaces for absorbing H2O molecules. The CdS@TCP core-shell nanocomposite as a non-noble metal photocatalyst shows significantly enhanced photocatalytic H2 production activity and excellent photostability. The CdS@TCP-4 indicates the highest photocatalytic H2 evolution rate of 104.51 mmol h−1 g−1, which is approximately 16.2 times than that of pure CdS-NR. Besides, the photoelectrochemical performances of CdS@TCP are measured by using transient photocurrent response, EIS Nyquist plots, open circuit potential as well as Mott-Schottky plots. The improved visible light photocatalytic H2 evolution performance of CdS@TCP is due to its large surface area, and the formation of intimate coaxial heterojunction with n-n type, which can broaden light absorption range, boost the transfer of photoexcited charge carriers, and suppress the photocorrosion of CdS-NR.

Hybrid square tubes wrapping fiber reinforced polymer (FRP) around metallic tubes are excellent structures for both collision energy absorption and lightweight. This paper deals with axial crushing theory of hybrid square tubes wrapped with antisymmetric angle-ply. The energy dissipation mechanism of hybrid square tubes is analyzed based on deformation of metallic square tubes. Considering the effects of stacking sequences of FRP on the crashworthiness and energy absorption, theoretical expressions of the membrane force and fully plastic bending moments per unit length of hybrid squares tube are derived. Then, the expression of mean crushing force of hybrid square tubes wrapped with antisymmetric angle-ply is established. Theoretical predictions compare well with the results of three groups of experiments and forty simulation models. The theoretical calculation presented in this paper can predict the behavior of hybrid square tubes during the conceptual design.

Novel high-efficiency visible-light photocatalyst, silver oxide (Ag2O)-polyimide (PI) photocatalyst is synthesized by a liquid phase reaction method. The obtained samples are characterized by X-ray...

Oriented rutile TiO2 nanorod arrays (TiO2 NRA) were elaborately grown on the conductive mica (C-mica) with Sb-SnO2 seed crystal by a hydrothermal strategy to achieve TiO2 NRA/C-mica composites. The as-obtained samples were characterized by X-ray diffraction, field emission scanning electron microscope, X-ray photoelectron spectroscopy, UV–vis diffuse reflectance spectroscopy and photo-electrochemical measurements. Compared with TiO2 NP/mica, TiO2 NRA/C-mica coated film exhibits more excellent physical barrier ability in the dark, and an enhanced photo-induced current density as well as a more negative photo-potential shift in the light, indicating remarkable photo-cathodic protection for 304 stainless steel (304SS). The distinctive 1D-2D architecture of TiO2 NRA/C-mica facilitates the transmission and separation of photo-induced electron-hole pairs. Furthermore, it's the first time that the TiO2 NRA/C-mica hybrid film is found to possess continuous and stable cathodic protection for the 304SS over a long period in the dark.

Herein, a series of two-dimensional porous CdS sheets supported on bacterial cellulose (BC@CdS) were facilely synthesized through a biotemplate method without using any organic capping agent. Based on the unique 2D porous structure of BC@CdS, visible-light-driven H2 production activity was enhanced by ∼3.5 times compared with pure CdS nanoparticles. Furthermore, the “connecting windows” sizes of BC@CdS sheets were successfully controlled by adjusting the coating time. Our results demonstrate that the connecting window sizes play important role in photocatalytic degradation of methyl orange. To our best knowledge, it is the first time to use BC as a “scaffold” for the controlled growth of 2D porous CdS structures. It is hoped that our current work could widen the strategies for further synthesis of surface-clean 2D materials with controlled porous structures.

An asymmetric zinc phthalocyanine composites ([3α-(OPh-t-Bu)-α-NO2]ZnPc-MWCNTs) have been prepared. The as-prepared composites are characterized via UV–Vis spectroscopy, Fourier transform infrared spectra, X-ray diffraction, scanning electron microscope and transmission electron microscopy techniques. The catalytic performance of [3α-(OPh-t-Bu)-α-NO2]ZnPc-MWCNTs composites are evaluated by studying the catalytic oxidation of styrene. Effects of different solvents and oxidant, mass ratio of composite catalyst and styrene, temperature, time on catalytic activity were also investigated. It can be found that the [3α-(OPh-t-Bu)-α-NO2]ZnPc-MWCNTs composites have better catalytic activity with higher conversion and selectivity. When the mass ratio of [3α-(OPh-t-Bu)-α-NO2]ZnPc-MWCNTs/styrene is 1:15, the highest conversion rate and the optimal selectivity can reach 96.6% and 86.1%, respectively. Moreover, the possible catalytic mechanism of [3α-(OPh-t-Bu)-α-NO2] ZnPc-MWCNTs composites for the oxidation of styrene was discussed.

Although bio-materials are widely used for the adsorption of heavy metal ions, they have low specific surface area, slow adsorption rates, and poor selectivity. To overcome these limitations, in this study, we report a 3D-ordered macroporous ion-imprinted chitosan film (3DOM-IICF); the 3DOM-IICF coupled with a colloidal crystal template and ion imprinting (IIP) technology has been used to absorb copper ions (Cu(II)) present in water. Moreover, polystyrene (PS) micro-spheres and copper templates were added to form a three-dimensional ordered macroporous structure and ion-imprinted sites, respectively. Finally, the film was formed by drying. Adsorption experiments showed the removal of Cu(II) from the 3DOM-IICF in an aqueous solution. The 3DOM-IICF exhibited good adsorption performance under neutral conditions of pH = 7.0, and the adsorption efficiency was high. The maximum adsorption capacity of the 3DOM-IICF was 261.31 mg g−1. The adsorption processes were more consistent with the pseudo-second-order kinetic model and the Langmuir isotherm. The 3DOM-IICF exhibits superior selective adsorption of Cu(II). Moreover, the 3DOM-IICF could be regenerated multiple times, reused as an adsorbent and maintained high adsorption capacity. This kind of imprinted template method has important significance in the selective adsorption of pollutants in bio-materials and is worthy of in-depth research.

Silicon as a high capacity alloying anode material in lithium-ion batteries (LIBs) has recently been reported to have a promising specific capacity suitable for sodium-ion batteries (SIBs). However, the low gravimetric capacity and large volume expansion in traditional electrodes arising from the slurry-coating process has restrained the development. Here, we report the fabrication of a self-supported composite composed of silicon nanocrystals in a 3D hierarchical carbon network as an anode for reversible sodium storage by a three-step process involving electrostatically assisted hetero-assembly, vacuum filtration, and thermal treatment. The silicon nanocrystals decorated with a carbon coating are dispersed in interconnected carbon nanotubes with close contact. The structure provides abundant interfacial active sites for capacitive Na storage. Furthermore, the conductive 3D network of carbon nanotubes and carbon coating provide the high-speed pathways for charge transport and buffer to accommodate the volume change during Na+ insertion/extraction in silicon nanocrystals. As a binder-free anode in SIBs, the self-supported electrode delivers outstanding electrochemical performance such as stable cyclability with a capacity of 80% at a current density of 0.2 A g−1 after 1000 cycles and high-rate capability with a capacity of 105 mAh g−1 at a current density of 2 A g−1. The self-supported Si-based electrode has great potential in high-performance SIBs.

Waste tire rubber has become a severe environmental issue, which calls for a green method to recycle this rubber. Microwave thermolysis serves as an ideal recycling process for used tires. By surveying the dielectric characteristics from 25 to 700 °C under microwave frequencies of 915 and 2466 MHz, the microwave absorption ability of waste tire rubbers was studied. At temperatures below 350 °C, the dielectric characteristics were relatively steady. Both the loss factor and relative dielectric constant (DC) increased sharply with the rise in temperature. The reason for this is the release of volatile substances, which increases the electrical conductivity. The performance of microwave absorption of tire rubber during thermolysis, and thus the efficiency of microwave tire rubber thermolysis, can be largely impacted by the specimen dimension. The calculation of the reflection loss (RL) of the tire rubber specimens suggests that when the waste tire rubber is 5 mm thick, the highest microwave absorption can be achieved at 915 MHz and 592.1 °C, with RL of −17.30 dB. The product after microwave pyrolysis of waste tire rubber comprises 35% carbon black, 40% oil, and 25% gas. Based on this investigation of the optimal condition of microwave absorption, a proper microwave pyrolysis recycling system was designed for waste tire. This system is efficient at recycling the waste tire rubber into valuable carbon black, oil, and gas products.

Removing heavy metal ions from electroplating wastewater is an important environmental engineering problem. Existing methods involve either unaffordable costs or low removal efficiencies. In this s...

In this study, the CdS/CdWO4 composites was synthesized by three steps as the visible-light-driven photocatalyst to achieve the remarkable enhanced photocatalytic hydrogen (H2) production activity (about 2400 μmol/h/g) and excellent photodegradation activity (97%) of malachite green (MG) in 100 min. Compared with pure CdS, 0.5-CdS/CdWO4 composites exhibit 3-fold higher photocurrent density in photocurrent response experiment and smaller charge-transfer resistance in electrochemical impedance spectroscopy (EIS) which manifested the efficacious separation of photo-generated charges. Radical trapping experiments and XPS further demonstrate the transfer of photo-generated charges followed Z-scheme system. This work presents a new design of CdS/CdWO4 composites in formation of Z-scheme heterojunction. Based on the outcomes of UV–vis spectra and Mott-Schottky plots, the photocatalytic mechanism of H2 production and MG photodegradation over CdS/CdWO4 composites under visible-light irradiation was proposed.

A novel ternary heterojunction BiOI@UIO-66(NH2)@g-C3N4 (BiOI@UNCN) was synthesized by in-situ solvothermal-hydrothermal approach, showing superior photocatalytic degradation of RhB and TC under visible-light irradiation. The optimal BiOI@UNCN-40 composite exhibits the highest degradation efficiency of RhB (95%) in 80 min and TC (80%) in 180 min in comparison with pristine BiOI, UIO-66(NH2) and UIO-66(NH2)@g-C3N4. The improved photocatalytic activity of BiOI@UNCN can be ascribed to its improved visible-light absorption range, the large specific surface area based on UIO-66(NH2) as well as the formation of an effective n-p-n type heterojunction driven by Z-scheme mechanism. The formed Z-scheme mechanism at the interface of ternary composite facilitates the separation and transfer of photoexcited charge carrier, which is confirmed from the results of PL and EIS spectra. The photocatalytic mechanism is further proposed based on the trapping experiment, and the transfer process of photoinduced electron-hole pairs is discussed. This work provides an effective strategy for designing a new ternary photocatalytic system toward degradation of organic pollutants.

In this study, we synthesized a novel LaFeO3/AgBr heterojunction via an in-situ precipitation method. The composition, structure, and optical absorption properties of LaFeO3/AgBr were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and ultraviolet-visible diffuse reflectance spectroscopy. The photocatalytic activity of the LaFeO3/AgBr photocatalyst was determined based on the degradation of tetracycline and three types of dyes comprising methyl orange, rhodamine B (RhB), and malachite green. The photocatalytic performance of the LaFeO3/AgBr heterojunction was much better compared with that of the pure AgBr and LaFeO3. It should be noted that Ag nanoparticles were not present in the fresh LaFeO3/AgBr heterojunction. However, according to the XRD and TEM results obtained for 10%-LaFeO3/AgBr, Ag nanoparticles were generated in the LaFeO3/AgBr heterojunction during the photodegradation process, which accelerated the separation of photoinduced carriers in the LaFeO3/Ag/AgBr system. Based on the detection of active species, we propose a Z-scheme photocatalytic and organic dye (RhB) photosensitization mechanism, which also considers the role of Ag nanoparticles in the separation of electrons and holes. The stability of the LaFeO3/AgBr heterojunction was also investigated, which showed that the incorporation of LaFeO3 remarkably improved the photocatalytic activity as well as enhancing the stability of the LaFeO3/AgBr heterojunction by suppressing the photodecomposition of AgBr.

It is crucial and desirable to develop green and high-efficient strategies to regulate solid-state structures and their related material properties. However, relative to solution, it is more difficult to break and generate chemical bonds in solid states. In this work, a rubbing-induced photoluminescence on the solid states of ortho-pyridinil phenol family was achieved. This rubbing response relied on an accurately designed topochemical tautomerism, where a negative charge, exactly provided by the triboelectric effect of a rubber, can induce a proton transfer in a double H-bonded dimeric structure. This process instantaneously led to a bright-form tautomer that can be stabilized in the solid-state settings, leading to an up to over 450-fold increase of the fluorescent quantum yield of the materials. The property can be repeatedly used due to the reversibility of the tautomerism, enabling encrypted applications. Moreover, a further modification to the structure can be accomplished to achieve different properties, opening up more possibilities for the design of new-generation smart materials., Changes in molecular properties due to stimuli response are critically important for the development of new materials. However, most processes are slow or inefficient in the solid state. Here the authors demonstrate property switching in the solid state using a rubbing-induced tautomerism in multiple hydrogen-bonded donor-acceptor couples.

An active site normally locates inside of enzymes, substrates should go through the tunnel to access the active site. Tunnel engineering is a powerful strategy for refining the catalytic properties of enzymes. Here, P450BsβHI (Q85H/ V170I) derived from hydroxylase P450Bsβ from Bacillus subtilis was chosen as study model, which is reported as a potential decarbonylase. However, this enzyme showed low decarboxylase activity towards long-chain fatty acids. Here, a tunnel engineering campaign was performed for modulating the substrate preference and improving the decarbonylase activity of P450BsβHI. The finally obtained BsβHI-F79A variant had a 15.2-fold improved conversion for palmitic acid; BsβHI-F173V variant had a 3.9-fold improved conversion for pentadecanoic acid. The study demonstrates how the substrate preference can be modulated by tunnel engineering strategy.

This study is devoted to finding a solution to an important problem of increasing the accuracy of assessing the fatigue stability of composites based on recycled asphalt concrete. Another problem for solving was a selecting optimal and effective ways to improve their physical–mechanical properties during modification by polymers. For experimental work, a new indicator reflecting the strength of elastic structural bonds and the specific number of viscoplastic bonds was used as a criterion for fatigue stability of bituminous-cement composites. As shown by the results of the research, fatigue (cyclic) stability has an increasing trend with the growth of these parameters. As a result of processing data from experimental studies of the structural characteristics of composites, a comparative analysis of the effectiveness of modification of cold recycled mixes by styrene acrylate and epoxy resin was performed. It was established that the composites modified with styrene acrylates have a higher relaxation ability, which is reflected in the increase in the number of cycles to failure when testing for cyclic stability. It is also noted that with an increase in the content of epoxy resin in the composition of mixes, the increase in stiffness occurs much more strongly in comparison with an increase in their relaxation ability. At the same time, the efficiency of modification of cold recycled mixes with epoxy resins is significantly increased with the preliminary preparation of asphalt granulate (RAP), for example, during its plasticization with soy epoxidized oil. This work also allowed us to outline some areas of development of the methodological foundations for assessing the cyclic and fatigue stability of composites based on cold recycled mixes.

A noble metal-free photocatalyst, the porous flower spherical Ni5P4 coupled g-C3N4 quantum dots (GCNQDs) was prepared by a simple ultrasonic impregnation method for the degradation of norfloxacin in wastewater. The GCNQDs exhibit obvious quantum confining effect due to its small particle size. For Ni5P4, its large specific surface area is conducive to the adhesion of GCNQDs, so that GCNQDs/Ni5P4 composite photocatalysts have excellent photocatalytic performance. In addition, the important role of porous Ni5P4 in promoting electron-hole separation and photocatalytic performance was confirmed by experiments and density functional theory (DFT) calculations. It was found that the GCNQDs and Ni5P4 formed a Shottky junction. At the same time, the GCNQDs/Ni5P4 composite photocatalysts showed good stability in the cycle test, which made it become a kind of green, efficient and repeatable photocatalytic material. This work proposed the degradation mechanism of GCNQDs/8% Ni5P4 composite photocatalysts and the possible degradation path of norfloxacin, providing a new idea for the design of highly active composite photocatalysts.

In this work, we developed a facile method for direct fabrication of cross-linking polymer coating from monomers via triethylamine gas-mediated thiol-ene chemistry. Combined with fluidized bed coating technology, we used this method to prepare a kind of biobased polymer coated slow-release fertilizer. The polymer coating was synthesized from low-cost, biodegradable, and renewable castor oil. The nitrogen-release behavior, the promotion on seed germination and early-stage seedling growth of polymer-coated urea granules were investigated. The coating method demonstrated in this research could provide a new perspective for the development of a new generation of biobased slow-release fertilizer.

Carbon materials have attracted increasing attention for hydrogen storage due to their great specific surface areas, low weights, and excellent mechanical properties. However, the performance of carbon materials for hydrogen absorption is hindered by weak physisorption. To improve the hydrogen absorption performance of carbon materials, nanoporous structures, doped heteroatoms, and decorated metal nanoparticles, among other strategies, are adopted to increase the specific surface area, number of hydrogen storage sites, and metal catalytic activity. Herein, Li–fluorine codoped porous carbon nanofibers (Li–F–PCNFs) were synthesized to enhance hydrogen storage performance. Especially, perfluorinated sulfonic acid (PFSA) polymers not only served as a fluorine precursor, but also inhibited the agglomeration of lithium nanoparticles during the carbonization process. Li–F–PCNFs showed an excellent hydrogen storage capacity, up to 2.4 wt% at 0 °C and 10 MPa, which is almost 24 times higher than that of the pure porous carbon nanofibers. It is noted that the high electronegativity gap between fluorine and lithium facilitates the electrons of the hydrogen molecules being attracted to the PCNFs, which enhanced the hydrogen adsorption capacity. In addition, Li–F–PCNFs may have huge potential for application in fuel cells.

CdS quantum dots (QDs) were decorated onto phosphorus-doped hexagonal g-C3N4 tube (P-CNT) to form a novel high-preformance photocatalyst (CdS QDs/P-CNT) via an in-situ oil bath approach. The ultra-small CdS QDs with the average diameter of ~9 nm are homogeneously anchored on the both external and internal surface of P-CNT hollow channel (~25 μm), yielding a type of zero-dimensional (0D)/one-dimensional (1D) heterojunction. The CdS QDs/P-CNT-1 exhibits the maximum photocatalytic H2 evolution rate of 1579 μmol h−1 g−1 under visible-light irradiation, which is 31.6, 6.8, 4.7 and 3.1 times higher than P-CNT, CdS, CdS/BCN and CdS/CNT, respectively. The improved photocatalytic activity of CdS QDs/P-CNT is primarily attributed to large surface area, P doping and formed 0D/1D heterojunction, which can broaden the light absorption, narrow the band gap, activate the H2O molecule and promote the spatial charge separation. Moreover, the DFT calculation coupled with experiment (Mott-Schottky curves) illustrates the electron transfer behavior of CdS QDs/P-CNT, showing that the Cd-1 site should be the main active center and P doping is beneficial to increase H2 production. This work provides a new strategy to design of highly active 0D/1D photocatalyst for photocatalytic H2 production.

The artificial Z-scheme photocatalysts, simulating the natural photosynthesis, enables more efficient utilization of solar energy for sustainable fuel production. A novel direct Z-scheme CoWO4/CdS binary photocatalyst is synthesized by an in-situ hydrothermal method, and the enhanced activities of H2 production and dye degradation are attained. The rate of H2 production is 15.91 mmol/h/g, which is 24-fold higher than CdS. The CoWO4/CdS composites exhibited outstanding stability after five consecutive reactions. Meanwhile, the photocatalytic removal efficiencies of MG are about CdS

Nitrogen oxide (NOx) is one of the world’s major air pollutants. Thus, utilizing inexpensive mineral materials to develop an efficient and low-temperature denitrification catalyst is of great significance. In the present work, palygorskite (Pal)-supported perovskite-type LaFe1-xNixO3 (x = 0.1–0.9) nanocomposites are prepared by a facile sol-gel method. Extensive tests are employed to characterize the textural and structural properties of samples. It is determined that perovskite particles are well dispersed on the surface of Pal with excellent NH3 adsorption. The impacts of various Ni doping on the NOx conversion under visible light irradiation are investigated. Results indicate that when x is less than 0.4, LaFe1-xNixO3 remains a perovskite solid solution supported uniformly on the Pal surface. When x is beyond 0.4, LaNiO3 phase co-precipitates and forms a coherent heterojunction of LaNiO3/LaFe0.6Ni0.4O3 on Pal. Photo-assisted selected catalytic reduction (Photo-SCR) of NO results show that the denitrification performance varies with the Ni content, and more than 90% of NO molecules can be reduced when x = 0.5 in low temperature range of 150–250 °C.

A series of cobalt phthalocyanine (CoTNPc)/SnIn4S8 composites with different mass proportions were prepared by ultrasonic method. The obtained composites have been characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, Fourier transform infrared spectra diffuse reflection spectroscopy, Raman spectroscopy and photoluminescence. It was found that the photocatalytic performance of 10%-CoTNPc/SnIn4S8 composites was 3.18 times larger than that of bare SnIn4S8 under 100 min visible-light irradiation. More importantly, the 10%-CoTNPc/SnIn4S8 composites possessed the maximum photocatalytic activity whose degradation rate approached to around 99.2% and the cyclic experiment verified the stability of CoTNPc sensitized SnIn4S8 composites. In addition, some typical scavengers were added to speculate the potential photocatalytic mechanism during the photocatalytic oxidation process. This photocatalytic enhancement of CoTNPc/SnIn4S8 composites was attributed to its efficient charge transfer and inhibition of the recombination around electron–hole pairs.

Commercial V–Ti oxide catalysts are widely used in the selective catalytic reduction (SCR) of NOx, however it requires high reaction temperature and poisonous V components. In addition, the deactivation induced by the SO2 and H2O in the flow gases has restricted its extensive applications. To address those problems, a series of Fe2O3/SmFeO3/palygorskite (Pal) with various Fe/Sm molar ratios (nFe/nSm) were prepared by a sol–gel method for photocatalytic assisted SCR of NOx at low temperature. The morphology and structural properties of as-prepared catalysts were characterized by various measurements. Results indicated that the rational addition of Fe species could not only formed Z-scheme heterostructure Fe2O3/SmFeO3 with high redox property, but also effectively restrained the generation of sulfate species. The catalysts achieved the highest 95% conversion rate and 100% N2 selectivity when the nFe/nSm = 2 with remarkable SO2 and H2O resistance.

A novel class of CdS@UIO-66-NH2 core shell heterojunction was fabricated by the facile in-situ solvothermal method. Characterizations show that porous UIO-66-NH2 shell not only allows the visible light to be absorbed on CdS nanorod core, but also provides abundant catalytic active sites as well as an intimate heterojunction interface between UIO-66-NH2 shell and CdS nanorod core. By taking advantage of this property, the core-shell composite presents highly solar-driven photocatalytic performance compared with pristine UIO-66-NH2 and CdS nanorod for the degradation of organic dyes including malachite green (MG) and methyl orange (MO), and displays superior photostability after four recycles. Furthermore, the photoelectrochemical performance of CdS@UIO-66-NH2 can be measured by the UV–vis spectra, Mott-Schottky plots and photocurrent. The remarkably enhanced photocatalytic activity of CdS@UIO-66-NH2 can be ascribed to high surface areas, intimate interaction on molecular scale and the formation of one-dimensional heterojunction with n-n type. What’s more, the core-shell heterostructural CdS@UIO-66-NH2 can facilitate the effective separation and transfer of the photoinduced interfacial electron-hole pairs and protect CdS nanorod core from photocorrosion.

Metal–organic frameworks (MOFs) have been attracting considerable attention and present a great potential in photocatalytic water treatment, paving the way for building efficient and environmentally-friendly photocatalysts. In this work, a stable photoactive UIO-66(NH2) incorporated with Ag/AgBr photocatalyst has been successfully fabricated through the sonication-assisted deposition–precipitation technique and exhibits remarkable photocatalytic activity for the degradation of methyl orange (MO) dye under visible light irradiation (λ ≥ 420 nm). The as-prepared photocatalysts are characterized by powder X-ray diffraction, field-emission scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy, BET, X-ray photoelectron spectra, UV–vis diffuse reflectance spectra, and photoluminescence spectra. Moreover, the obtained Ag/AgBr@UIO-66(NH2) photocatalyst shows an outstanding recyclability. The enhanced photocatalytic performance is attributed to the favorable band alignment between UIO-66(NH2) and AgBr mediated by Ag NPs. The surface plasmon resonance (SPR) effect of Ag NPs make the electrons in Ag NPs preferentially transfer to AgBr, which facilitates the charge transfer of Ag/AgBr@UIO-66(NH2).

Rare earth elements (REEs) are critical materials to many cutting-edge technologies but are difficult to separate from one another because of their chemical similarity. We present ionic imprinted mesoporous bilayer films (IIBFs) as an ideal adsorbent for selective separation of neodymium (Nd) and dysprosium (Dy) from sintered neodymium magnets. IIBFs were prepared according to dual-template docking oriented ionic imprinting (DTD-OII). Due to different imprinted compositions of bilayer films, IIBFs exhibited high specific surface area, fast binding equilibrium, and Janus properties for simultaneous selective adsorption of different rare earth ions, which made our imprinted bilayer mesoporous films a specialized adsorbent for adsorption of Nd(III) and Dy(III) at the same time. The adsorption capacities of optimized IIBFs were 17.50 mg g−1 for Dy(III) and 12.15 mg g−1 for Nd(III) at pH = 4.0. Moreover, we grafted thermo-responsive polymer on the one surface of IIBFs to realize controlled release of Nd(III) and Dy(III) by temperature. IIBFs demonstrate a high degree of reusability by cycling experiments by DTD-OII, which develop their promising applications for the REE recycling and separation industry.