tailieunhanh - Báo cáo hóa học: " Fabrication of CuO nanoparticle interlinked microsphere cages by solution method"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Fabrication of CuO nanoparticle interlinked microsphere cages by solution method | Nanoscale Res Lett 2007 2 107-111 DOI S11671-007-9039-7 NANO IDEAS Fabrication of CuO nanoparticle interlinked microsphere cages by solution method Jian Quan Qi Hu Yong Tian Long Tu Li Helen Lai Wah Chan Published online 3 February 2007 To the authors 2007 Abstract Here we report a very simple method to convert conventional CuO powders to nanoparticle interlinked microsphere cages by solution method. CuO is dissolved into aqueous ammonia and the solution is diluted by alcohol and dip coating onto a glass substrate. Drying at 80 C the nanostructures with bunchy nanoparticles of Cu OH 2 can be formed. After the substrate immerges into the solution and we vaporize the solution hollow microspheres can be formed onto the substrate. There are three phases in the as-prepared samples monoclinic tenorite CuO orthorhombic Cu OH 2 and monoclinic carbonatodi-amminecopper II Cu NH3 2CO3 . After annealing at 150 C the products convert to CuO completely. At annealing temperature above 350 C the hollow microspheres became nanoparticle interlinked cages. Keywords CuO Microsphere Narnoparticle Introduction Cupric oxide CuO has a monoclinic crystal structure. It has many interesting properties and received much research attention 1-18 . CuO is a p-type semiconductor in general with a narrow band gap eV 18 J. Q. Qi H L. T. Li Department of Materials Sciences and Engineering Tsinghua University Beijing 100084 China e-mail jianquanqi@ J. Q. Qi H. Y. Tian H. L. W. Chan Department of Applied Physics and Materials Research Center The Hong Kong Polytechnic University Hong Kong China 19 and hence is potentially useful for constructing junction devices such as p-n junction diodes 20 . Recent studies indicate that CuO can exist in three different magnetic phases a three-dimensional collinear antiferromagnetic phase at temperatures under 213 K an intermediate noncollinear incommensurate magnetic phase between 213 and 230 K and a onedimensional quantum .