Structural, electronic, and thermoelectric properties of hydroxyl groups adsorption on SnO₂ (110) surface: A first-principles study

Structural, electronic, and thermoelectric properties of bridging OHb and terminal OHt groups adsorbed on stoichiometric SnO2 (110) surfaces have been investigated using density functional theory and semiclassical Boltzmann transport theory with effective core pseudopotential implemented in CRYSTAL17 program. Our results indicate that H and OH yield significant structural relaxation around the adsorption sites O-2c and Sn-5c. The results have shown that the absolute value of adsorption energy increases with decreasing the coverage from 1 to 1/4 monolayer. Mulliken charge analysis, band structures, and density of states were calculated and discussed. We found that H and OH adsorption increases the band gap energy from 2.81 eV for clean surfaces to 3.04, 2.95, and 2.89 eV with, respectively, 1, 1/2 and 1/4 monolayer surface coverages. Thermoelectric properties revealed that the presence of hydroxyl groups on the SnO2 (110) surfaces may enhance the Seebeck coefficient, electrical conductivity, and electronic thermal conductivity.