The effect of Pt and IrO2 interlayers on enhancing the adhesion of Ti/SnO2 interface: A first principles density functional theory study

With potential applications from gas sensors to anode electrodes, Ti/SnO2 interfacial systems play a crucial role in the detection of harmful gases and the destruction of refractory organic pollutants via electrochemical advanced oxidation processes. However, there is an issue with the stability of the Ti/SnO2 interface, in which having an interlayer of another metal or ceramic may work to improve it. First principles density functional theory calculations were performed to study how the addition of Pt and/or IrO2 interlayers affect the stability and adhesion of Ti/SnO2. The calculations showed that Ti/SnO2 interfaces are destabilized by the movement of oxygens from the surface of SnO2 into the Ti phase, causing the adhesion between the newly oxidized Ti phase to be weak with the surface Sn atoms. In contrast, both Pt and IrO2 were found to form stable interfaces with both Ti and SnO2. Further investigation found that Ti/Pt/SnO2 and Ti/IrO2/SnO2 formed stable systems that promoted adhesion between all phases. However, having both Pt and IrO2 combined as interlayers did not form a stable system. Overall, the results show that both Pt and IrO2 may serve as potential interlayer for Ti/SnO2 that promotes adhesion, but combined together they do not.