MgH₂ has become a hot spot in the research of hydrogen storage materials, due to its high theoretical hydrogen storage capacity. However, the poor kinetics and thermodynamic properties of hydrogen absorption and desorption seriously hinder the development of this material. Ti-based materials can lead to good effects in terms of reducing the temperature of MgH₂ in hydrogen absorption and desorption. MXene is a novel two-dimensional transition metal carbide or carbonitride similar in structure to graphene. Ti₃C₂ is one of the earliest and most widely used MXenes. Single-layer Ti₃C₂ can only exist in solution; in comparison, multilayer Ti₃C₂ (ML-Ti₃C₂) also exists as a solid powder. Thus, ML-Ti₃C₂ can be easily composited with MgH₂. The MgH₂+ML-Ti₃C₂ composite hydrogen storage system was successfully synthesized by ball milling. The experimental results show that the initial desorption temperature of MgH₂-6 wt.% ML-Ti₃C₂ is reduced to 142 °C with a capacity of 6.56 wt.%. The E_a of hydrogen desorption in the MgH₂-6 wt.% ML-Ti₃C₂ hydrogen storage system is approximately 99 kJ/mol, which is 35.3% lower than that of pristine MgH₂. The enhancement of kinetics in hydrogen absorption and desorption by ML-Ti₃C₂ can be attributed to two synergistic effects: one is that Ti facilitates the easier dissociation or recombination of hydrogen molecules, while the other is that electron transfer generated by multivalent Ti promotes the easier conversion of hydrogen. These findings help to guide the hydrogen storage properties of metal hydrides doped with MXene.

Borate esters have been emerging as a good candidate in green additives for the increasing needs of environmental protection. A versatile boron–nitrogen-modified castor oil additive (abbreviated as BNC) was prepared. The thermal stability and the oxidation stability of BNC were evaluated. The oil solubility, dispersion stability, lubricity, and biodegradability of BNC in both rapeseed oil and 400SN mineral oil were investigated, respectively. The morphology and tribo-chemical characteristics of the worn surfaces were examined by scanning electron microscope and energy dispersive spectrometer to reveal the possible lubricating mechanisms. The results indicated that the BNC additive had good thermal stability and anti-oxidation ability. The oil solubility and dispersivity of BNC in rapeseed oil is better than that in 400SN mineral oil. The BNC additive could effectively improve the anti-wear and friction-reducing properties of rapeseed oil and 400SN mineral oil. The surface analysis indicated that elemental boron, nitrogen, and oxygen are involved in the lubrication films, and it was deduced that the physical adsorption films, chemical adsorption films, chemical reaction films, and permeable layers work together to reduced friction and wear. Moreover, the BNC could improve the biodegradability of both rapeseed oil and mineral oil, which was attributed to the promoted growth and quantity of microbes by elemental nitrogen involved in BNC. The synthesized BNC additive was demonstrated a potential ecofriendly and effective lubricant additive in industrial applications.

The thermal decomposition characteristics of methyl linoleate (ML) under nitrogen and oxygen atmospheres were investigated, using a thermogravimetric analyzer at a heating rate of 10 °C/min from room temperature to 600 °C. Furthermore, the pyrolytic and kinetic characteristics of ML at different heating rates were studied. The results showed that the thermal decomposition characteristics of ML under nitrogen and oxygen atmospheres were macroscopically similar, although ML exhibited relatively lower thermal stability under an oxygen atmosphere than under a nitrogen atmosphere. The initial decomposition temperature, the maximum weight loss temperature, the peak decomposition temperature, and the rate of maximum weight loss of ML under an oxygen atmosphere were much lower than those under a nitrogen atmosphere and increased with increasing heating rates under either oxygen or nitrogen atmosphere. In addition, the kinetic characteristics of thermal decomposition of ML were elucidated based on the experimental results and by the multiple linear regression method. The activation energy, pre-exponential factor, reaction order, and the kinetic equation for thermal decomposition of ML were obtained. The comparison of experimental and calculated data and the analysis of statistical errors of pyrolysis ratios demonstrated that the kinetic model was reliable for pyrolysis of ML with relative errors of about 1 %. Finally, the kinetic compensation effect between the pre-exponential factors and the activation energy in the pyrolysis of ML was also confirmed.

The unique properties of two-dimensional (2D) materials make them increasingly attractive in various fields, especially for energy harvesting, conversion, or storage. Simultaneously, numerous synthetic methods have been rapidly developed. Recently, topochemical strategies were demonstrated, and they show tremendous promising potential for synthesizing 2D materials due to their simplicity, scalability, and high efficiency. Considering the suitability of material structures and their synthesis methods, as well as the relationship between material properties and applications, it is necessary for researchers to comprehensively review and determine the prospects of 2D materials based on topological chemical synthesis methods and their related applications. Therefore, in this review, we systematically summarize and analyze the representative topochemical strategies for synthesizing 2D materials, including salt-templating methods for non-layered 2D materials, molten Lewis acid etching strategy for novel MXenes, and the chalcogen vapors etching and substituting strategy for phase-controlled 2D materials and so on, with the application of these 2D materials in energy-related fields including batteries, supercapacitors, and electrocatalysis. At the end of the paper, the corresponding perspective was also illustrated, and we expect that this could provide a reference for the future research in the field.