New AgNbO4−δ compound with high visible light photocatalytic activity

• A new visible light responsive AgNbO4−δ photocatalyst was synthesized.
• The AgNbO4−δ compound has a tetragonal scheelite (ABO4) type structure.
• The AgNbO4−δ compound has a narrow band gap of about 2.08 eV.
• The AgNbO4−δ compound exhibits a high photocatalytic activity.

A new visible light responsive silver niobate photocatalyst AgNbO4−δ was synthesized by using a low-temperature chemical precipitation method. X-ray diffraction (XRD) results indicated that the AgNbO4−δ compound has a tetragonal scheelite (ABO4) type structure. It has also an optical absorption edge at about 596 nm, corresponding to a bandgap of about 2.08 eV. In addition, its microstructure and element composition were studied by using scanning electron microscopy (SEM), energy dispersive spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS). Furthermore, its photocatalytic activities were evaluated in terms of degradation of Rhodamine B, showing that the as-prepared AgNbO4−δ compound has higher photocatalytic activity than P25.