Carbon‐Doped Metal Oxide Nanoparticles Prepared from Metal Nitrates in Supercritical CO₂‐Enabled Polymer Nanoreactors

Abstract

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/ppsc.201900016. Various C-doped metal oxide nanoparticles (NPs) are prepared from metal nitrates in poly-(methyl vinyl ether-co-maleic anhydride) (PVM/MA) nanoreactors. The loading of metal nitrates in the nanoreactors is realized via a process of solution-enhanced dispersion by supercritical CO 2 . When the temperature exceeds the thermal decomposition temperature of the nitrates, the nitrates-loaded nanoreactors transform into C-doped metal oxide NPs. ZnO, NiO, and Co 3 O 4 NPs as representative of the doped oxides are successfully fabricated. A precise control over the doping concentration and doping site in the lattice is achieved by changing the mass ratio between PVM/MA and metal nitrate. The controllable carbon doping avoids undesirable aggregation of carbon species and metal oxide NPs, endows the NPs with broad and strong absorption bands in the visible light region, and creates channels for separation of photo-generated electrons and holes. In this regard, the resultant C-doped metal oxide NPs exhibit excellent photocatalytic, photo-induced antibacterial, and photothermal performances.

Role of supercritical carbon dioxide (scCO2) in fabrication of inorganic-based materials: a green and unique route

“…Incorporation of the non-metallic elements in many wide-band-gap metal oxides improves their intrinsic conductivities and creates a channel for separation of photo-generated electrons and hole. Owing to the ease of solubility of PVM/MA in acetone and its stable properties and non-reactivity with metal nitrates, Jiang and colleagues fabricated the multiple C-doped metal oxide nanoparticles via combining the SAS method with the thermal annealing of metal nitrates [ 64 ]. Initially, metal oxide precursors, such as Co(NO 3 ) 2 , Ni(NO 3 ) 2 , and Zn(NO 3 ) 2 were loaded in PVM/MA, resulting in the polymeric nanoreactors.…”