均匀沉淀法制备纳米氧化镍及其工艺优化

为研制生物质气化用纳米N iO催化剂,文中以六水合硝酸镍为原料、尿素为沉淀剂,采用均匀沉淀法制备了纳米N iO,并利用TGA,XRD,TEM等分析手段对前驱体和产品的性能进行了表征。同时,探讨了制备条件对产品粒径和产率的影响,得出了最佳工艺条件:反应物n(六水合硝酸镍)/n(尿素)=1∶3,沉淀反应温度和时间分别为115℃和2.5 h,煅烧温度400℃,煅烧时间1 h。最佳条件下所得纳米N iO粒子呈球形,分散性好,纯度较高,属立方晶系结构,平均粒径约为7.5 nm。

Preparation of NiO nanoparticles by homogeneous precipitation method at optimized process conditions

For the development of effective catalysts to be used in biomass gasification,NiO nanoparticles were prepared by a homogeneous precipitation method involving an aqueous solution of nickel nitrate hexahydrate and urea.Different approaches such as TGA,XRD and TEM were used to characterize the NiO nanoparticles and precursors.Meanwhile,the effects of various technical parameters in preparation process on the yield and mean size of the products were investigated,and the optimum conditions found for preparing NiO nanoparticles were as follows: the molar ratio of nickel nitrate hexahydrate to urea was 1∶3,the temperature and time of precipitation reaction were respectively 115 ℃ and 2.5 h,the temperature of calcination was 400 ℃ and the time of calcination was 1h.The NiO nanoparticles prepared under the optimum conditions were spherical in shape and well dispersed;they have high purity and a fine crystal phase of cubic syngony with a mean size of about 7.5 nm.