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Investigating the constituents of active catalysts is crucial for the advancement of ORR electrocatalysts that are both high in performance and stability, aiming to supplant the expensive platinum-based alternatives, yet this task continues to be a persistent challenge. Firstly, HA nanoplates of hydroxyapatite nanocontainers were decorated with zeolite imidazole salt framework (named as HA-ZIF) by hydrothermal synthesis method, and then Co-based imidazole zeolite framework decorated with Zn group was synthesized by simple self-assembly method, and it was calcined at different temperatures. Finally, the ORR performance obtained samples (named as Co2(PO4)2@NC-800, Co2(PO4)2@NC-900 and Co2(PO4)2@NC-1000) was tested by cyclic voltammetry (CV) and linear scanning voltammetry (LSV), and the morphological and structural characterization of composite catalysts at different temperatures were analyzed by PXRD and SEM. It was found that the Co2(PO4)2@NC-900 had the best catalytic performance. The study presents a flexible approach for creating versatile non-precious catalysts applicable to various energy-related electrocatalytic processes.

All-inorganic lead-free layered A3B2X9 perovskites have recently emerged as potential candidates for the development of high-performance perovskite-based optoelectronic and photovoltaic devices. However, there is still a lack of a deep understanding of the phase stability mechanism and optoelectronic properties of A3B2X9 perovskites, which severely limits their device applications. Herein, using density functional theory calculations, we report the phase stability, electronic dimensionality, and optoelectronic properties of fifteen A3B2X9 perovskites with two different structures: hexagonal (H) and trigonal (T) phases. Our calculation results indicate that the phase stability of A3B2X9 perovskites originates from a delicate competition between the B–X bonding interactions and interlayer BX6 octahedral coupling. Moreover, the T-phase perovskites exhibit smaller bandgaps, lower carrier effective masses, and higher absorption coefficients than H-phase ones due to higher electronic dimensionality. Benefiting from optimal bandgaps and higher absorption efficiency, T-phase perovskites show a higher power conversion efficiency (PCE) and the maximum PCE of T-phase Cs3B2I9 (B = Sb, Bi) reaches ∼20%. Owing to weak interlayer interactions, two-dimensional T-phase perovskites can also be exfoliated from their bulk and they exhibit layer-dependent electronic and optoelectronic properties due to the quantum confinement effect. These findings offer an in-depth understanding of phase-dependent electronic dimensionality and optoelectronic properties of A3B2X9 perovskites, highlighting their huge potential for use in integrated photovoltaic devices. [ABSTRACT FROM AUTHOR]

The design and construction of functional interlayers for lithium–sulfur (Li–S) batteries has attracted much attention and was demonstrated to be effective to alleviate the notorious "shuttle effect." An often neglected issue is that the introduction of interlayer will reduce the overall energy density of the battery. In this work, we report a sulfur-infiltrated mesoporous silica/carbon nanotube (CNT) composite as an interlayer for Li–S batteries. The mesoporous silica with large surface area (842 m2 g−1) and pore volume (0.85 cm3 g−1) can not only ensure abundant exposed sites for polysulfide capture but also accommodate a large amount of sulfur inside the pore structure. CNT was composited with silica to enhance the electronic conductivity of the interlayer, which is beneficial for fast sulfur redox reaction kinetics and improved utilization of sulfur. Compared to the pristine and CNT-modified separator, the mesoporous silica/CNT composite-modified separator enables better cycling stability and rate performance. More importantly, it was demonstrated that separately incorporating sulfur into a cathode and interlayer enables better battery performance than locating all the sulfur in the cathode. At a total sulfur loading of 4 mg cm−2 (3 mg cm−2 sulfur on the cathode and 1 mg cm−2 on the mesoporous silica/CNT interlayer), a high initial discharge capacity of 1410 mAh g−1 and a retained capacity of 952 mAh g−1 after 100 cycles were exhibited. This work provides important guidance for future design of functional interlayers for practical Li–S batteries. [ABSTRACT FROM AUTHOR]

Exploration of low‐dimensional Pb‐free halide perovskites with high stability and outstanding properties is still a pursuing target for developing integrated optoelectronic devices. Herein, comprehensive computational screening of a new class of two‐dimensional (2D) all‐inorganic Pb‐free A3B2X9 perovskites is performed based on the first‐principles calculations. The results indicate that the structural and electronic properties of 2D A3B2X9 structures strongly depend on the B‐X bonding interactions, which makes that their thermodynamic stability follows the trend of A3Bi2X9≈A3Sb2X9>A3In2X9>A3Ga2X9 and their interlayer interactions show a reversal trend. Owing to the lack of lone‐pair electron effect, A3In2X9 indicate direct bandgap characteristics and present the relatively smaller bandgaps and higher electron mobilities than A3Sb2X9 and A3Bi2X9. Benefit from optimal bandgaps (0.8–2.1 eV) and large absorption coefficients (104–105 cm−1) in the visible region, A3B2I9 (B = In, Sb, Bi) exhibit high power conversion efficiency up to 18.2%. Moreover, A3B2I9 (B = Sb, Bi) is verified as efficient photocatalysts for overall water splitting. The theoretical solar‐to‐hydrogen efficiency of Rb3Bi2I9 and Cs3Bi2I9 are >16%. This work suggests huge potential of 2D A3B2X9 perovskites for photovoltaic and photocatalytic applications. [ABSTRACT FROM AUTHOR]

Simple Summary: Polyphenol compounds are important physiological activity materials that resist corrosion and oxidation, can be maintained in a state of freshness, and can be used safely, among other advantages. In China, the most important cereal crop is sorghum, which is an important raw material for brewing. However, sorghum stalks are usually considered to have no value and are thrown away or burned, resulting in environmental pollution and the possible waste of a usable resource. Notably, the sorghum stalk contains an abundance of polyphenols that exhibit great development potential as unconventional resources. However, studies on sorghum stalks with respect to their polyphenol compounds and their effects on in vitro rumen fermentation in goats have been relatively rare to date. Accordingly, in the present study, six types of sorghum (Sorghum bicolor L. Moench) varieties used for brewing traditional Chinese liquor were selected, and we compared their stalks in terms of their chemical composition, polyphenol compounds, antioxidant activity, and effects on in vitro rumen fermentation in goats. Our findings provide new details regarding the use of this unconventional feed for goats, as well as theories for developing this kind of resource for use as ruminant feed. The aim of the study was to examine the differences in the chemical composition, polyphenol compounds, antioxidant activity, and in vitro rumen fermentation among six varieties of sorghum stalks. The results show that maoliangnuo 1 (M1) contained a higher (p < 0.05) level of dry matter, and jinzhong 405 (J4) contained a higher (p < 0.05) level of crude protein content. The concentrations of neutral detergent fiber, acid detergent fiber, and cellulose were significantly higher (p < 0.05) in stalk jinliangnuo (JN). The levels of chlorogenic acid, homoorientin, isovitexin, vitexin, rhoifolin, genistin, quercetin, apigenin, aloe emodin, emodin, and total polyphenols were all significantly (p < 0.05) higher in maohongnuo 6 (M6) than in the other stalks. Moreover, stalk M6 contained higher (p < 0.05) levels of total antioxidant capacity (TAC), glutathione peroxidase (GPX), catalase (CAT), and 2,2-diphenyl-1-picrylhydrazyl (DPPH) free-radical scavenging capacity. There were significant (p < 0.05) positive correlations between total polyphenols and TAC, superoxide dismutase, GPX, CAT, and DPPH free-radical scavenging capacity. The total gas production was significantly (p < 0.05) influenced by the sorghum stalk variety and incubation time. Stalk J4 displayed higher values for the (p < 0.05) immediately soluble fraction and the potential extent of gas production, while stalk M6 exhibited a significantly lower (p < 0.05) insoluble fraction level. Furthermore, stalk M6 exhibited a significantly higher level of (p < 0.05) ruminal fluid propionic acid, but its level of butyric acid and its ratio of acetic acid to propionic acid were both significantly lower (p < 0.05). Taken together, the results reported in this paper indicate that the chemical composition, polyphenol compounds, antioxidant activity, and in vitro rumen fermentation all vary greatly among different varieties of sorghum stalks. [ABSTRACT FROM AUTHOR]

The teaching mode of flipped classroom and micro class has gradually entered the daily teaching of College English classes. The new teaching concept and teaching mode not only promote the reform of the teaching mode in College English course, but also improve the teaching quality of College English course. This paper makes a rational distribution of teachers’ tasks and students’ tasks through the integration of "network model" and "classroom model", and designs the interactive turnover mode in College English teaching practice, which can promote the application of Information Science Technology in College English teaching.

InxGa1−xN nanowires (NWs) have attracted much interest as promising photocatalysts. In this article, InxGa1−xN nanowires were grown on an n-type Si (111) substrate by a Ni-catalyzed chemical vapor deposition (CVD) method. The preferred growth direction of the InxGa1−xN NWs may be tuned through the position of metallic sources (gallium acetylacetonate and indium acetylacetonate) by affecting the composition of the Ni-based droplets. The metallic precursors at a higher temperature position led to straight and coarse NWs (A-NWs) with an InxGa1−xN/GaN core/shell structure, which grew preferentially along the m-direction. In contrast, the metallic precursors at lower temperature positions resulted in curved and fine InxGa1−xN NWs (B-NWs) mainly along semipolar directions. The A-NWs/Si electrode exhibited a higher photocurrent but the B-NWs/Si electrode showed a better photocatalytic performance in terms of H2 evolution and CO2 reduction upon irradiation. The different performances were attributed to the high density of basal stacking faults (BSFs), which can give rise to anisotropic transport of photogenerated electrons in NWs. The respective growth mechanism was analysed for the A- and B-NWs and a novel strategy was proposed to engineer the growth direction and BSFs in the InxGa1−xN NWs. [ABSTRACT FROM AUTHOR]

Two-dimensional (2D) ferroelectric semiconductors, such as α-In 2 Se 3 with switchable spontaneous polarization and superior optoelectronic properties, exhibit large potential for functional device applications. The electric transport properties and device performance of 2D α-In 2 Se 3 are strongly sensitive to the ferroelectric domain structures and polarization textures, but they are rarely explored at the atomic scale. Herein, by a combination of first-principles calculations and a developed domain switching theory, we report the domain nucleation kinetics and polarization-texture dependent electronic properties in α-In 2 Se 3 ferroelectrics. Our calculated results reveal that the reversed domains characterized by armchair boundaries tend to form triangular or stripped shape. The energy barrier for propagating domain boundaries is ∼1.42 eV and can be reduced by loading external electric field, which is responsible for driving the evolution of domain structures. Moreover, the domain switching leads to notable changes in the band gap and carrier spatial distribution of α-In 2 Se 3 monolayer, resulting in higher electric resistance of multi-polarization domain structures than that of single-polarization state. The domain structures of multilayer α-In 2 Se 3 follow a layer-by-layer switching mechanism, which causes the transition of electronic structures from self-doped p-n junctions to type-II semiconductor homojunctions. This study not only provides an in-depth insight into the domain switching mechanisms of α-In 2 Se 3 but also opens up the possibility to tailor their electronic and transport properties.

In this study, zinc-gallium oxynitrides with a Zn:Ga mole ratio of 1:1 [(GaN) 0.5 (ZnO) 0.5 ] were synthesized from a Zn/Ga/CO 3 layered double hydroxide (LDH) precursor. The microstructure and photoactivity of the (GaN) 0.5 (ZnO) 0.5 particles were tuned by adjusting the nitridation conditions of the LDH. It is revealed that the quantity of the LDH, or, equivalently, the partial pressure of the water during nitridation, plays a pivotal role in the defect structure of the obtained oxynitrides. A reduction in the quantity of the LDH precursor can effectively suppress the formation of defects including Ga(Zn)-O bonding, bulk anion vacancies, and surface-deposited Ga/O N ···V Ga complexes, leading to a better charge-separation efficiency for the photogenerated electron-hole pairs in the oxynitride. Furthermore, a suitable introduction of methane during nitridation would not only increase the crystallinity of the bulk materials but also enhance the density of the surface oxygen vacancy (V O ), which would raise the charge-injection efficiency by working as an electron trap and a reaction site to form O 2 •- . O 2 •- , as well as photogenerated holes, have been proven to be the dominant active species for the photodegradation of phenol. 25CH 4 -ZnGaNO, with the lowest density of bulk defects and the highest density of surface V O , exhibited the best photoactivity under visible-light irradiation for the photodegradation of Rhodamine B and phenol. The obtained surface-V O -rich (GaN) 0.5 (ZnO) 0.5 particles can be applied as a high-performance visible-light-driven photocatalyst in the photodegradation of organic pollutants.

In x Ga 1-x N nanowires (NWs) have drawn great attentions for their applications in optoelectronic and energy conversion devices. Compared to conventional substrates, metal substrates can offer In x Ga 1-x N NW devices with better thermal conductivity, electric conductivity, and mechanic flexibility. In this article, In x Ga 1-x N NWs were successfully grown on the surface of a tantalum (Ta) substrate via vapor-liquid-solid chemical vapor deposition (VLS-CVD), as characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), scanning and transmission electron microscope (STEM), and photoluminescence spectroscopy (PL). It was found that the surface pretreatment of Ta and the composition of metallic catalysts played important roles in the formation of NWs. A dimpled nitrided Ta surface combined with a catalyst of nickle is suitable for VLS-CVD growth of the NWs. The obtained In x Ga 1-x N NWs grew along the [1100] direction with the presence of basal stacking faults and an enriched indium composition of ~3 at.%. The successful VLS-CVD preparation of In x Ga 1-x N nanowires on Ta substrates could pave the way for the large-scale manufacture of optoelectronic devices in a more cost-effective way.