Photoelectrochemical Response of TlVO4 and InVO4:TlVO4 Composite

This work presents photoelectrochemical characteristics of TlVO4, 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 TlVO4. 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.