A thermally reduced graphene oxide film (r-GOF), with tailorable micro-structures and macro-properties, is fabricated by annealing a filtrated graphene oxide film (GOF) in a confined space. The structural evolution of the film at different annealing temperatures is systematically investigated, and further correlated to the thermal conductivity and mechanical performances. With the increase of temperature, more oxygen-containing functional groups are removed from the film by a simultaneous conversion from sp³ to sp² carbon in the graphitic lattice. As the temperature reached 1200 °C, the r-GOF achieves an ultrahigh thermal conductivity of ca. 1043.5 W m⁻¹ K⁻¹, while 1000 °C is a critical temperature in enhancing the thermal conductivity. Moreover, G1200 exhibits excellent mechanical stiffness and flexibility with a high tensile strength (13.62 MPa) and Young's modulus (2.31 GPa). The combined conductivity and mechanical performances render the r-GOFs promising materials as flexible lateral heat spreaders for electronics.

T-Nb₂O₅/graphene nanocomposites were fabricated and then paired with mesoporous carbon electrodes to construct the asymmetrical supercapacitors with high energy and power densities.

Near infrared (NIR)-light emitting fluorescent probes have attracted extensive research attention in the bioimaging field due to their deep tissue penetration, minimal auto-fluorescence and lower emission light damage to bio-tissues. Herein, we designed and prepared NIR-light emitting CDs (R-CDs) from spinach by a one-step solvothermal method. The R-CDs exhibited good water solubility, a maximum fluorescence emission peak at 680 nm, a high quantum yield of 15.34%, remarkable photo-stability and resistance to metal ions in a body-simulating environment, excellent compatibility, negligible toxicity, and superior labelling capability in vitro and in vivo. These findings significantly highlight the design of NIR-light emitting CDs and exploit their bio-imaging applications.

A new two-step process was developed to prepare PVDF/reduced graphene oxide (PVDF/rGO) composite films: the synthesis of PVDF/GO composite films and immersion of such films in hydrobromic acids for reduction. This method avoided the agglomeration of rGO during reduction in PVDF/GO solutions and efficiently improved the dispersion effect of rGO in the PVDF matrix. Meanwhile, it simplified the preparation process due to no modification of GO being required, and opened a feasible way to scale up the production of PVDF/rGO composites. Experiments showed that PVDF with nearly all β phase was obtained when the content of rGO was 0.1 wt% (PrGO-0.1), and the dielectric constant increased from 10 for the neat PVDF to 41 for PrGO-0.1 at 1 kHz. The ferroelectric, piezoelectric, and dynamic mechanical properties of the PVDF/rGO composites were also comprehensively studied. As the content of the β phase was nearly 100%, the piezoelectric constant and remnant polarization of the PrGO-0.1 film increased by 78.6% and 69.3%, respectively, compared with those of the neat PVDF, and therefore became the highest among all composite films. The rGO also, to a great extent, helped to enhance the mechanical properties of the PVDF composites. As a result, the improved piezoelectric and ferroelectric properties made the PVDF/rGO composite films with 0.1 wt% rGO content much better piezoelectric energy transfer and ferroelectric storage materials than the neat PVDF.

Polyacrylonitrile/lignin sulfonate (PAN/LS) blend fibers were spun via a wet spinning process. The fiber structure, mechanical properties and thermal stability of the precursor fibers were studied by FT-IR, SEM, tensile tester, and TG-DSC. Results indicated that there was no chemical crosslinking between PAN and LS during the process of wet spinning. PAN and LS had good compatibility in the blend fibers. LS could weaken the skin of the blend fibers and reduce the fiber structure defects. The increase of dope concentration could improve the fiber structure and mechanical properties. LS blending with PAN could reduce fiber weight loss in the thermal stabilization process, and most importantly the precursor fibers could be stabilized rapidly without fiber fusion. Through polymer blending and wet spinning, this study provided a promising way to prepare a precursor fiber for carbon fiber.

Owing to the high theoretical specific capacity of sulfur (1675 mA h g⁻¹), lithium–sulfur batteries display fascinating potential for high-capacity energy storage. However, their practical applications are still hindered by the fast capacity decay and poor cycling stability. In this work, a sulfur host based on MOF-derived cobalt–graphitic carbon nanocages is prepared by annealing the MOF (ZIF-67) in a H₂/Ar atmosphere. This unique structure can provide both the physical encapsulation of polysulfides by the graphitic carbon shell and chemical entrapment of polysulfides by the Co nanoparticles embedded in the carbon shell. In addition, the nanocages with inner void space not only allow a relatively higher loading content of sulfur but also alleviate the volume expansion of sulfur upon lithiation. As a result, the GC–Co electrodes with a high sulfur loading content of 77 wt% display a high specific capacity at different current densities and long-term cycling performance of 500 cycles at 1C with an ultra-low capacity decay of 0.015% per cycle.