Boron-nitride nanotubes (BNNTs) are a common one-dimensional (1D) nanostructure that possess piezoelectric potential due to ion-covalent boron-nitride (BN) bonding. Harnessing the advantages offered by high-stability BN structures, these materials have been used for various new applications such as nanogenerators, nanotransistors, and nano-artificial eardrums. In this paper, we used nano-iron oxide red as a catalyst and boron powder in an aqueous dispersion as the boron source to synthesize high-purity O-self-doped BNNTs and film. We investigated the electrical properties of O-self-doped BNNTs and the piezoelectricity of freestanding BNNT film and demonstrated that the electrical properties of O-self-doped BNNTs improved dramatically compared to those of non-doped BNNTs. We also analyzed the band gaps and density of states (DOS) of the O-self-doped BNNTs with the Spanish Initiative for Electronic Simulation with Thousands of Atoms (SIESTA) code to explain the improvement. In addition, we revealed the piezoelectric voltage coefficient g31 of O-self-doped BNNTs (0.28 V m N−1) network films, which can guide future applications for vibration nanosensors and transducers under extreme conditions.
Both sustainable storage of renewable energy using H 2 O 2 as energy carrier and wastewater treatment by electro-Fenton are highly dependent on the efficiency of H 2 O 2 electrosynthesis via 2-electron reduction of O 2 . Rational design of high-performance and cost-effective electrocatalysts with facile preparation is bear the brunt of scalable H 2 O 2 electrosynthesis. Herein, for the first time, we synthesize a pitaya peel-derived formicary-like electrocatalyst employing facile pyrolysis and KOH activation. At the optimal mass ratio of biochar to KOH (1:3), the electrocatalyst exhibits prominent H 2 O 2 activity and selectivity owing to its rich self-doped oxygen-containing functional groups as well as structural defects and sp 3 -C bonds serving as reactive sites, rational hierarchical pores boosting mass transfer of reactants and products, and ultrahigh specific surface area facilitating the exposure of reactive sites. Under natural air diffusion, the pitaya peel-derived catalyst-coated cathode achieves surprising H 2 O 2 productivity of 41.6 mg h −1 cm −2 with current efficiency of 65.5% at large current density of 100 mA cm −2 , meeting the near-industrial requirements for sustainable H 2 O 2 production. Long-term operation stability at large current and rapid degradation of multiple high-concentration organic pollutants demonstrate tremendous potential of the pitaya peel-derived catalysts for H 2 O 2 -based renewable energy storage and environmental remediation.
危险品化学品经营许可证（带存储）