Conductive confinement of sulfur and polysulfide via carbonaceous blocking layers can simultaneously address the low conductivity, volume expansion of sulfur during charge/discharge process and polysulfides shuttling effect in lithium-sulfur (Li-S) batteries. Herein, conductive and porous nitrogen and phosphorus dual doped graphene (p-NP-G) blocking layer is prepared via a thermal annealing and subsequent hydrothermal reaction route. The doping levels of N and P in p-NP-G measured by the X-ray photoelectron spectroscopy are ca. 4.38% and ca. 1.93 %, respectively. The dual doped blocking layer exhibits higher conductivity than N or P single doped blocking layer. More importantly, the density function theory (DFT) calculation demonstrates that P atoms and -P-O groups in the p-NP-G layer offer stronger adsorption to polysulfides than the N species. The electrochemical evaluation results illustrate that the p-NP-G blocking layer could deliver superior initial capacity (1158.3 mA h/g at the current density of 1 C), excellent rate capability (633.7 mA h/g at 2 C), and satisfactory cycling stability (ca. 0.09% capacity decay per cycle), which are better than the N or P single doped graphene. This work suggests that this synergetic combination of conductive and adsorptive confinement strategies induced by the multi-heteroatoms doping scheme is a promising approach for developing high performance Li-S batteries.

Stimuli-controlled drug delivery and release is of great significance in cancer therapy, making a stimuli-responsive drug carrier highly demanded. Herein, a multistimuli-controlled drug carrier was developed by coating bovine serum albumin on Fe5C2 nanoparticles (NPs). With a high loading of the anticancer drug doxorubicin, the nanoplatform provides a burst drug release when exposed to near-infrared (NIR) light or acidic conditions. In vitro experiment demonstrated a NIR-regulated cell inhibition that is ascribed from cellular uptake of the carrier and the combination of photothermal therapy and enhanced drug release. The carrier is also magnetic-field-responsive, which enables targeted drug delivery under the guidance of a magnetic field and monitors the theranostic effect by magnetic resonance imaging. In vivo synergistic effect demonstrates that the magnetic-driven accumulation of NPs can induce a complete tumor inhibition without appreciable side effects to the treated mice by NIR irradiation, due to the combined photochemotherapy. Our results highlight the great potential of Fe5C2 NPs as a remote-controlled platform for photochemothermal cancer therapy.

Natural bamboo, as a sustainable precursor, is used to prepare porous bamboo carbon fibers (BCFs) that are subsequently interwoven into a BCF membrane (BCFM) as a captor interlayer for the lithium polysulfide intermediates between the sulfur cathode and the separator in Li–S batteries.