Ni/Zn/Cr系复合金属氧化物的制备及其光催化还原二氧化碳性能研究

Preparation and Photocatalytic CO_2 Reduction Activity of Ni /Zn /Cr Composite Metal Oxides

以共沉淀法合成的Ni/Zn/Cr系层状金属氢氧化物(LDHs)经不同温度焙烧获得相应的复合金属氧化物,利用XRD、TG、XPS、TEM、BET和UV-Vis等表征手段对所制备样品的结构、组成、形貌以及吸光特性等进行了分析,并考察了样品在常温常压下光催化还原CO2(g)+H2O(g)的性能.结果表明,以Ni/Zn/Cr-LDHs为前驱体经5 00℃焙烧后可得到晶粒尺寸小、分散均匀度高的多相复合金属氧化物,主晶相为纳米尺度的NiO、Cr2O3、ZnCr2O4和NiCr2O4,在这些金属氧化物的协同作用下,样品表现出较好的光催化还原二氧化碳活性,主产物为CH4和CO.

A series of metal oxides complex were obtained by annealing co-precipitation-method-synthesized Ni /Zn /Cr layered double hydroxides( LDHs) at different temperature. The structure,composition,morphology and absorption properties of the samples were characterized by XRD,TG,XPS,TEM,BET and UV-Vis. Their activities in photocatalytic reduction of CO2with H2O vapor were tested at room temperature and atmospheric pressure. The results revealed that the sample calcined at 500 ℃ possessed the highest catalytic activity with CH4and CO as the major products,which was attributed to the interaction of uniformly dispersed NiO,Cr2O3,ZnCr2O4and NiCr2O4with small grain size.