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An Al-based energetic micro-unit Al@PFPE@AP fuel powder with the oxidant AP coated on the surface of fluoride-modified Al powder was designed and prepared by the component composite technique to address the two major problems of incomplete combustion and component polarization of Al powder in solid propellants. The morphology, particle size, combustion properties and combustion products of the micro-unit powder were analyzed by scanning electron microscopy, laser particle size measurement, oxygen bomb calorimetry, inductively coupled plasma emission spectrometry and X-ray diffraction. The results show that the energetic microunits Al@PFPE@AP present a more obvious core-shell structure with uniform particle size, and when the addition amount of PFPE is 5%, the combustion heat value of Al@5%PFPE@AP is increased by 63.86%, the particle size of combustion products is decreased by 61.83%, and the active aluminum content of combustion products is decreased by more than 57% compared with the mechanically mixed AP+Al samples. Combustion mechanism analysis shows that PFPE can occur with Al powder pre-ignition reaction, increase the reaction activity of Al powder, and the surface of Al powder has a catalytic effect on the decomposition of AP, which reduces AP high temperature decomposition temperature and low temperature decomposition temperature were reduced by 12 ℃ and 10 ℃ respectively. The micro-unit structure has a significant contribution to the improvement of the combustion performance of the system and can substantially increase the energy performance of the important propellant components during combustion.

Black phosphorus (BP) has attracted rapidly growing attention for potential applications in next-generation flexible supercapacitors (FSCs) owing to its exceptional properties such as large specific surface area, unique lamellar structure, and excellent flexibility. However, one intractable problem is that BP-based FSCs suffer from poor cycling stability due to the high reactivity toward O2 and inherent structural instability of BP. Herein, a "chemical and spatial hierarchical-locking" strategy is developed to successfully construct ultra-stable BP hybrids. Three-dimensional encapsulation of a covalently bonded BP/conductive carbon nitride (BP/c-CN) domain with electrolyte-infiltrated SCNT networks yields a spatial solid-electrolyte interphase that can effectively shield against O2, slowing down the degradation of BP. Besides, the solid-electrolyte interphase can shorten the transfer distance of electrolyte ions to the electrode, thus achieving rapid charge-transfer kinetics. Meanwhile, the covalent P–C bonds between BP and c-CN contribute to building a "robust skeleton", concurrently preventing the structural distortion of BP. Significantly, the BP/c-CN@SCNT-based FSC delivers a remarkable cycling ability with 100% capacitance retention after 50 000 cycles, less than 10% capacitive decay after 6 months under ambient conditions, and a high energy density of 15.1 mW h cm−3, making it promising for practical applications. This work provides a new insight for designing high-performance and stable BP-based electrodes for FSCs. [ABSTRACT FROM AUTHOR]

Enhancing the photocatalytic stability of Cu2O in the degradation of tetracycline is a great challenge in combating environmental water pollution because it is prone to deactivation by photocorrosion in aqueous environment. In this study, Cu2O/cellulose microfiber aerogel is synthesized through freeze‐drying, utilizing the self‐curling effect of cellulose and then calcined to produce Cu2O/C composite aerogel. The derived Cu2O/C composite aerogel features hollow carbon microfibers anchored with Cu2O nanocubes. Due to the curling structure and conductivity of the carbon microfibers, the photodegradation efficiency of the obtained Cu2O/C composite aerogel for tetracycline is drastically improved to 97.3% under 120 min of visible‐light irradiation, and remains a cycling photodegradation rate of 84.3% after 10 cycles. The Cu2O/C composite aerogel shows remarkable strategies for designing and constructing Cu2O‐based photocatalyst in the practical photodegradation of tetracycline under visible‐light exposure. [ABSTRACT FROM AUTHOR]

In the process of steam injection development of heavy oil, due to the serious heterogeneity and interference of steam channeling in the high-permeability layer, there is a lot of oily sludge in the produced liquid of oil wells, which is difficult to deal with. According to existing profile control technology and the related properties of oily sludge, a profile control system was developed by using oily sludge as the main agent and by adding other additives. At the same time, the properties of sludge, the matching relationship between the particle size of sludge and the formation of pore roar, the temperature resistance, the plugging ability, and other contents were studied. The agent featured an adjustable curing time (3 to 300 h) and resistance to pressures greater than 6 MPa and temperatures greater than 350 °C. After the agent was injected into the high-permeability steam channeling, the system was cemented with the formation rock and the sealing rate was more than 85%, without any damage to the low- and medium-permeability layers. According to the different characteristics of the production well and steam injection well, the construction technology was optimized, the oily sludge profile control technology suitable for heavy oil reservoirs was formed, and the field test was carried out. At present, more than 150 wells have been used in the field, with a cumulative oil increase of 10,756 tons. The technology not only solves the environmental pollution caused by oily sludge but also reduces the cost of thermal recovery of heavy oil, with great significance for improving the final recovery efficiency and commercial benefits of the oilfield. [ABSTRACT FROM AUTHOR]