A new nano-sized calcium hydroxide photocatalytic material for the photodegradation of organic dyes

Nano-sized calcium hydroxide (Ca(OH)(2)) photocatalysts were synthesized by a precipitation method. The as-prepared Ca(OH)(2) samples were characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), UV-vis absorption spectroscopy and photoluminescence spectroscopy (PL). The as-obtained Ca(OH)(2) samples showed excellent photocatalytic degradation activities against methylene blue (MB) aqueous solution under visible light radiation. Dependence of the activity on various experimental conditions was investigated, and the results suggested promising utilization of the Ca(OH)(2) photocatalysts. In addition, the photocatalytic degradation of MB was well fitted to pseudo-first-order kinetics. Therefore, MB was photocatalytically degraded over Ca(OH)(2) through indirect dye photosensitization.