This study systematically investigated the effect of gypsum, added after clinker firing during cement preparation, on the hydration behaviour and performance of belite calcium sulfoaluminate (BCSA) clinkers synthesised at a low temperature of 1150°C, with clinkers prepared at 1250°C evaluated for comparison. A series of analytical techniques including X-ray diffraction, thermogravimetric analysis, Fourier transform infrared spectroscopy and compressive strength tests were performed. The results showed that the addition of gypsum accelerated the early hydration of BCSA clinkers. Increasing gypsum content promoted the formation of ettringite while inhibiting the hydration of belite and the precipitation of monosulfate and strätlingite. Clinkers produced at 1150°C exhibited greater hydration reactivity of ye’elimite than those prepared at 1250°C. The increased consumption of aluminium hydroxide indicated greater belite dissolution in clinkers synthesised at lower temperature. BCSA clinkers gained strength rapidly at early ages from fast ye’elimite hydration, while later strength depended on belite hydration. Higher gypsum content increased early-age strength but reduced strength at later ages. Clinkers fired at 1150°C exhibited higher strength than those prepared at 1250°C. It is noteworthy that low-temperature firing offers significant benefits in performance and environmental sustainability for BCSA clinker production.

Silicon (Si) anodes exhibit exceptional theoretical specific capacity as prospective alternatives to conventional graphite in lithium-ion battery systems. Nevertheless, their commercial implementation faces critical impediments arising from substantial volumetric expansion during lithiation, interfacial mechanical degradation, and intrinsically limited ionic/electronic conductivity. Here we report a dual-shell Si anode architecture in which a conformal metallic tin (Sn) interconnection bridge is rationally engineered between a Si core and a metal--organic-framework-derived nitrogen-doped carbon shell. Unlike conventional Si/C or Si/Sn/C composites that suffer from interfacial delamination and non-uniform coatings, our work introduces a metallic Sn interconnection bridge formed via in-situ carbothermal reduction of a hydrothermally deposited SnO2 layer. This Sn bridge not only provides a continuous, ductile, and conductive interface but also enables a uniform and intact ZIF-8-derived carbon shell through preferential Zn2 + adsorption, which are rarely achieved in reported Si-Sn-C systems. The Sn bridge not only reinforces interfacial bonding and electrical connectivity but also acts as a dynamic stress-relief medium that synergistically couples with the outer carbon shell to accommodate large Si volume changes. The rationally integrated multi-component architecture collectively contributes to the electrode's structural integrity and electrochemical stability. The optimized anode architecture demonstrates a reversible specific capacity of 1618.9 mAh g-1 sustained over 400 cycles at a current density of 1 A g-1, while maintaining 993.1 mAh g-1 under elevated rate conditions of 5 A g-1. Such electrochemical performance substantially surpasses that of conventional silicon-carbon composite analogues. This work establishes a generalizable interfacial-bridge design paradigm that integrates mechanical buffering, electronic transport, and electrochemical activity within a single metallic interlayer, thereby illuminating rational design strategies toward structurally robust, kinetically favorable silicon-based anode architectures for next-generation high-energy-density lithium-ion storage systems.

For the epoxidation of methyl oleate (MO), slow chemical reaction rate resulted from poor mass transfer remains a tough problem. Herein, we demonstrate a series of efficient 2D channel catalysts with accessible open transport channels, which provides an idea strategy for boosting epoxidation of MO and shortening its reaction time. 2D channel catalysts (2D-CSx-NH2-HPA) are fabricated by immobilizing heteropoly acid (HPA) on aminopropylfunctionalized 2D channel silica (2D-CSx-NH2), in which HPA is highly dispersed. These catalysts are applied to the epoxidation of MO, and the results show that the epoxidation performance of 2D channel catalysts for MO is related to its particle size and HPA types. As expected, the 2D-CS3.5-NH2-HPW with a length of 300 nm and an equatorial diameter of 150 nm exhibits outstanding catalytic activity (XMO = 91.68%) and epoxide selectivity (SEMO = 90.03%) with only 4 hours, which is much faster than that of majority of epoxidation catalysts reported so far. The excellent catalytic activity of 2D channel catalyst benefits from the appropriate pore width and particle size, which play an important role in exchanging substrates and dispersing active components. This study uses 2D channel catalyst to effectively shorten the reaction time of MO epoxidation, which paves a new avenue to develop other 2D channel materials for novel catalytic applications.

Interface engineering can improve the charge separation efficiency and inhibit photocorrosion is an emerging direction of developing more efficient and cost-effective photocatalytic systems. Herein, we report the sulfur-confined intimate CdS intergrown Cd (CdS/Cd) Ohmic junction (peanut-chocolate-ball like) for high-efficient H2 production with superior anti-photocorrosion ability, which was fabricated from in-situ photoreduction of CdS intergrown Cd2SO4(OH)2 (CdS/Cd2SO4(OH)2) prepared through a facile space-controlled-solvothermal method. The ratios of CdS/Cd can be effectively controlled by tunning that of CdS/Cd2SO4(OH)2 which were prepared by adjusting the volume of reaction liquid and the remaining space of the reactor. Experiments investigations and density functional theory (DFT) calculations reveal that the CdS intergrown Cd Ohmic junction interfaces (with appropriate content Cd intergrown on CdS (19.54 wt%)) are beneficial in facilitating the transfer of photogenerated electrons by constructing an interfacial electric field and forming sulfur-confined structures for preventing the positive holes (h+) oxi-dize the CdS. This contributes to a high photocatalytic H2 production activity of 95.40 lmol h-1 (about 32.3 times higher than bare CdS) and possesses outstanding photocatalytic stability over 205 h, much longer than most CdS-based photocatalysts previously reported. The interface engineering design inspired by the structure of peanut-chocolate-ball can greatly promote the future development of cat-alytic systems for wider application. (c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Despite the widespread application of ultrasmall nanosilica, solving its aggregation problem during the preparation process remains a challenge. In this paper, ultrasmall nanosilica with a controllable size and aggregates were prepared through the water-in-oil (W/O) emulsion method by using polyisobutylene succinic anhydride-type polymeric surfactants (PIBSA-X) as an isolating agent. PIBSA-X polymeric surfactants with different hydrophilic groups were prepared using industrial-grade PIBSA, which can form stable W/O-type emulsions well. Subsequently, the W/O-type emulsion droplets were used as reactors and tetraethyl orthosilicate was hydrolyzed under ammonia alkaline conditions to synthesize ultrasmall nanosilica (10 nm). Furthermore, the morphological evolution of nanosilica aggregates can be tuned by varying the oil/water ratio, which controls the emulsion droplets. A possible mechanism is proposed to explain why the emulsion method approach affords nanosilica aggregates with various morphologies and pellet size in water-in-oil (W/O-type) emulsion droplets. This study provides a precise and simple synthetic method for the development of ultrasmall nanosilica, which has good potential to be industrialized.

Exploration of efficient and earth-abundant catalysts is critical to developing hydrogen energy through electrochemical overall water splitting. In this work, highly porous three-dimensional binder-free amorphous structure NiFeO/NiMo nanospheres are synthesized on Ni foam (NF) by simple and cost-effective two-step hydrothermal and electrodeposition processes, respectively. The first findings show that the porous NiFeO/NiMoO/NF electrode has good long-term stability for the hydrogen evolution reaction (HER) in alkaline water electrolysis and better catalytic activity (requires an overpotential of 46 mV to drive current density (j) of 10 mA cm-2).The excellent HER performance and reasonable stability of the amorphous NiFeO/ NiMoO/NF electrocatalyst can be caused by the impact of intermediate coating (NiMoO) as a binder to the fabrication of the final catalyst, which enables a synergistic effect of metallic Ni, Fe, and Mo for efficient HER. Designing a multimetallic alloy represents a promising new route to developing efficient, low-cost noble-metal-free catalysts and their applications in the rising hydrogen revolution.(c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Design and synthesis of hierarchical self-assembly 2D channel silica (2D-CS) with mesoscopicshape control and developing of their application in catalysts have remained a challenge. Herein, we fabricated a series of 2D-CSx materials through hierarchical self-assembly of curved lamellar micelles and their derivative 2D channel catalysts (2D-CSx-NH2-HPW) by grafting amino group and immobilizing phosphotungstic acid, which exhibit highly effective oxidative-adsorptive desulfurization (OADS) performance due to their accessible open transport channels. A novel theory of curved lamellar micelles stacking likes the wrinkled papers was proposed to explain the hierarchical self-assembly mechanism of the 2D-CS, which follows the natural rule “short-range order, long-range disorder”. Systematic characterizations and experiments indicated that the size and specific surface area of 2D channel catalysts jointly determine their OADS performance. Most importantly, the 2D channel catalysts catalyst shows the highest removal efficiency of DBT compared with 0D and 1D materials, which was ascribed to its accessible open transport channels contributed to molecular diffusions. The optimal 2D channel catalysts (2D-CS4-NH2-HPW) exhibited excellent desulfurization performance without using an extraction, and the removal efficiency of DBT reached 99.72.% in 5 min at 60 ᵒC, much faster than previously reported mesoporous catalysts supported heteropoly acid. In addition, the OADS activity of typical sulfur compounds by using 2D-CSx-NH2-HPW catalyst was investigated and the sulfur removal efficiency decreases orderly as follows: DBT > 4,6-DMDBT > BT> n-DDM. The 2D channel catalyst also exhibits excellent recycling capability without significant loss of OADS activity after 10 cycles of reactions. This work provides a strategy for constructing 2D channel catalysts for efficient desulfurization, paving a new direction of 2D channel carries toward catalytic applications.

In this work, novel silver nanoparticles supported on amino-functionalized peeled-watermelon-like silica-coated magnetic catalysts (Fe3O4@SiO2-NH2-Ag) were successfully synthesized for the catalytic reduction of 4-nitrophenol (4-NP) in wastewater. The Fe3O4 nanoparticles were further coated with silica forming a structure similar to peeled watermelon to improve the stability of magnetic Fe3O4 and inhibit their aggregation. Furthermore, surface modification of Fe3O4@SiO2 particles with amino groups was used for the immobilization of silver nanoparticles. As a result, the Fe3O4@SiO2-NH2-Ag (10%) exhibits excellent catalytic activity to reduce 4-NP, which obtained the first-best reaction rate constant of 0.026 s(-1). Besides, the Fe3O4@SiO2-NH2-Ag could be easily recovered under an external magnetic field and was reused for 25 catalytic cycles without a significant decline in catalytic activity. The related catalytic mechanism of the reaction was discussed. Overall, the excellent magnetic recyclable nature and immortal catalytic activity make Fe3O4@SiO2-NH2-Ag a very promising material for practical use.

Tribocorrosion tests were conducted on Ti6Al4V against alumina in phosphate buffered saline solution under normal loads of 3?30 N (corresponding to the maximum Hertzian contact pressures of 816?1758 MPa) using a ball-on-disk tribometer. Nano-hardness measurements revealed the formation of work-hardened layers on the pure wear and tribocorrosion surfaces. As the normal load increased from 15 to 30 N during the pure wear, the surface hardness was increased by about 100％. However, a lower generation of wear debris resulted in a lower wear rate under a normal load of 30 N. The presence of corrosion caused an increase in the wear rates by 28％?245％ under various normal loads. The corrosion current density acquired from polarization curves was increased by three orders of magnitude and the open circuit potential (OCP) shifted to more negative potentials during tribocorrosion compared with the stagnant condition. The successive formation and removal of tribofilms, which consisted of oxygen and phosphorous compounds, resulted in peaks in the OCP trend and lower fluctuations in coefficient of friction under normal loads higher than 3 N.

The lithium-ion battery (LIB) is an efficient electrochemical energy storage device with high voltage, long life, good safety, etc. Silicon has a high theoretical specific capacity (4200 mA h g−1), due to which it is considered a promising anode material for next-generation LIBs. However, the huge volume change (400%) of the Si material during the lithiation/delithiation processes destroys its structure, which greatly reduces the initial coulombic efficiency, cycle stability and rate performance of the battery. Accordingly, constructing nanostructured Si, particularly silicon nanowires (SiNWs), can help to address the above issues. Additionally, it is important to further improve the electrochemical performance by incorporating some additives in SiNW-based electrodes. Therefore, this review focuses primarily on SiNW-based materials as anodes for LIBs from a material-based perspective. Various materials incorporated into SiNW-based anodes through doping or compositing are reported. The electrochemical effects of diverse additives, including carbon materials, metals, metal oxides, polymers, Si-based materials and other special substances, are comprehensively reviewed.

利用大气等离子喷涂在C/SiC复合材料表面制备BSAS涂层,并研究涂层的高温抗氧化性能.结果表明:包裹有BSAS涂层的复合材料在1 400℃下抗氧化性能良好,120 h后,样品失重率仅为复合材料自身失重率的1/7.1 400℃下热循环300 h后涂层剥落失效,同时发现BSAS涂层由六方相生成单斜相.

Based on the corrosion issue of cooling water system containing copper ,the corrosion inhibition properties and protection mechanism of inhibition on copper and stainless steel were studied by performing the electrochemical test ,immersion test and dynamic water simulation test .The results show that corrosion inhibitors have excellent corrosion inhibition efficiency on copper in the condition of either pure water or harsh water . The optimum inhibitor is the compound consisting of TTA and sodium orthophosphate .At the same time , the corrosion inhibitor elevates the breakdown potential of stainless steel and contributes to the enhancement of corrosion resistance .

The effects of temperature and humidity on the breakage propensity of two organic materials, Aspirin and sucrose, were investigated. The breakage propensities of both materials were found to be insensitive to humidity at ambient temperature; however they both showed a change in their impact breakage extent as a function of temperature, with Aspirin showing a more pronounced trend as compared to sucrose. Using the breakage data as a function of temperature, a lumped parameter, representing hardness, H, and fracture toughness and having the form H/Kc2 according to the model of Ghadiri and Zhang [1], was evaluated as a function of temperature. The value of this parameter also showed an increase with temperature, indicating that the fracture toughness of Aspirin should decrease with an increase in temperature, considering the functional form of the parameter. In addition, its breakage propensity as a function of temperature was found to be well described by the Arrhenius equation from which the activation energy, − 19.04 J/mol can be explained as equivalent to the energy required to overcome plastic deformation and initiate fracture.

Abstract:The effect of tempering temperature and tempering time on the mechanical properties of 40Cr3MoV steel has been studied. Comparing to tempering time, tempering temperature has stronger effect on the mechanical properties. Below 550 ℃, the mechanical properties change slightly with the increase of temperature; above 580 ℃, the strength drops and the toughness increases rapidly with the increase of temperature.