tocatalytic reduction of CO 2 into methanol, formic acid, methane and formaldehyde using semiconductor catalysts such as TiO 2 , ZnO, CdS, GaP and WO 3 . After that a variety of catalysts including metal oxides [11−13], sulfides [14,15] and titanium-based materials [16−21] have been investigated for the efficient conversion of CO 2 into either gas or liquid products. Recently, the peroveskite type materials ABO 3 (such as SrTiO 3 , BiVO 4 , SrZrO 3 , etc.) have been drawn much attention for photocatalysis, due to their nontoxicity and stability [22,23]. Among them, SrZrO 3 is an n-type perovskite semiconductor with a wide band gap, and it has been used as photocatalyst, proton-conductor material, high voltage and high reliability capacitor [24,25]. Recently, Tian et al. [26] synthesized SrZrO 3 with a small amount of MoS 2 loaded on the surface of SrZrO 3 and applied the material as the photocatalyst for H 2 evolution. The result indicated that SrZrO 3 exhibited great potential in photocatalytic field. Because of its excellent stability and optical property, SrZrO 3 can also be suitable for CO 2 reduction under UV light irradiation, whereas there are scarcely ever studies on it.In this paper, we synthesized SrZrO 3 by a sonochemical method and reported the performance of photocatalytic conversion of dissolved CO 2 in water under a 300 W Xenon lamp. The possible mechanism of the photoreduction of CO 2 by SrZrO 3 was also proposed. EXPERIMENTAL ChemicalsThe chemicals used for the synthesis of SrZrO 3 are Sr(NO 3 ) 2 (99.5%), ZrOCl 2 •8H 2 O (>99%), cetyltrimethyl ammonium bromide (99%), KOH (analytical grade >82%), Pb(NO 3 ) 2 (>99%) and thioacetamide (C 2 H 5 NS>99%). All the chemicals were purchased from Sinopharm Chemicals and were used as received without further treatment.The utilization of CO2 and solar energy have drawn much attention due to global warming and fuel crisis. Of particular interest in our research, we prepared strontium zirconate (SrZrO3) nanoparticles as the photocatalyst to convert CO2 into value-added products. SrZrO3 nanoparticles were successfully synthesized via a sonochemical method and applied to the photoreduction of CO2. The samples were characterized by X-ray diffraction, Raman spectroscopy, scanning electron microscopy, Brunauere Emmette Teller measurement, X-ray photoelectron spectroscopy and UV-vis absorption spectroscopy. Ethanol, methane and carbon monoxide were the major products with the yield respectively as follows, 41 μmol g -1 , 2.57 μmol g -1 and 1.6 μmol g -1 after 4 h of reaction. The reason for the multiple photoreduction products is briefly discussed. Our work indicates that the as-prepared SrZrO3 nanoparticles can be used as a promising photocatalyst in turning CO2 into value-added chemicals.