MOF-derived Co9S8nanoparticles embedded in carbon doped with N and S showed super stability and high rate performance for supercapacitors.

No abstract

Radioactive iodine isotopes that are produced in nuclear power plants and used in medical research institutes could be a serious threat to the health of many people if accidentally released to the environment because the thyroid gland can absorb and concentrate them from a liquid. For this reason, uptake of iodide anions was investigated on microrosette-like δ-Bi2O3 (MR-δ-Bi2O3). The MR-δ-Bi2O3 adsorbent showed a very high uptake capacity of 1.44 mmol g(-1) by forming insoluble Bi4I2O5 phase. The MR-δ-Bi2O3 also displayed fast uptake kinetics and could be easily separated from a liquid after use because of its novel morphology. In addition, the adsorbent showed excellent selectivity for I(-) anions in the presence of large concentrations of competitive anions such as Cl(-) and CO3(2-), and could work in a wide pH range of 4-11. This study led to a new and highly efficient Bi-based adsorbent for iodide capture from solutions.

Transition metal phosphides (TMPs) are certified high performance electrocatalysts for the hydrogen evolution reaction (HER). The ultrathin 2D structure of TMPs can offer abundant adsorption sites to boost HER performance. Herein, an ice‐templating strategy is developed to prepare CoP aerogels composed of 2D ultrathin CoP nanosheets (<1.5 nm) using sustainable alginate biomass (seaweed extract) as the precursor. The highly porous aerogel structure can not only deliver facile mass transfer, but also prevent aggregation of the nanosheets into layered structures. As expected, the obtained CoP nanosheet aerogels exhibit remarkable stability and excellent electrocatalytic HER performance at all pH values. For instance, the sample CoP‐400 presents a low overpotential of 113, 154, and 161 mV versus RHE at a current density of 10 mA cm−2 in 0.5 m H2SO4, 1 m KOH, and 1 m phosphate buffer solution, respectively. In addition, CoP‐400 displays low Tafel slopes at all pH values due to the interconnected highly porous structure of the aerogel, indicating that the sample can provide low‐resistance channels for mass transport. Density functional theory calculations reveal that P‐top and Co bridge on (011) facet of CoP are more favorable sites during the process of HER in acid and alkaline solutions, respectively.

Chemically durable and effective absorbent materials for selenite (SeO ) remain highly desirable for contamination remediation. Now a bismuth-based metal-organic framework (Bi-MOF, CAU-17) was used as adsorbent to capture SeO anions from aqueous solution with ultrahigh adsorption capacity of 255.3 mg g and fast kinetics. Furthermore, the adsorbent showed excellent selectivity for SeO and was able to work steadily in a broad pH range of 4-11. Density functional theory (DFT) calculation, XANES modeling, and EXAFS fitting suggested that SeO anions were immobilized by forming Bi-O-Se bonds (T-3 structural model) though splitting the O-Bi-O bond in the crystal structure, leading to a structural transformation of CAU-17 in the solid state.

Pyromellitic dianhydride-based polyimides [C 16 H 6 O 4 N 2 ] n with different crystallinity and morphology were synthesised by simple one-step hydrothermal method. The electrochemical performance and sodium storage mechanism of the polyimide-based organic electrode as anode for sodium-ion batteries were investigated.

A novel supermolecular building blocks (SBBs) based metal−organic framework (MOF), with formula [Zn 7 (TMBHB) was constructed from C 3 -symmetric trimethyl substituted 3,3′,3″,5,5′,5″-benzene-1,3,5-triylhexabenzoic acid (H 6 TMBHB). Notably, the SDU-1 consists of two kinds of rare secondary building units (SBUs), [Zn 2 (COO) 3 ] and [Zn 2 (COO) 4 ], which are linked by TMBHB to form cubic and trisoctahedral SBBs, respectively. TOPOS software analysis of SDU-1 indicates that two alternative simplifications based on different SBBs can produce (3,24)-connected rht or (4,12)-connected ftw topologies. Compared with a recently reported Zn-BHB (H 6 BHB = 3,3′,3″,5,5′,5″benzene-1,3,5-triylhexabenzoic acid) MOF, the structural dissimilarity between them was caused by the steric hindrance of three methyl groups, which makes three isophthalate units on TMBHB nearly perpendicular to the central phenyl ring, giving TMBHB a nonplanar conformation. The photoluminescence behavior of SDU-1 was also discussed.

The CoN3 nanoparticles were controllably synthesized by precisely adjusting the molar ratio of Co/Zn species in the range of 5/95 to 9/91 in Co/Zn-ZIF-67 precursors. The CoN3@NC-7-1000 exhibits remarkable oxygen reduction performance at 0.5 M H2SO4.