A fair comparison between bismuth catalysts for application in photodegradation under visible and solar light

ABSTRACT Three different bismuth catalysts (Bi2WO6, BiOI and BiVO4) were synthesized using solvo- and hydrothermal methods. Different reaction times, calcination and the addition of poly (vinyl pyrrolidone) during synthesis were tested to investigate the effect of these variables on the catalysts ’ morphology and photocatalytic activity. The photocatalytic activity was evaluated using the degradation of rhodamine B dye under both visible light and natural solar radiation. The Bi2WO6 samples presented good crystallinity and morphological similarities, despite having undergone different treatments. The BiOI and Bi2WO6 catalysts presented a spherical shape, and no morphological difference was observed as a result of the addition of PVP. The BiVO4 sample presented a parallelepiped shape. BiOI containing PVP and ethylene glycol was the catalyst that presented the highest activity, while BiVO4 presented the lowest. In experiments using scavengers, photogenerated holes demonstrated a key role in dye degradation.
Source: Brazilian Journal of Chemical Engineering - Category: Chemistry Source Type: research