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In this work, a strategy to incorporate lithium into the bimetallic NiCo MOF (Li–NiCo MOF) is proposed by a simple hydrothermal process to architect the structure and tune the electronic properties of the electrodes. The electrochemical results show that the reversibility of Li-ion storage in the Li–NiCo MOF half-cell composite is significantly higher than that of NiCo MOF, and it shows excellent rate performance, charging capability, and stable long cycle life. Moreover, the effective process of lithium incorporation by the hydrothermal method (in situ) improves the charge-storage properties and is also compared with the lithium incorporation achieved by the sonochemical method. The experimental findings are correlated with the incorporation of Li into the O–Co–O and M2O4 sites of the NiCo MOF by density functional theory calculations. The results confirm the reduction of band energy and, consequently, an increase in the electronic conductivity and charge transport. Furthermore, Li incorporation at O–Co–O sites shows better Li diffusion properties confirmed by the reduction of diffusion barrier potential, compared to the pristine NiCo MOF. A solid-state lithium-ion capacitor (Li–NiCo MOF//AC) is fabricated, which achieves a high energy density of 145 W h kg−1 while maintaining a power density of 400 W kg−1 and depicts a high power density of 4000 W kg−1 at 40.2 W h kg−1 of energy density. The capacitor device exhibits excellent electrochemical structural stability, and can still maintain an original capacity of 85% after 3000 charging–discharging cycles. Thus, lithium incorporation into the MOF structures could be of great significance for improving lithium storage and LIC device performance. [ABSTRACT FROM AUTHOR]

Nanocarbon-based frustrated Lewis pair (FLP) bifunctional catalysts, on account of their unquenched electron transfer property, are becoming increasingly attractive as catalysts for the CO2 reduction reaction via the dissociative chemisorption of H2. In the present study, we propose a nanocarbon-based FLP catalyst. The pair comprises nitrogen doped/phosphorus doped graphene as Lewis bases and M(C6F5)3 (M = B, Al, Ga, and In) as Lewis acids. The computational investigation reveals that the carbon atoms adjacent to the doped N and P atoms are the active sites towards the dissociative chemisorption of hydrogen molecule. The analyses of the Bader charges and difference charge densities validate the dissociative chemisorption of H2 molecule and the fact that a significant electron redistribution promotes the polarization of the hydrogen molecule. Density of states confirms the hybridization between the p-states of the nitrogen/phosphorus atom and the s-state of hydrogen atom in all FLPs. The dissociative chemisorption of hydrogen is noted in all FLP complexes, thereby facilitating a low barrier reaction path for CO2 reduction. Between P-doped and N-doped FLPs, N-doped FLP catalysts prove to be a more promising counterpart with considerably low activation barriers, ranging between 0.01 and 0.11 eV, towards CO2 reduction. Thus, the present study demonstrates the great potential of doped carbon-based FLPs as novel nanostructure catalysts for CO2 reduction via the direct utilization of molecular hydrogen. [ABSTRACT FROM AUTHOR]