Enhanced visible-light photocatalytic activity of a g-C3N4/BiVO4 nanocomposite: a first-principles study†
Abstract
The structural, electronic, and optical properties of a g-C3N4(001)/BiVO4(010) nanocomposite have been investigated using first-principles calculations. The results indicate that g-C3N4(001) can stably adsorb onto the BiVO4(010) surface, and it tends to form a regular wavy shape. The calculated band gap of the g-C3N4(001)/BiVO4(010) nanocomposite is narrower compared with that of BiVO4 or BiVO4(010), primarily due to the introduction of N 2p states near the Fermi level. The g-C3N4(001)/BiVO4(010) nanocomposite has a favorable type-II band alignment; thus, photoexcited electrons can be injected into the conduction band of g-C3N4(001) from the conduction band of BiVO4(010). The proper interface charge distribution facilitates carrier separation in the g-C3N4(001)/BiVO4(010) interface region. The electron injection and carrier separation can prevent the recombination of electron–hole pairs. The calculated absorption coefficients indicate an obvious redshift of the absorption edge, which is in good agreement with the experimental results. Our calculation results suggest that the g-C3N4(001)/BiVO4(010) nanocomposite has significant advantages for visible-light photocatalysis.