Synthesis, structure, and improved photo/electrocatalytic performance of Co- and Ni-based metal-organic frameworks (MOFs) by using mixed ligands of 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene (4-bpd) and 1,3-dicarboxyadamantane (H2adc)

Four MOFs with two identical structures were constructed by using 1,4-bis(4-pyridyl)-2,3-diaza-1,3-butadiene (4-bpd) and 1,3-dicarboxyadamantane (H2adc) as linkers, and Co2+, Ni2+ as metal nodes by solvothermal method. Single-crystal X-ray diffraction revealed that complexes [Co2(adc)2(4-bpd)]n (1) and [Ni2(adc)2(4-bpd)]n (2) have the same two-dimensional molecular structure, while complexes [Ni(Hadc)2(H2O)2]n (3) and [Co (Hadc)2(H2O)2]n (4) exhibit identical one-dimensional chain-like molecular structures. The photo/electrocatalytic performances and thermal stability of four complexes were investigated. Introducing 4-bpd to form mixed-ligand complexes 1 and 2 enables the degradation of crystal violet (CV) dye in a Fenton-like system. Furthermore, there is an improvement in the oxygen evolution reaction (OER) catalytic performance among the MOFs of the same metal nodes. It is worth mentioning that in this study, Co-based MOFs showed better catalytic performance than Ni-based MOFs, which is mainly attributed to the distinctive electronic structure of Co2+ and Ni2+ d orbitals.