Energy storage is becoming a critical issue due to the diminishing availability of fossil fuels and the intermittent nature of current renewable energy sources. As a result, thermal management (TM) and thermal energy systems have gained significant attention due to their crucial roles in various industries. Among the different TM materials, MXenes, a member of the transition metal carbide/nitride family, have emerged as a promising material due to their unique 2D nanostructure, changeable surface chemistry, high electrical/thermal conductivity, light absorptivity, and low infrared emissivity. This review outlines the synthesis methods of MXenes and their various features and applications in thermal management. These 2D materials exhibit outstanding optical and thermal properties, making them suitable for thermal energy generation and storage. The study also covers the potential applications of MXene in the desalination industry, hybrid photovoltaic thermal systems, solar energy storage, electronics, and other thermal management related industries. The findings suggest that MXene-based TM materials have remarkable features that significantly influence thermal energy storage and conversion and present opportunities for further research in efficiently using these materials.

Recently, there has been a shift towards renewable energy sources for electricity generation due to rapidly depleting non-renewable energy sources. Solar energy is generally the most promising renewable energy source to be harvested by concentrated solar power (CSP) and solar photovoltaic (PV) technologies. CSP technology can be further classified into a few categories, such as parabolic trough collector (PTC), solar power tower, linear Fresnel reflector, and solar parabolic dish. In contrast, solar PV can be further developed into concentrated photovoltaic and concentrated photovoltaic thermal (CPVT) systems. The modifications (e.g. optical and thermal modifications) done on PTC and parabolic trough based CPVT systems on enhancing system performance are discussed. Next, the economic analyses conducted for both systems are discussed to compare the economic feasibility of the technologies employed in different countries. The appropriate recycling and CE approaches applied for PTC and PV technologies are reviewed and classified based on the key material elements within this industry. Overall, this paper compares PTC and parabolic trough-based CPVT systems from the technical, economic, and environmental aspects to provide insight for the solar energy harvesting field researchers.

Recycling carbon fibre waste is crucial for sustainability in the composites industry. Herein, we report the fabrication of a heterostructure composite using recycled carbon fiber (RCF) and n-type bismuth telluride (n-Bi2Te3) for thermoelectric applications. In the present study, we have comprehensively investigated the effects of annealing temperature and time on the thermoelectric, structural, charge carrier transport, morphological, and thermal stability properties of annealed RCF/n-Bi2Te3 composites. The optimum annealing temperature and time were at 350°C and 2 hours, respectively, which yielded a maximum power factor of 7.83 µWK-2m-1. Annealing redistributed the bismuth and tellurium atomic percentage, decreased carrier concentration, improved carrier mobility, enhanced the crystallinity and increased the grain size of the bismuth telluride particles, subsequently improving the thermoelectric performance as well as the thermal stability of annealed RCF/n-Bi2Te3 composites. In addition, this study has explored the plausibility of a cross-plane configured Seebeck coefficient measurement utilizing recycled carbon fibre/n-type bismuth telluride heterostructure thermoelectric composite. Energy band diagram analysis indicated favorable heterojunction alignment between RCF and n-Bi2Te3, validating the viability of the thermoelectric composite in a cross-plane configuration. Our study provides a promising route for closing the recycling loop of carbon fiber waste and achieving sustainable thermoelectric materials.

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In this study, MoS2–hBN hybrid nanoparticles were synthesized using an advanced microwave platform for new nanolubricant formulations. The synthesized nanoparticles were characterized by field-emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, X-ray diffraction, and Raman spectroscopy. The hybrid nanoparticles were then introduced into a 20W40 diesel-based engine oil to produce a nanolubricant. The physical and chemical properties of the nanolubricant were investigated, including the viscosity index, stability, volatility, tribological properties, oxidation properties, and thermal conductivity. The results showed that the inclusion of 0.05 wt% MoS2–hBN hybrid nanoparticles in the oil significantly reduced the coefficient of friction and wear scar diameter by 68.48% and 35.54%, respectively. Moreover, it exhibited substantial oxidation and thermal conductivity improvement of 38.76% and 28.30%, respectively, at 100 °C. These findings demonstrate the potential of MoS2-hBN hybrid nanoparticles as an effective additive to enhance the properties of nanolubricant significantly. Furthermore, this study offers valuable insights into the underlying mechanisms responsible for the observed enhancements. The promising outcomes of this investigation contribute to the advancement of nanotechnology-based lubricants, showcasing their potential for improving engine efficiency and prolonging the lifespan of machinery.