Analysis of the structural and electronic properties of TiO2 under pressure using density functional theory and equation of state

Rutile Phase Titanium dioxide, or TiO₂, has been the subject of substantial research due to its semiconductor properties, finding applications in areas such as photocatalysis, photovoltaics, and sensor technology. Here, we present a density functional theory analysis focused on the structural and electronic characteristics of rutile TiO₂ as pressure is applied up to 12GPa. Our calculations are performed using the generalised gradient approximation and projector-augmented wave methods to optimise the lattice constants, calculate cohesive energies, and evaluate the effect of pressure on the band gap. The results generally indicate a consistent decline in lattice volume and an increase in bulk modulus, which we observed with increased pressure, as well as a narrowing of the band gap that can be attributed to intensified Ti-O interactions. What is particularly interesting is that our calculated data aligns well with both experimental data and theoretical values, all of which were obtained using the equation of state. In my opinion, this supports the notion that density functional theory is a reliable method for predicting the behaviour of materials under compression. This study provides a deeper understanding of how pressure affects TiO₂, which is crucial for high-pressure applications and device engineering.