Blast furnace slag is a type of bulk solid waste generated by the iron and steel industry. The high value-added utilization of blast furnace slag has been the focus of research in the relevant industries, which is of great significance to the green development of the steel industry. This work focuses on blast furnace slag and reviews the progress of its use as a photocatalytic material for wastewater treatment in the last five years. Firstly, we introduce the basic information of blast furnace slag, such as the formation and mineral composition of blast furnace slag, the feasibility of using it as a photocatalytic material, the current situation of comprehensive utilization at home and abroad, and the problems in comprehensive utilization. Secondly, the current status of photocatalytic technology is briefly explained, covering its mechanism of action, performance improvement methods and development trends. Then, the progress of research on blast furnace slag as a photocatalytic material for wastewater purification is described. The existing literature on the factors affecting its photocatalytic efficiency and ways to improve it are discussed. Finally, the treatment and application of blast furnace slag-based photocatalytic materials are summarized, and its sustainable resource utilization is also prospected.

MXene as a novel two-dimensional transition metal carbides, nitrides or carbonitrides has the excellent metal conductivity, high carrier mobility, and surface-terminated groups regulated band structure. It can be thus used as a cocatalyst in photocatalytic material systems to improve the photocatalytic properties. This review represented recent research progress on the controllable construction of MXene-based composites with zero-dimensional, one-dimensional, two-dimensional, and three-dimensional semiconductor photocatalytic materials and its applications in the photocatalytic fields (i.e., pollutant removal, hydrogen production, CO₂ reduction, and nitrogen fixation). Also, the construction methods and photocatalytic enhancement mechanisms of two-dimensional MXene-based composite photocatalysts were given. In addition, the future research directions of MXene-based composite photocatalysts were also prospected.

Nearly zero thermal expansion (NZTE) materials have a high dimensional stability with a less possibility producing thermal stress under variable-temperature environment. Therefore, they can be used in aerospace, microelectronics, optics, precision devices and other fields. Mn-based antiperovskite compounds Mn₃AX (A=metal or semiconductor element, X=N or C) have attracted recent attention due to their negative or nearly zero thermal expansion (NTE/NZTE) properties within a wide temperature range, isotropy and easy regulation. Mn₃AX compounds exhibit rich magnetic structures, and their NTE/NZTE properties are closely related to the magnetic phase transitions and intense lattice-spin correlation. The magnetic structure and magnetic phase transition can be changed via optimizing the composition, thus effectively regulating the thermal expansion behavior and obtaining other functional properties. The existing methods to obtain the wide temperature range NTE/NZTE properties mainly include the broadening of the NTE behavior in the magnetic phase transition temperature range, regulation of specific magnetic phases that critically affect negative/zero thermal expansion properties, and multi-phase composition of the materials with different thermal expansion coefficients. This review represented the experimental and theoretical studies on the regulation of abnormal thermal expansion behavior of Mn₃AX antiperovskite compounds in recent years. The effective regulation and in-depth analysis of the abnormal NTE/ZTE properties of Mn-based antiperovskite compounds can reveal the physical origin of the anomaly in thermal expansion, which can greatly promote the application of these materials. This review also summarized recent research progress on the regulation strategy and mechanism of the NTE/ZTE properties of Mn-based antiperovskite, and prospected the future direction in this field.

With the enhancement of people's awareness of environmental protection, environmentally friendly polyvinyl chloride (PVC) plastic additives are constantly promoted, and the use of natural mineral vermidemite to replace non-environmentally friendly PVC plastic additives has become a new trend in the industry. A vermiculite sheet suspension was obtained by a liquid high-speed shear/grading centrifugal method, and the vermiculite nanosheet/polyvinyl chloride (PVC) composite plastic was prepared via solvent substitution. The influence of the content of vermiculite nanosheet on the ultraviolet, thermal conductivity, thermal stability and flame-retardant performance, tensile properties was investigated. The results show that the sizes of vermiculite are 150 nm-1.1 μm, and the original structure of vermiculite preserves. When the content of vermiculite nanosheet is 15% (in mass), the tensile strength of vermiculite nanosheet/PVC composite plastic is increased by 50.8%, the limit oxygen index value is increased by 7.3%, the thermal conductivity is decreased by 17.8%, and the aging heat stability time is increased by 140 min, and the dehydrothermal degradation time is increased by 24 min. This composite plastic has superior thermal stability and ultraviolet resistance. Adding vermiculite nanosheet into PVC can improve the properties of composite plastic, which has a practical significance in the preparation of high-performance PVC product.

As an energy storage device, supercapacitors are practically used in many fields due to their high power density and long service life. Among the components of supercapacitors, electrode materials play a key role in the performance of the device, it is thus of great significance to prepare electrode materials with superior electrochemical performance. NiCo₂S₄ was prepared by a hydrothermal method using nickel acetate and cobalt acetate as raw materials, glutathione as a morphology control agent and a sulfur source. The effect of hydrothermal reaction time on the microstructure, morphology and electrochemical performance of NiCo₂S₄ was investigated. The results show that the NiCo₂S₄ material prepared under the action of glutathione has a yolk-shell structure. The specific capacitance is 1 552.7 F/g when the current density is 0.5 A/g, and the specific capacitance can be maintained at 61.3% at 10 A/g. After 2 000 cycles, the specific capacitance retention of the material can be maintained at 79.3%. A supercapacitor can be assembled with NiCo₂S₄ and activated carbon as positive and negative electrodes, respectively. This hybrid supercapacitor can provide 33.9 W·h/kg energy density when the power density is 800 W/kg. After 2 000 charge and discharge cycles, the specific capacitance retention rate is 89%.

Polysilicate aluminum chloride (PASC) flocculant was prepared with a coal gangue for the resource utilization of coal gangue. The effects of alkali cement ratio, roasting temperature, acid dosage, acid leaching temperature, liquid to solid ratio and acid leaching time on the performance of PASC were investigated. The physicochemical properties and microstructure of PASC were analyzed and the flocculation mechanism of PASC was discussed. The results show that the turbidity removal rate of PASC to coal slime water can reach 99.08% under the optimum conditions (i.e., alkali cement ratio of 0.9, roasting temperature of 900 ℃, acid dosage of 1.75 g/g, acid leaching temperature of 49 ℃, liquid to solid ratio of 8.9, and acid leaching time of 2.8 h). Since PASC is an amorphous polymer formed by the complexation of polysilicic acid, aluminum ions and hydroxyl groups, it has a rich spatial network structure and its flocculation mechanism includes adsorption bridging, trapping and sweeping, and charge neutralization.

Since the specific capacity of silicon monoxide anode material (SiO_x) has nearly four times greater than that of graphite, it is thus considered as the most promising next-generation anode material for full commercialization of Li-ion batteries. However, the problem of low initial Coulomb efficiency (ICE) has long plagued the application of SiO_x. Pre-lithiation can increase the ICE of SiO_x and improve the energy density of Li-ion battery systems, paving an effective way for the full-scale application of SiO_x. This review represented recent development and application on SiO_x anode pre-lithiation. The typical schemes and the corresponding effects were described, and the reaction mechanisms, challenges, and potential solutions were given. In addition, the future development on pre-lithiation technology was also prospected.

Aqueous Zn iodine battery (AZIDB) is recognized as one of the most promising energy storage devices in the future electric power storage area due to its high theoretical specific capacity, superior energy density, good rate capability, abundant and low-cost of raw materials and high safety. However, the shuttle effect of polyiodide seriously increases the self-discharge current, decreases the Coulombic efficiency and shortens the cycle life of AZIDB, further limiting the large-scale application. In this review, the configuration of AZIDB, the corresponding energy storage mechanism and the reasons of shuttle effect were represented. The suppression strategies of shuttle effect in AZIDB from cathode, electrolyte and separator aspects were described. In addition, we summarized the current problems and shared thoughts on the future research development in AZIDBs to provide a reference for promoting the industrialization of AZIDBs.

In the field of catalyst support and adsorption, mesoporous petal-like MgAl₂O₄ has attracted much attention because of their large surface area, abundant and accessible catalytic sites and not easy to aggregate. Mesoporous petal-like MgAl₂O₄ was prepared by a molten salt assisted non-hydrolytic sol-gel method with aluminum wire as aluminum source, magnesium powder as magnesium source, absolute ethyl alcohol as a solvent and Na₂MoO₄ as a molten salt, respectively. The effects of heat treatment temperature and soaking time on the phase composition and morphology of petal-like MgAl₂O₄ were investigated by X-ray diffraction and field emission scanning electron microscopy. The microstructure of the petal-like MgAl₂O₄ was determined by transmission electron microscopy (TEM), and the specific surface area and pore volume were measured by N₂ adsorption-desorption analysis. The results show that heat treatment temperature and soaking time both have an influence on the morphology. MgAl₂O₄ prepared has a petal-like morphology with a length of 140-160 nm when the heat treatment temperature and time are 900 ℃ and 8 h. The specific surface area of the prepared MgAl₂O₄ is 76 m²/g. Based on the results by TEM and N₂ adsorption-desorption analysis, the petal-like MgAl₂O₄ exhibits a mesoporous structure. This work paves a promising approach to prepare mesoporous petal-like MgAl₂O₄.

Ag surface plasmon resonance promoted step-scheme (S-scheme) SnNb₂O₆/Ag₃PO₄ heterojunctions were constructed via simple chemical deposition and precipitation. The samples were characterized by X-ray diffractometer, field-emission scanning electron microscope, high resolution transmission electron microscope, X-ray photoelectron spectrometer, UV-Vis diffuse reflectance spectrometer and photoluminescence spectrometer. The photocatalytic activities of SnNb₂O₆, Ag₃PO₄ and SnNb₂O₆/Ag₃PO₄ composites can be determined via degradation experiments. The results show that the SnNb₂O₆/Ag₃PO₄ composite possesses an optimum degradation performance in the photocatalytic degradation of methylene blue. Besides, the pseudo-first-order rate constant (K_app) of SnNb₂O₆/Ag₃PO₄ is 0.313 min^-1, which is 13.1 times and 4.8 times greater than that of SnNb₂O₆ and Ag₃PO₄, respectively. Also, Ag surface plasmon resonance-promoted SnNb₂O₆/Ag₃PO₄ S-scheme heterojunction can accelerate the separation of electron-hole pairs, thereby enhancing the redox reaction capability of the whole system.