Schematic illustration of the synthesis of the Zn_1−xCo_x/NC catalyst.

The zeolitic imidazolate framework-8 (ZIF-8), as a kind of MOF, is widely used in sensors, gas storage/separation, drug delivery, and catalysis due to its adjustable porous structure, high surface area, and excellent chemistry tunability. ZIF-8 is constructed by Zn²⁺ and 2-methylimidazole and synthesized in the methanol solution. In this paper, we explored the influence of the reused methanol solution for the structure and properties of the synthesized ZIF-8. The as-synthesized ZIF-8 was characterized by an X-ray diffraction instrument (XRD), a scanning electron microscope (SEM), a specific surface area analyzer (BET), and Fourier transform infrared spectroscopy (FT-IR). The results show that the reused methanol solution does not change the phase, porous structure, and BET surface area of ZIF-8. However, the particle size of ZIF-8 increases from 50 nm to 5 um and the productive rate decreases to 7.4% when the methanol solution is reused four times. This work provides new insight into the reuse of dissolvents for the synthesis of MOFs.

Nowadays, aflatoxin B₁ (AFB₁) contamination is considered as one of the most common food safety issues for humans and animals.

Kaolin clay is an inexpensive and abundant material with potential for use as a low-dielectric-constant ceramic; however, the natural metallic oxides the clay contains hinder such applications. In this study, kaolin clay ceramics with excellent physical and dielectric properties were synthesized using kaolin clay as the raw material by chemical cleaning and sintering. Characterization of the resulting samples showed that the sulfuric acid treatment has a significant influence on the metallic oxide content and dielectric properties of the kaolin clay ceramics. When the kaolin clay raw material was treated with sulfuric acid three times, the dielectric constant decreased from 5.12 to 3.75 and the Vickers hardness increased from 946 to 1,214 kg/mm² relative to the ceramic prepared from the untreated clay. Therefore, these ceramics exhibit significant potential for use in the microelectronics industry.

Correction for ‘Influence of Zn and Co co-doping on oxygen evolution reaction electrocatalysis at MOF-derived N-doped carbon electrodes’ by Xiaobing Yang et al., Inorg. Chem. Front., 2019, DOI: 10.1039/c9qi00334g.