Photocatalytic degradation of two different types of dyes by synthesized La/Bi2WO6

摘要

A lanthanum doped Bi _(2) WO _(6) composite (La/Bi _(2) WO _(6) ) was prepared using a simple hydrothermal method. The synthesized samples were well characterized using XRD, SEM, TEM, UV-vis DRS, XPS, and BET analysis methods. The photocatalytic activities of La/Bi _(2) WO _(6) on reactive brilliant red X-3B (X-3B) and rhodamine B (RhB), under simulated solar irradiation, were systematically investigated. As a result, the doped Bi _(2) WO _(6) samples possessed a higher specific surface area than pure Bi _(2) WO _(6) , but still retained the crystalline phases, morphology and visible light absorption properties of pure Bi _(2) WO _(6) . The initial concentrations of dyes, the dosage of catalyst and H _(2) O _(2) all displayed the same effects on the degradation of the two dyes. However, pH showed different effects on X-3B and RhB because X-3B is an anionic dye while RhB is a cationic dye. Moreover, among all the inorganic ions studied (Na ~(+) , K ~(+) , Ca ~(2+) , Mg ~(2+) , NO _(3) ~(?) , HCO _(3) ~(?) , Cl ~(?) , SO _(4) ~(2?) ), the addition of Cl ~(?) significantly affected the adsorption and degradation of the two dyes; Cl ~(?) inhibited the total removal efficiency of X-3B, but enhanced the removal efficiency of RhB. The effects of inorganic cations were attributed to the effect of Cl ~(?) because the four metal ions were used as their chloride salts.