Influence of Pd Clusters Doping on Gas Sensing Properties of TiO₂(101) Nanotubes to SF₆ Decomposition Products

Detection and analysis of sulfur hexafluoride (SF₆) decomposition components is one of the most used methods to realize online monitoring of gas insulated switchgear (GIS) faults. In this paper, Pd₃-doped anatase TiO₂(101) surface was constructed, and studied about its geometric and electronic properties to characteristic SF₆ decomposition products: SOF₂ and SO₂F₂ based on DFT calculations. Comparing with intrinsic TiO₂(101), the conductivity of Pd₃-TiO₂(101) surface decreases dramatically. Studies on adsorption energy, charge transfer, and adsorption distance show that Pd₃-TiO₂(101) shows strong chemisorption to SOF₂ and SO₂F₂ molecules. Based on density of states and molecular orbital theory analysis, it is found that the adsorption of SOF₂ and SO₂F₂ can dramatically change the conductivity in different degrees. As a result, the Pd₃-TiO₂(101) surface exhibits high gas sensitivity and selectivity to SOF₂ and SO₂F₂ molecules. Our calculations would be meaningful for the development of new sensing materials for SF₆ decomposition components detection.