Boron nitride nanotubes (BNNTs), structural analogues of carbon nanotubes, have attracted significant attention due to their superb thermal conductivity, wide bandgap, excellent hydrogen storage capacity, and thermal and chemical stability. Despite considerable progress in the preparation and surface functionalization of BNNTs, it remains a challenge to assemble one-dimensional BNNTs into three-dimensional (3D) architectures (such as aerogels) for practical applications. Here, we report a highly compressive BNNT aerogel reinforced with reduced graphene oxide (rGO) fabricated using a freeze-drying method. The reinforcement effect of rGO and 3D honeycomb-like framework offer the BNNTs/rGO aerogel with a high compression resilience. The BNNTs/rGO aerogels were then infiltrated with polyethylene glycol to prepare a kind of phase change materials. The prepared phase change material composites show zero leakage even at 100 °C and enhanced thermal conductivity, due to the 3D porous structure of the BNNTs/rGO aerogel. This work provides a simple method for the preparation of 3D BNNTs/rGO aerogels for many potential applications, such as high-performance polymer composites.

Flexible thermoelectric materials that can harvest waste heat energy have attracted great attention because of the rapid progress of flexible electronics. Ag 2 Te nanowires (Ag 2 Te NWs) are considered as promising thermoelectric materials to fabricate flexible thermoelectric film and device because of their high Seebeck coefficient, but poor contact between the Ag 2 Te NWs results in low electrical conductivity. Generally, hot or cold pressing can increase the electrical conductivity between the Ag 2 Te NWs. However, these process tend to destroy the initial morphology of the Ag 2 Te NWs and/or cause only physical contact between the Ag 2 Te NWs. Herein, we report an approach to the room-temperature welding of Ag 2 Te NWs to enhance their contacts by facile combination of vacuum filtration and dropcoating methods. The obtained Ag 2 Te NWs film exhibits excellent Seebeck coefficient of −99.48 μV/K and high electrical conductivity of 15 335.05 S/m at room temperature, which gives the power factor of 151.76 μW m −1 K −2 . Surprisingly, an optimal Seebeck coefficient of −154.96 μV/K and electrical conductivity of 14 982.42 S/m can be obtained at 420 K, giving a power factor of 359.76 μW m −1 K −2 . Moreover, the electrical resistance of the Ag 2 Te NWs film was only 1.3 times of the initial electrical resistance after 1000 bending cycles, indicating good flexibility of the film. A finger-touch test is conducted by using the Ag 2 Te NWs film as thermoelectric power generator, which achieves a stable output voltage of about 0.52 mV, suggesting its great potential applications in self-powered flexible electronic devices.