合成工艺对钙钛矿型LaCo_(1-x)W_xO_3催化剂光催化性能的影响

Effect of Synthesis Process on the Photocatalytic Properties of Perovskite LaCo_(1-x)W_xO_3 Catalysts

用水热法合成了钴和钨同时作为活性组分的一系列三元金属复合氧化物LaCo_(1-x)W_xO_3(x=0.4、0.5、0.6、0.8、1.0),通过降解亚甲基蓝测试其光催化性能.设计单因素实验考察n(Co)/n(W)、水热时间、水热温度、煅烧温度等因素对催化剂光催化性能的影响.水热温度为180℃时制备的催化剂活性最高,温度过高会破坏催化剂的晶型,使催化剂活性下降.LaCo_(0.2)W_(0.8)表现出较高的可见光光催化活性,并且合成条件适中.使用XRD、SEM、TG-DSC、红外、比表面积测试等手段对LaCo_(0.2)W_(0.8)进行表征和测定,结果表明:水热过程中钙钛矿晶相已经基本形成,适当的n(Co)/n(W)使催化剂对可见光具有宽范围响应的同时,又能使其光生空穴具有较强的氧化能力,进而提高催化剂的可见光催化活性.

Photocatalysts LaCo1-xWxO3(x is 0.4,0.5,0.6,0.8,1.0)were synthesized with cobalt and tungsten as the active components by using hydrothermal method.The photocatalytic activities were tested by the degradation of methylene blue.The single factor experiment was designed to investigate the effect of the factors,such as Co/W mole ratio,hydrothermal time,hydrothermal temperature and calcination temperature on the photocatalytic activities of the catalysts.The catalytic activity of the catalysts exhibited the best performance when the hydrothermal temperature was 180℃.Higher temperature destroyed the crystal type and decreased the catalytic activity.LaCo0.2W0.8O3 showed higher visible light photocatalytic activity and the synthesis conditions are moderate.The photocatalyst LaCo0.2W0.8O3 was characterized by using XRD,SEM,TG-DSC,FT-IR,SSA analysis.The results showed that the perovskite phase has basically formed during the hydro-thermal process.The catalyst owing appropriate Co/W mole ratio has a wider range of response to visual light and the light hole with stronger oxidation ability,which improve catalytic activity of the catalysts response to the visible light.