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Cost-efficient and durable oxygen evolution catalysts are in great demand, which are dominated not only by the component of the electrocatalysts but also by their molecular structure and crystallinity. Herein, we developed an efficient cobalt–vanadium spinel-type electrocatalyst with an extremely high concentration of Co 3+ ions by tuning the balanced vanadium ions’ concentration in crystallinity-modulated Co 2–xV xO 4 nanoplates. This resulted in the lowest overpotential of 240 mV at 10 mA/cm 2, the smallest Tafel slope of 45 mV dec –1, and a current density of 100 mA/cm 2 at an overpotential of 280 mV for water oxidation, which is remarkably 20 times better than that of the benchmark RuO 2 catalyst, along with excellent stability. Such excellent performance is due to the very high Co 3+/Co 2+ ratio of 2.84 achieved in situ in the low-crystallinity Co 2–xV xO 4 (LC-Co 2–xV xO 4) sample, which is 40% higher than that of the widely reported Co 3O 4, as evidenced by both operando X-ray absorption near-edge spectroscopy and in situ X-ray photoelectron spectroscopy. These findings stimulate the opportunities to explore Co 2–xV xO 4 as a class of nonprecious-metal-based efficient OER electrocatalysts.

Layered perovskite (La1−xSrx)2CoO4±δ (x = 0.3, 0.4, 0.5) oxides were prepared using sol–gel route and evaluated as the cathode materials for intermediate-temperature solid-oxide fuel cells. (La1−xSrx)2CoO4±δ has a tetragonal structure with space group of I4/mmm in all cases of x levels. The average thermal expansion coefficient of (La1−xSrx)2CoO4±δ is relatively low and slightly increases with x, which can be ascribed to the sway of Sr doping on the spin-state transition of Co ions. X-ray photoelectron spectroscopy and thermogravimetric analysis show that Co ions exist in mixed oxidation states, but the lattice oxygen content considerably varies with x. Regarding transport property, (La1−xSrx)2CoO4±δ behaves like a semiconductor in the temperature range of 200–800 °C, and the electrical conductivity significantly increases with x. As one of the most important results, electrochemical performance of (La1−xSrx)2CoO4±δ cathode is affected by x in a complex manner, and x = 0.4 cathode, i.e., La1.2Sr0.8CoO4±δ, has the most favored area-specific resistance of 0.062 Ω cm2 and the highest power density of 630 mW cm−2 in an electrolyte-supported single cell at 800 °C, showing a rapid kinetics toward oxygen reduction reaction. This study demonstrates that the structural, transport, thermal, and electrochemical properties of (La1−xSrx)2CoO4±δ cathodes significantly depend on the La/Sr ratio at the A-site of lattice. Rietveld refinement profile and temperature-dependent electrochemical performance for La1.2Sr0.8CoO4±δ cathode material

By employment of a flexible benzoimidazole-type ligand of 1-(2-(1H-benzoimidazol-1-yl)ethyl)-1H-benzoimidazole (beb), two coordination polymers (CPs) of Zn(II) and Co(II) namely, {[Co(beb)(dmglut)]}n (1) and {Zn2(beb)2(hipt)2(H2O)1.5(MeOH)}]n (2) have been produced in the existence of distinct dicarboxylate ligands and metal ions. The measurements of luminescence reveal that the Zn(II)-containing complex 2 can determine 2,4,6-trinitrophenol (TNP) in DMF which possesses high selectivity and sensitivity. For the treatment of Alzheimer’s disease, complexes 1 and 2 were synthesized as above. Their treatment activity on the Alzheimer’s disease was evaluated, and the specific mechanism was investigated as well. Western blot was used to detect the accumulation of Amyloid protein in neurons. Then, the real time RT-PCR was implemented to assess autophagy related genes expression levels.

Iron-based phosphate materials have been employed as cathodes for sodium-ion batteries (SIBs) because of their low cost and environmental friendliness, but the electrochemical performance of this k...

In recent years, research on the relationship between innovation and corporate social responsibility (CSR) has become the primary focus of the relationship between the enterprises, society and ecological environment. An increasing number of scholars have had in-depth discussion on the balance between financial profits and social value creation. This article draws data from the foreign database Web of Science (WOS), and uses the visual analysis software citespace to get a knowledge map of the literature. Through quantitative analysis, multidisciplinary analysis, and co-citation analysis of the literature, among which, co-citation analysis refers to keyword co-occurrence analysis, etc., the frontier characteristics, research hotspots and future trends of the relationship between innovation and CSR have been initially formed. The research results support the conclusions that: Firstly, the research on the relationship between innovation and CSR has been gradually expanded, and the impetus and influence of external factors on innovation has gradually given way to the combined effect of internal factors; secondly, the expanded definition of CSR has enriched the knowledge basis for research, however selecting many indicators has become a problem for the related research; and finally, this article has summarized the research standards and research perspectives on innovation and CSR and analyzed the research prospects in related fields.

Abundant flake-porous Na3Fe2(PO4)3 has been prepared via a simple spray drying method. As a cathode material in sodium-ion batteries (SIBs), the galvanostatic charge/discharge test results indicate...

In this study, the effects of carbon quantum dot (CQD) doping on the photocatalytic performance of semiconductor BiOCl microspheres were investigated. Highly dispersed CQDs with up-conversion luminescence properties were prepared using the hydrothermal method, and visible-light-responsive CQDs@BiOCl photocatalysts with regular morphology were prepared via CQD doping. Scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and ultraviolet–visible (UV–Vis) spectroscopy were used to investigate the morphology and light absorption properties of the materials. The degradation rate of rhodamine B (RhB) was 76.1% after 180 min of visible-light irradiation when CQDs@BiOCl were used and only 19.4% when pure BiOCl was used. The photoluminescence (PL), UV–Vis diffuse reflectance spectra (UV–Vis DRS) and electron paramagnetic resonance (EPR) results were analyzed to determine the possible reasons for the increased photocatalytic activity of CQDs@BiOCl microspheres. The results showed CQD doping expanded the visible light absorption range, CQDs exhibited fast photoinduced electron transfer, and CQDs@BiOCl possessed high mesoporosity, which promoted the effective separation of photogenerated electron–hole pairs. In addition, the microsphere structure of CQDs@BiOCl exhibited a larger specific surface area and a more regular morphology than its sheet-like structure. These features increased the number of photocatalytic reaction sites and the surface adsorption of the catalyst. In addition, the electronic conjugated structure of CQDs was demonstrated to function as an effective electron trap. CQD doping effectively inhibited the photogenerated electron–hole pair recombination of the composite photocatalyst, which enhanced the photocatalytic performance of the system.

A novel NASICON-type K0.24Na2.76Fe2(PO4)3 (K0.24NFP) is synthesized via a simple solid-state reaction method. K-doped method can enlarge lattice distance and restrain the structure dilapidation from Na3Fe2(PO4)3 to Na5Fe2(PO4)3. Comparison with undoped-Na3Fe2(PO4)3 (NFP) sample (82.1 mAh g−1), K0.24NFP electrode shows a 101.3 mAh g−1 discharge capacity at 10 mA g−1, which up to 97% of theoretical capacity. As for rate capability performance, a high reversible capacity of 73.6 mAh g−1 at 1000 mA g−1. The cycle stability performance measurement results indicate that the discharge capacity of K0.24NFP electrode is up to 93.7 mAh g−1 after 500 cycles at 100 mA g−1. The excellent electrochemical performance is attributed to the improvement of structural stability and the highest intercalation-deintercalation kinetic of sodium-ions (DNa+ = 3.98 × 10−11) due to K-doped. Hence, the K-doped iron-based phosphate (K0.24Na2.76Fe2(PO4)3) should be a potential cathode material in sodium-ions batteries for scale energy storage.

The use and control of the extraordinary optical transmission through subwavelength hole arrays has enormous application potential in photonic devices. In this paper, we propose a subwavelength hole array with inner tunnels, for which the Smith-Purcell radiation (SPR) with this enhanced transmission phenomenon in THz is excited when the transmission peak locates in the SPR band. The SPR is monitored using particle-in-cell simulations in order to analyze the mechanisms responsible for improving the radiation coherence. Analysis of the electron energy loss reveals that the proposed subwavelength hole array with inner tunnels outperforms a conventional subwavelength grating array with respect to SPR generation efficiency. As SPR plays a significant role in research on particle diagnosis and terahertz radiation sources, the performance of the proposed structure suggests that it has high application potential.

With the rapid development of infrastructure construction, it is an inevitable trend to replace natural sand in short supply with manufactured sand to meet sustainable development. In this paper, the relationship between the particle shape characteristics of manufactured sand and concrete performance is discussed using a morphological analysis and concrete experiments. The particle shape parameters of five types of manufactured sand were obtained by using the aggregate image measurement system (AIMS) and digital image processing (DIP) techniques, and the correlations between different parameters were analyzed. Moreover, the properties of concrete with the five kinds of manufactured sand were tested. The results show that particle size and type have a significant impact on particle shape parameters. Particle shape parameters, especially angularity, correlate well with the workability and compressive strength of concrete while having little effect on the durability of concrete. An accurate understanding of the morphological characteristics of manufactured sand is conducive to the optimization of concrete mix designs. Therefore, it is suggested that a manufactured-sand shape test be included in aggregate specification.

Iron-based phosphates as a low cost and high structural stability cathode materials for sodium ion batteries (SIBs) have been widely studied. However, the working potential basing on Fe3+/Fe2+ redox is very low (less than 3.05 V vs. Na/Na+), which has obviously affect on the energy/power density. In this work, we choose the non-precious metal manganese (Mn) to improve the working potential of Na3Fe2(PO4)(P2O7) (NFFPP). A series of mixed-phosphate Na3Fe2-xMnx(PO4)(P2O7) (x = 0.0, 0.5, 1.0, 1.5 and 2.0) compounds are firstly proposed as cathode materials for SIBs. After optimization, the as-prepared Na3FeMn(PO4)(P2O7) (NFMPP) could deliver a higher average working potential of 3.27 V (vs. Na/Na+) with a theoretical capacity of 120 mAh g-1. Furthermore, the carbon coating NFMPP cathode shows a reversible initial specific capacity of 105 mAh g-1 at 0.1 C with a corresponding coulombic efficiency of 99%. The in-situ XRD and ex-situ XPS results indicate that this cathode material goes through the reversible redox Fe3+/Fe2+ and Mn3+/Mn2+ with a reversible two Na-ion insertion/deinsertion process.

Smith-Purcell radiation is a kind of moving dipole oscillation radiation. In the subwavelength hole array, there are two-dimension dipole oscillations to happen when the e-beam is moving through the holes in a beam channel. It leads to the Smith-Purcell radiation energy enhanced, compared to one dipole oscillation in electron beam moving above period occurred metal surface. In addition, the dipole oscillation radiation takes place inside the hole, so the hole also plays a role to resonant the radiation so that the Smith-Purcell radiation has a good direction. Therefore, the radiation of two-dimension dipole oscillations in subwavelength hole array form a kind of Smith-Purcell radiation with intensity enhanced and the radiation direction tuned. It has potential to develop the vacuum electrons device based on Smith-Purcell radiation, such as Orotron, on-table THz free electron laser.

In this study, 18S rRNA high-throughput sequencing was applied to investigate the eukaryotic community in a full-scale drinking water treatment plant. Eukaryotic species and microbial functions in raw water and filter biofilms were identified by metagenomic sequencing. The eukaryotic species richness and diversity presented declining trends throughout the treatment process. The lowest eukaryotic species richness was observed in disinfected water. Arthropoda, Ciliophora, Ochrophyta, and Rotifera were the dominant eukaryotic phyla and exhibited high variations in relative abundance among the different treatment units. Sedimentation significantly decreased the abundance of all eukaryotes except Arthropoda. Biological activated carbon (BAC) filtration and chlorine disinfection exerted strong effects on community composition. The eukaryotic communities in water were distinct from those in filter biofilms, as were the communities of different filter biofilms from each other. In contrast, communities were functionally similar among different filter biofilms, with the category metabolism being the dominant category represented, within which amino acid transport and metabolism (E) and energy production and conversion (C) dominated among subcategories. Seventy-one eukaryotic species pathogenic to humans were identified in raw water and filter biofilms. Quantitative PCR (qPCR) results showed that Acanthamoeba spp. and Vermamoeba vermiformis were present during some treatment processes, with concentrations of 12-1.2 × 105 copies/mL and 1 copy/mL, respectively. Neither of the two pathogenic amoebae was found in disinfected water. Canonical correspondence analysis (CCA) showed that pH was the most important environmental factor affecting eukaryotic community composition. Overall, the results provide insights into the eukaryotic community diversity in drinking water treatment plants and the potential eukaryotic hazards involved in drinking water production.

Introducing secondary metal ions into host electrode materials may result in extra redox sites and regulating the electronic structure to increase electrochemical properties. With the assistance of microwave, Mn cation was in-situ isomorphism doped into porous CoCo2O4 nanowires during a hydrothermal process. Ex-situ characterizations reveal that the doped Mn2+ and Mn3+ in CoCo2O4 provides additional redox reaction by forming reversible Mn4+, which effectively improved electrochemical storage capacity. The added redox reaction of Mn cations is also helpful to effectively suppress the water-splitting, which expanded the operating voltage window. As a result, the as-obtained Mn-doped CoCo2O4 nanowire array electrodes exhibited an enlarged specific capacity (1528.0C g−1/424.4 mA h g−1 at 1 A g−1) with a widened operating voltage window of 1.1 V and superior cycling stability (91.5 % retention after 5000cycles). Correspondingly, the battery-supercapacitor hybrid device constructed by Mn2CoCo2O4 porous nanowire array electrode and biomass-derived N doped porous carbon delivered a stable working voltage of 1.9 V and superior energy density of 58.6 Wh kg−1 at power density of 950 W kg−1 as well as excellent stability (83.7 % specific capacity retained at 10 A g−1 for 8000cycles). This work provides a feasible route for the construction of energy storage devices with high energy density and high power density.

With the new municipal solid waste classification policy implemented in China, attention on achieving the waste-to-energy disposal of “dry waste” has been growing. Pyrolysis conversion of organic waste into value-added chemicals is a promising method to treat solid waste. However, after removing the non-combustible components of “dry waste”, the obtained high-organic solid waste (HSW) contains various heavy metals, which requires urgent attention during thermochemical conversion. To mitigate heavy metals risk, kaolin was employed as additive during HSW pyrolysis, and intercalation–exfoliation and thermal activation modifications were performed on the kaolin to further immobilize and stabilize heavy metals in the derived chars. The characterization results illustrated that the interlayer spacing, pore volume and diameter of kaolin were expanded after intercalation–exfoliation modification, providing more opportunities for the adsorption of metals. The thermal activation method favored the transformation of kaolin into metakaolin via dehydroxylation to enhance its nonhexacoordinated Al proportion and chemisorption. During 450–650 °C, kaolin exhibited an effective solid enrichment performance for targeting heavy metals, and the intercalation–exfoliation and thermal activation modification further enhanced the adsorption capacity of the kaolin for Cd, Cr, Pb and Cr, Cu, Pb, Zn, respectively. Compared with Cu and Zn, additives demonstrated better stabilization effects for Cd, Pb, and Cr, transforming more bioavailable fractions to the residual speciation. Overall, a higher pyrolytic temperature (650 °C) and the addition of effective additives could simultaneously increase the residual fraction and decrease the bioavailable fraction of heavy metals in HSW-derived chars, reducing the potential ecological risk.

Agricultural management measures, including tillage, considerably alter the rhizosphere fungal community; however, traditional snapshot sampling fail to represent the rhizosphere fungal community patterns over time. Here, we conducted a continuous study of wheat rhizosphere fungal communities through long-term tillage experiments (consisting of conventional and conservation tillage) to clarify tillage and growth stage effects. Tillage practices always affected rhizosphere fungal communities (R2 = 18%), and these effects significantly differed between plant growth stages. Drastic changes in plant phenotypes during the growing season may have driven the changes in rhizosphere fungal communities. Specifically, in the tillering stage (the early period of wheat growth), plant traits dynamics and the abundance of two crop-tillage sensitive modules were highly correlated. The conservation tillage abundant module was mainly composed of saprotrophs, whereas pathogens constituted the majority in modules enriched by conventional tillage. These results indicate that it is possible to influence the rhizosphere fungal community structure and function through agricultural management mediated by plant growth. Manipulation of tillage-sensitive OTUs and early rhizosphere fungal community modules can provide new opportunities for developing sustainable and highly productive agroecosystems.

Herein, we design an O-incorporated hierarchical NiCoP/Ni2P hybrid electrodes (O-NiCoP/Ni2P) through a simple progressive phosphatization and dip-coating strategy to overcome the additional cost caused by heteroatom doping. The resulting O-NiCoP/Ni2P displays an ultra-low overpotential of 58 mV at 10 mA cm−2 and long-term stability over 24 h for efficient alkaline hydrogen evolution reaction (HER). Based on the density functional theory simulations, the O doping is beneficial to optimize the free energy of hydrogen/water absorption, which accelerates the HER process. Besides, the strong coupling of O-NiCoP/Ni2P has a positive effect on the electron transfer, thereby improving its catalytic performance. This work provides a potential pathway to the rational design of transition-metal phosphides based HER electrocatalysts and element-doping for energy conversion applications.

The recycling ratio of industrial solid waste, e.g., steel slag (SS), phosphogypsum (PG) is still comparatively low in developing countries. This work aims to utilize industrial solid waste in a sustainable slow-setting slight-expansive road base course binder (RBCB) production involving the performance regulation, hydration characteristics and practical application. The results indicates that RBCB obtained the ideal retarding effect without additional retarder and avoided the strength loss which caused by the fast hardening during the rolling compaction process. The relatively high content of PG preferably stimulated the pozzolanic activity of fly ash (FA), and more effectively compensated the shrinkage through inhibiting the conversion of AFt to AFm in the later hydration stage. In addition, SS adjusted the setting time, improved the strength and regulated the expansion ratio of RBCB. Each kilometer of road base course absorbed 688.8 t solid wastes and saved 6.53% cost of materials compared with P·S 32.5 (Portland slag cement, strength grade is 32.5) in practical application. Excellent pavement performance, obvious environmental and economic benefits were achieved in the field experiment of RBCB containing high solid wastes. This investigation provides a promising and value-added way for the utilization of various original solid waste.

Potassium (K) has a significant effect on wheat yield and quality. Owing to the limitations of irrigation and production costs, soil-based applications of potassium fertilizer are not performed in wheat production on the Loess Plateau of China. In the late growth stage of wheat, potassium deficiency occurs even under sufficient nitrogen/phosphorus (N/P) levels, so it is necessary to supplement potassium through foliar spraying. However, there are few studies on the effect of the foliar application of potassium fertilizer (KFA) on wheat quality. Field experiments were conducted at two experimental sites for 2 years to study the effects of different potassium fertilizer application levels and periods on wheat yield and quality. The results showed that KFA had no significant effect on the yield of the wheat variety Xinong 20 (XN20) but increased the yield of the wheat variety Xiaoyan 22 (XY22). The improvement effect of KFA on the wet gluten content and stabilization time (ST) of XN20 was better than that on these parameters of XY22, while the sedimentation value (SV) and formation time (FT) showed the opposite trend. KFA significantly reduced the albumin content of the two varieties but had no significant effect on the globulin content. Compared with that at the other two stages, the potassium application in the form of potash fertilizer spray at a concentration of 60 mmol L−1 (K2) at the flowering stage (BBCH 65) significantly increased the protein content, wet gluten content, SV and gluten protein content in XN20 grains, whereas the application at 10 days after flowering (AA10, BBCH 71) at the K2 concentration was more beneficial to prolonging the dough FT. For XY22, the application of potassium fertilizer at the K2 concentration at the flowering stage increased the wet gluten and gluten protein levels and dough development time. There were significant genotypic differences in the composition and content of HMW-GS between the two varieties. KFA significantly increased the levels of the 1, 7 + 8, and 4 + 12 subunits in XN20 and the 1 subunit in XY22, but had no significant effect on the 2 + 12 subunit in XY22. Partial least squares path modelling (PLS-PM) analysis showed that the processing quality indexes (SV, FT, ST) and gluten protein and HMW-GS levels were regulated by the potassium fertilizer foliar spraying stage and concentration and revealed in part that KFA affected the processing quality by affecting the HMW-GS content.

In this research, a composite material (MWCNT@BiVO4) was prepared using a one step hydrothermal method. The prepared composite material was characterized by energy-dispersive X-ray analysis, X-ray diffraction, scanning electron microscopy, EDS, UV-Vis diffuse-reflectance spectroscopy, electron spin resonance (ESR), X-ray photoelectron spectroscopy, and photoluminescence spectroscopy. The scanning electron microscopic images showed that MWCNTs were successfully embedded into BiVO4. MWCNT@BiVO4 showed a strong visible-light absorption capacity, high efficiency for electron–hole separation, and excellent stability. The degradation test of RhB was conducted under visible light irradiation. Compared with BiVO4 (K = −0.05657) and P25 (K = −0.03227), MWCNT@BiVO4 (K = −0.11894) realized the highest removal ratio of Rhodamine B (RhB) under visible light irradiation, therefore, MWCNT@BiVO4 might be promoted to practical applications. The stability of MWCNT@BiVO4 was also verified via recycling and reusing experiments. After 5 cycles, MWCNT@BiVO4 could still maintain the removal rate of RhB at 95.96%. In addition, this paper deduced the growth mechanism of MWCNT@BiVO4 and the degradation mechanism of RhB, proving that MWCNT@BiVO4 can be used in future practices.