High efficient and selective removal of Pb2+ through formation of lead molybdate on α-MoO3 porous nanosheets array

2D hand-like structured α-MoO3 porous nanosheets were grown in-situ onto a capillary by a simple hydrothermal route, on which titanium dioxide seed layer was sol-dip-coated in advance. The α-MoO3 porous nanosheets array exhibits an exceptional lead ion uptake capacity up to 1450.0mg·g-1, and can effectively reduce Pb2+ concentration from 20mg·L-1 to a low level of smaller than 3μg·L-1, well below the acceptable limits in drinking water standards (10μg·L-1) and can efficiently remove 99.9% lead ion within a few minutes at room temperature. Furthermore, α-MoO3 porous nanosheets array also has high selectivity toward Pb2+ better than Cu2+, Zn2+, Cr3+ and Cd2+. The mechanism for adsorption was discussed according to the results of Zeta potential, IR, XPS and XRD analyses. The excellent removal performance of the array to Pb2+ is resulted from the electrostatic adsorption interaction and the formation of new species lead molybdate.