Titanium dioxide (TiO₂) exhibits weak surface electron polarization and a poor response in the microwave region, resulting in its limited electromagnetic (EM) loss capability, which restricts its application in EM wave absorption. Recent research has revealed that the reduced phase of TiO₂, denoted as Ti_xO_2x-1 (1≤x≤10), possesses both metallic and semiconducting properties. This duality, coupled with its relatively high electrical conductivity, positions Ti_xO_2x-1 as a promising candidate for the next generation of EM wave absorbers. However, current investigations into Ti_xO_2x-1 absorbers primarily focus on the EM property modulation of black TiO₂ and its composites, while the influence of crystal structure, lattice defects, and band structure on the EM parameters and absorption performance of Ti_xO_2x-1 absorbers remains unclear. Consequently, there is a lack of a comprehensive Ti_xO_2x-1 absorber system both domestically and internationally. Based on the fundamental principles of EM wave absorption materials, this study discusses the crystal structure and formation mechanism of Ti_xO_2x-1 and defective TiO₂, as required by semiconductor metal oxides. The paper summarizes the high-efficiency EM wave absorption properties of TiO₂-derived Ti_xO_2x-1 absorbers with various texture designs, achieved through defect engineering and interface engineering. Focusing on the challenges of "poor absorbing performance" and "unclear absorbing mechanisms" in Ti_xO_2x-1 absorbers, this work aims to achieve optimal design of Ti_xO_2x-1 materials, enhance their absorbing capabilities, and establish an electromagnetic control mechanism for oxide-semiconductor absorbers. By employing methods such as defect regulation, compositional optimization, and interface design, multiple EM loss mechanisms including conductivity loss, dipole polarization, interface polarization, and coupling effects, are established and optimized. Accordingly, this approach improves the impedance matching and EM loss capabilities of Ti_xO_2x-1-based absorbers, ultimately resulting in absorbers with superior wave-absorbing performance. Finally, by integrating domestic and international research progress, this paper proposes a novel design strategy for Ti_xO_2x-1 absorbers, which holds significant implications for the future development and application of semiconductor metal oxide absorbers.

Prolonged exposure to hot weather and direct sunlight can lead to heat exhaustion and skin irritation, which reduces the productivity of outdoor workers and increases health risks. This study has developed a polylactic acid/boron nitride nanosheet composite fabric by electrospinning. Being selectively modified for hydrophilicity, the fabric has combined passive radiative cooling, thermal conductivity and directional sweat wicking to improve thermal comfort in outdoor environments. Compared to conventional cotton fabrics, the composite fibric exhibits excellent solar reflectance (96%) and infrared heat emissivity (93%), along with high thermal conductivity (0.38 W·m⁻¹·K⁻¹). In outdoor experiments, the composite fabric lowers skin temperature by 2.0 °C under direct sunlight during the day and by 3.8 °C at night relative to bare skin. The composite fabric features a directional perspiration function and an impressive sweat evaporation rate of 1.67 g·h⁻¹, which can efficiently transport sweat and heat to the fiber membrane surface to keep the skin dry and cool. This work should advance human thermal management strategies for high-temperature outdoor environments.

Tin-lead (Sn-Pb) alloyed perovskites with tunable bandgaps hold great potential for constructing highly efficient single-junction and tandem photovoltaic devices. However, the efficiency and stability of Sn-Pb perovskite solar cells (PSCs) are greatly hampered by severe nonradiative recombination due to the easy oxidation of Sn(II). In this work, we report the construction of mixed dimensional two-dimensional (2D) Dion–Jacobson (DJ) and three-dimensional (3D) perovskites to improve the efficiency and stability of Sn-Pb alloyed PSCs. Introducing a small amount of 1,4-butanediammonium diiodide as spacer cations of DJ perovskites into precursor, the prepared mixed dimensional Sn-Pb alloyed perovskites exhibit reduced trap-state density due to the passivation of 2D DJ perovskites. As a result, nonradiative charge recombination is greatly suppressed. The prepared Sn-Pb alloyed PSCs based on 2D-DJ/3D heterojunction deliver a power conversion efficiency of 19.02% with an impressive fill factor of 80%. As well, improved device stability is realized due to the presence of DJ perovskites which serves as a protection barrier against oxidation and water invasion.