Identification of Fe and Zr oxide phases in an iron-zirconium binary oxide and arsenate complexes adsorbed onto their surfaces.

•The components, active sites and synergistic effect of Fe-Zr oxide were investigated.•The unknowns were explored using multiple techniques combined with DFT calculations.•The synergistic effect between Fe and Zr oxides after doping were well elucidated.•As(V) adsorption chemistry on Fe-Zr oxide was well understood in this work.•This work sheds light on synergistic effects that occur on this surface.