Herein three novel cobalt metal-organic frameworks (Co-MOFs) with similar ingredients, [Co(bib)(o-bdc)] (1), [Co(bib)(m-bdc)] (2), and {[Co(bib)(p-bdc)(HO)](HO)} (3), have been synthesized from the reaction of cobalt nitrate with 1,4-bis(imidazol-1-yl)benzene (bib) and structure-related aromatic acids (1,2-benzenedicarboxylic acid = o-bdc, 1,3-benzenedicarboxylic acid = m-bdc, and 1,4-benzenedicarboxylic acid = p-bdc) by the solvothermal method. It is aimed to perform systematic research on the relationship among the conformation of benzoate acid, lattice dimension of Co-MOF, and pore diameter of MOF-derived carbon composite. Through the precursor strategy, Co-MOFs 1-3 have been utilized to synthesize porous cobalt@carbon nanotube composites (Co@CNTs). After the in situ gas-sulfurization, secondary composites CoS@CNTs were successfully obtained, which kept similar morphologies of corresponding Co@CNTs without destroying previous highly dispersed structures. Co-MOFs and two series of composites (Co@CNTs and CoS@CNTs) have been well characterized. Topology and Brunauer-Emmett-Teller analyses elucidate that the bdc ion could control the pore diameters of MOF-derived carbon composites by adjusting the lattice dimension of Co-MOFs. The systematic studies on electrochemical properties demonstrate that (p)-CoS@CNT possesses hierarchical morphology, moderate specific surface area, proper pore diameter distribution, and high graphitization, which lead to remarkable specific capacitances (839 F g at 5 mV s and 825 F g at 0.5 A g) in 2 M potassium hydroxide solution. In addition, the (p)-CoS@CNT electrode exhibits good electrochemical stability and still retains 82.9% of initial specific capacitance at the current density of 1 A g after 5000 cycles.

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A DeNOx project case was built to explore the industrial feasibility of low temperature DeNOx in the presence of SOx.

Halide perovskite, an ionic semiconductor, with the typically structural composition of ABX 3 has become the extremely popular star in optoelectronics due to its superior photophysical properties and easily solution processing. In comparison with the traditional semiconductors, the perovskite possesses a low crystal formation energy with facile solution synthesis, which results into its soft and dynamic crystal lattice. Therefore, the post-synthetic composition tuning via ion exchange has been proved to be an effective technique to introduce heteroatoms into perovskite lattice. In this review, we summarize the recent progress on ion exchange of halide perovskites, including mechanisms, methods, as well as different scales from low-dimensional nanoscale to bulk crystal. Besides, we also briefly discuss the prospective of ion exchange for halide perovskites, and hope it benefit for the structural design and compositional optimization in halide perovskites for various optoelectronic applications.