Photoelectrochemical response of TlVO₄ and InVO ₄:TlVO₄ composite

This work presents photoelectrochemical characteristics of TlVO ₄, a previously uncharacterized candidate for photocatalytic water splitting. Additionally, a composite of InVO₄ and TlVO₄ was synthesized by a facile solution method using orthorhombic InVO₄ as a seed for growth of crystallographically similar orthorhombic TlVO ₄. Photoelectrochemical measurements indicate an increase in photocurrent and more negative flatband potentials for TlVO₄ and the InVO₄:TlVO₄ composite relative to InVO₄. Diffuse reflectance UV-visible measurements were used to determine bandgaps of 3.50 eV, 2.94 eV, and 2.98 eV for InVO₄, TlVO₄, and InVO₄:TlVO₄, respectively. Density functional theory (DFT) calculations were performed to elucidate the band structures and correlate well with experimental data. The results indicate higher photoelectrochemical activity for TlVO₄ and the InVO₄:TlVO₄ composite relative to InVO₄.