Band Gap Energy of Periodic Anatase TiO2 System Evaluated with the B2PLYP Double Hybrid Functional

Abstract

The electronic properties of anatase titanium dioxide (TiO2) materials are of paramount importance for photocatalytic application. Ab initio calculation is performed on anatase TiO2 with various cluster sizes and shape, using Gaussian 09 program employing the standard 6-311G(d) and 3-21G basis set. Hartree-Fock (HF) theory, exchange-functional of density functional theory including hybrid (B3LYP, B3PW91, PBE1PBE and PBEh1PBE) and double-hybrid (B2PLYP), together with 2nd order Møller-Plesset perturbation theory are used to predict the band gap energy of anatase TiO2. With the inclusion of long-range HF exchange, double hybrid B2PLYP functional is able to predict band gap energy value (3.06 eV) which as compared to the experimental value (3.20 eV). Besides, this double hybrid exchange-correlation functional shows good compromise by obtaining an accurate description for cohesive energy of anatase TiO2. Thus, double-hybrid B2PLYP functional is suggested to be a practical choice for predicting the electronic properties for anatase TiO2.