This study uses discarded tree leaves to produce biomass porous carbon nanosheets (PCNS) via carbonization and pore-forming processes, then modifies them with carboxymethyl chitosan (CMCS) and 8-hydroxyquinoline (8-HQ).

Graphene and its derivatives are widely used in various fields due to their unique two-dimensional lamellar structure. This study aims to synthesize ultra-large graphene oxide (GO) sheets from natural flake graphite and investigate the factors influencing their size. Using a two-intercalation method based on the modified Hummers' method, we address the challenge of intercalating large-diameter graphene oxide by employing a secondary intercalation technique. Three different approaches were explored to control the size of the produced GO sheets. The results revealed that the completeness of the expansion graphite structure after initial intercalation significantly influenced the final GO sheet size, with more complete expansion leading to larger sheets. Optimal processing conditions were identified, involving soaking natural flake graphite in a mixed solution (H₂SO₄:H₂O₂ = 4:1), followed by drying at 60 °C for 24 h. Under these conditions, ultra-large GO sheets were predominantly monolayer with an average size of 220.99 μm and a maximum size of 438 μm. These monolayer GO sheets can be chemically reduced to graphene, making them promising for applications in transparent conductive films, optoelectronic devices, and aligned graphene composites.

As a promising cathode material, olivine-structured LiMnPO₄ holds enormous potential for lithium-ion batteries. Herein, we demonstrate a green biomass-derived phytic-acid-assisted method to synthesize a series of LiMn_1−xFe_xPO₄/C composites. The effect of Fe doping on the crystal structure and morphology of LiMnPO₄ particles is investigated. It is revealed that the optimal Fe doping amount of x = 0.2 enables a substantial enhancement of interfacial charge transfer ability and Li⁺ ion diffusion kinetics. Consequently, a large reversible capacity output of 146 mAh g⁻¹ at 0.05 C and a high rate capacity of 77 mAh g⁻¹ at 2 C were acquired by the as-optimized LiMn_0.8Fe_0.2PO₄/C cathode. Moreover, the LiMn_0.8Fe_0.2PO₄/C delivered a specific capacity of 68 mAh g⁻¹ at 2 C after 500 cycles, with a capacity retention of 88.4%. This work will unveil a green synthesis route for advancing phosphate cathode materials toward practical implementation.

Phase change thermal storage fibers with high latent heat have attracted significant attention in thermal management and heat storage. Through fiber encapsulation, shape-stable phase change materials can be prepared, thereby expanding their applications. In this study, electro-blown spinning was utilized to prepare phase change materials (PCM) using erythritol, with polyethylene oxide (PEO) as the carrier material. Coaxial thermal storage fibers encapsulating the phase change materials were prepared using polyvinyl alcohol (PVA) and polyvinylpyrrolidone (PVP). The results indicate that the composite fibers have a smooth surface, uniform and smooth morphology, a maximum latent heat of 223.01 J/g, as well as excellent thermal stability. The coaxial fibers exhibit a distinct core–shell structure, with the coaxial fibers encapsulated with PVA as the shell material, demonstrating a high latent heat of 118.62 J/g, a residual rate of 93.81% after heating, and excellent thermal performance. The encapsulation efficiency is 53%, effectively addressing the issue of erythritol leakage. The research results provide valuable guidance for the efficient preparation of erythritol coaxial thermal storage fibers.