Khemthong Pongtanawat, Kongmark Chanapa, Kochaputi Nopparuj, Mahakot Sompin, Rodporn Somboonsup, Faungnawakij Kajornsak
National Science and Technology Development Agency (NSTDA) , National Nanotechnology Center (NANOTEC) , Pathumthani 12120 , Thailand.
Synchrotron Light Research Institute (SLRI) , 111 University Avenue , Muang, Nakhon Ratchasima 30000 , Thailand.
Inorg Chem. 2019 May 20;58(10):6584-6587. doi: 10.1021/acs.inorgchem.9b00540. Epub 2019 May 1.
The thermal transformation of Cu(NO) and (Fe(NO) into a CuFeO spinel structure in the confined space of SBA-15 has been investigated. Interestingly, we observed the new formation mechanism of CuFeO in SBA-15 via isolated metal ions (Cu and Fe) surrounded by oxygen atoms, which gradually transformed to CuO and ferrihydrite. The latter evolved to maghemite spinel ferrite and reacted with CuO to form CuFeO as the final species. In contrast, in the nonconfined space where the spinel was produced via a sol-gel combustion method, the nanostructure of CuFeO immediately formed during the sol-gel combustion process and its crystallinity was improved after calcination. This is the first report on probing-phase formation using high-temperature in situ X-ray absorption fine structure.
研究了在SBA - 15的受限空间内Cu(NO)和(Fe(NO)热转变为CuFeO尖晶石结构的过程。有趣的是，我们观察到在SBA - 15中通过被氧原子包围的孤立金属离子（Cu和Fe）形成CuFeO的新机制，这些金属离子逐渐转变为CuO和水铁矿。后者演变成磁赤铁矿尖晶石铁氧体并与CuO反应形成最终产物CuFeO。相比之下，在通过溶胶 - 凝胶燃烧法制备尖晶石的非受限空间中，CuFeO的纳米结构在溶胶 - 凝胶燃烧过程中立即形成，并且在煅烧后其结晶度得到提高。这是首次使用高温原位X射线吸收精细结构探测相形成的报告。
