A Trinuclear Cobalt–Organic Framework: Solvatochromic Sensor towards CH2Cl2, and its Derivative as an Anode of Lithium-Ion Batteries with High Performance

Here, a porous cobalt–organic framework with pillared layer structures, namely Co₃OBA₃PTD(H₂O)₂ ⋅ 2 DMA ⋅ H₂O]_n ( 1 , H₂OBA=4,4′-oxybis(benzoic acid); PTD=6-(pyridin-4-yl)-1,3,5-triazine-2,4-diamine), was fabricated by using cobalt trinuclear nodes, low-cost carboxylic linker, and accessible nitrogen heterocyclic ligands. This compound exhibited a highly efficient solvatochromism towards CH₂Cl₂ within one minute and can be used 200 times at least. The corresponding dropper detector was assembled as a practical sensor. Meanwhile, the porous Co₃O₄ was obtained by a simple but effective annealing treatment. Electrochemical measurements confirm that this Co₃O₄ material derived from compound 1 shows high and stable lithium storage capabilities (1081.75 mA h g⁻¹ at 200 mA g⁻¹ after 115 cycles) and excellent rate properties.