Computational and experimental studies of the wide bandgap semiconductors NH 4 TiOF 3 and (NH 4 ) 2 TiOF 4 .

As the topotactic synthetic precursor of the ubiquitous functional semiconductor anatase TiO 2 , ammonium fluoroxotitanates, such as NH 4 TiOF 3 and (NH 4 ) 2 TiOF 4 , have received lots of research interest as synthetic precursors. However, few of the existing studies focus on their properties and possible applications on their own. To fill this gap, both NH 4 TiOF 3 and (NH 4 ) 2 TiOF 4 were studied in this work experimentally by material characterization and computationally via DFT calculations. Electronic structures of both materials from experimental and computational perspectives were mutually supportive. Based on these, immobilised NH 4 TiOF 3 was preliminarily tested as a UV photocatalyst for dye degradation. Reasonable photocatalytic activities were observed.