Hierarchically porous monoliths based on low-valence transition metal (Cu, Co, Mn) oxides: gelation and phase separation

• 来源期刊: 国家科学评论（英文版）
• 年，卷（期）: 2020,（11）
• 所属期刊栏目: Special Topic:Hierarchically Porous Materials
• 页码范围: 1656-1666
• 页数: 11页
• 语种: 英文
• DOI: 10.1093/nsr/nwaa103

摘要

Hierarchically porous monoliths based on copper (Cu),cobalt (Co) and manganese (Mn) oxides with three-dimensionally (3D) interconnected macropores and open nanopores were prepared using metal bromides as precursors via a sol-gel process accompanied by phase separation.The difficulty ofgelation for low-valence metal cation was overcome by introducing a highly electronegative Br atom near to the metal atom to control the rates of hydrolysis and polycondensation.The 3D interconnected macropores were obtained using appropriate polymers to induce phase separation.The domain sizes of macropores and skeletons can be controlled by reaction parameters such as concentration and/or average molecular weight of polymers,and the amount of hydrochloric acid.The crystalline metal oxide monoliths with their 3D interconnected macroporous structure preserved were obtained after heat treatment in air.