Tuning the electronic and adsorption properties of MoSe2 nanosheets by CuO, NiO and pair CuO-NiO metal oxide doping for efficient sensing of caffeine molecule: A DFT study

In this work, the structures and electronic properties of CuO and NiO doped MoSe₂ nanosheets are investigated using the density functional theory calculations. The structural stability of these metal oxide doped systems was verified using the binding energy analysis, and thus the CuO doped MoSe₂ nanosheets are selected for adsorption and sensing of caffeine molecules. The adsorption energies, density of states, charge density difference, work functions and band structures were examined for the adsorption systems. Caffeine molecules are initially positioned on the CuO clusters of the CuO-MoSe₂ nanosheets, and after the adsorption, the O and N atoms are strongly adsorbed to the CuO clusters. Based on band structure calculations, CuO and NiO doped MoSe₂ nanosheets exhibited semiconductor property and enhanced conductivity because of band gap reduction. These results provide theoretical basis, which is useful in optimizing and developing novel metal oxide doped MoSe₂ nanosheets as sensors for caffeine detection.