5Mixed transition metal oxides have attracted much attention recently due to their potential application in the energy and environmental sciences. The emergency of multivariate MOFs recently attracts great research attention and provides an opportunity for multivariate mixed-metal oxides. In this work, five isostructural, single-phase MOF-74 structures with different divalent metals (MOF-74-Co, MOF-74-Ni, MOF-74-NiCo1, MOF-74-NiCo2 and MOF-74-NiCo4) were synthesised by varying the mole ratios of 10 Ni/Co mixed-metal ions. After annealing at the proper temperature, Co 3 O 4 , NiO and three kinds of Ni x Co 3-x O 4 mixed-metal oxide nanoparticles with the high surface area were easily obtained and the metal ratio was readily controlled, enabling us to systematically investigate the effect of different metal species amounts on the electrochemical properties of the mixed-metal oxide materials. When these metal oxides were used as electrode materials for supercapacitors, we found that the mixed-metal oxides Ni x Co 3-x O 4 15 obtained from bimetallic MOF-74-NiCo structures had obvious advantages compared with the monometallic oxides of MOF-74-Ni and MOF-74-Co. Especially, the NixCo 3-x O 4 -1 with the Ni/Co metal ratio 1:1 exhibited the highest capacitance of 797 F g -1 and excellent cycling stability.

Incorporation of carbon into BN porous materials (BCN) increases ultramicropores (<0.7 nm) and chemical defects, improving the CO2 capacity to 3.74–3.91 mmol CO2 g−1 at 298 K and ambient pressure.