RuO_2/ZrO_2/TaON复合光催化材料的制备及光解水制氢性能

Preparation of RuO_2/ZrO_2/TaON Composite Photocatalyst and Its Photocatalytic Properties for Water Splitting Hydrogen Evolution

采用控制水解法制备了细颗粒的Zr O2/Ta2O5复合氧化物粉体,在氨气流量为90 m L/min、850℃下氮化10 h获得Zr O2/Ta ON,用浸渍法制备含助催化剂Ru O2的复合光催化剂。用XRD、SEM、TEM和UV-Vis漫反射光谱等对所制备的光催化材料进行了表征,Zr O2、Ru O2的晶粒尺寸约为10 nm,Ta ON的晶粒尺寸约为25 nm,复合光催化剂可以吸收波长≤500 nm的可见光。Zr O2的引入降低了氮化生成Ta ON的缺陷密度,提高了Ta ON的比表面积。光电流及光催化分解水制氢反应定量评价了复合材料的光催化性能,Ru O2含量为2.0wt%时复合光催化剂活性最高,0.6 V偏压下光电流密度为0.6 m A/cm2,产氢速率为6.0?mol/h。

ZrO2/Ta2O5 composite oxide powders in a fine particle size were prepared by the controlled hydrolysis method, and subsequently nitrided in a flowing ammonia at a flow rate of 90 m L/min at 850℃ for 10 h, to form Zr O2/Ta ON. Then, Ru O2 co-catalyst was immobilized on the Zr O2/Ta ON via an impregnation method. The samples were characterized with XRD, SEM, TEM and UV-Vis diffuse reflectance spectroscope. Both Zr O2 and Ru O2 were in a crystallite size of ca. 10 nm, while Ta ON was in a crystallite size of ca. 25 nm, and composite photocatalysts absorbed the visible light at wavelength less than 500 nm. The introducing of Zr O2 reduced the defect density of Ta ON and increased the specific surface area of Ta ON. The photocatalytic efficiency of composite photocatalysts was quantitatively evaluated via determining the photo-current density as well as in the water splitting hydrogen evolution reaction. The sample with a Ru O2 loading of 2.0wt% showed the photocurrent of 0.6 m A/cm^2 at a bias voltage of 0.6 V, and H2 evolution rate as high as 6.0 μmol/h under a Xe lamp irradiation.