CO2 and H2O Coadsorption and Reaction on the Low-Index Surfaces of Tantalum Nitride: A First-Principles DFT-D3 Investigation - data

A comprehensive mechanistic insight into the photocatalytic reduction of CO₂ by H₂O is indispensable for the development of highly efficient and robust photocatalysts for artificial photosynthesis. This work presents first-principles mechanistic insights into the adsorption and activation of CO₂ in the absence and presence of H₂O on the (001), (010), and (110) surfaces of tantalum nitride (Ta₃N₅), a photocatalysts of significant technological interest. The stability of the different Ta₃N surfaces is shown to dictate the strength of adsorption and the extent of activation of CO₂ and H₂O species, which bind strongest to the least stable Ta₃N₅(001) surface and weakest to the most stable Ta₃N₅(110) surface. The adsorption of the CO₂ on the Ta₃N₅(001), (010), and (110) surfaces is demonstrated to be characterized by charge transfer from surface species to the CO₂ molecule, resulting in its activation (i.e., forming negatively charged bent CO₂^−δ species, with elongated C–O bonds confirmed via vibrational frequency analyses). Compared to direct CO₂ dissociation, H₂O dissociates spontaneously on the Ta₃N₅ surfaces, providing the necessary hydrogen source for CO₂ reduction reactions. The coadsorption reactions of CO₂ and H₂O are demonstrated to exhibit the strongest attractive interactions on the (010) surface, giving rise to proton transfer to the CO₂ molecule, which causes its spontaneous dissociation to form CO and 2OH⁻ species. These results demonstrate that Ta₃N₅, a narrow bandgap photocatalyst able to absorb visible light, can efficiently activate the CO₂ molecule and photocatalytically reduce it with water to produce value-added fuels.

The data underpinning the research are available in the .xlsx format (can be viewed either by MS Office or Libre Office) comprising 6 datasheets, which gives information about the bulk structure of Ta3N5; structures of the (001), (010) & (110) surface; CO2 and H2O adsorption structures adsorption on (001), (010), and (110) surfaces of tantalum nitride (Ta3N5). Data for the optimized structures are available in CONTCAR format of the VASP simulation program. The CONTCAR files consist of lattice parameters and atomic positions and can be viewed either by MS Office or WordPad and displayed using VESTA software.

Research results based upon these data are published at https://doi.org/10.3390/catal10101217