Mutuma Bridget K, Mathebula Xiluva, Nongwe Isaac, Mtolo Bonakele P, Matsoso Boitumelo J, Erasmus Rudolph, Tetana Zikhona, Coville Neil J
DSI-NRF Centre of Excellence in Strong Materials and Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, WITS 2050, Johannesburg, South Africa.
Department of Natural Resources and Materials, Botswana Institute for Technology Research and Innovation, 50654 Machel Drive, Gaborone, Botswana.
Beilstein J Nanotechnol. 2020 Dec 9;11:1834-1846. doi: 10.3762/bjnano.11.165. eCollection 2020.
Core-shell based nanostructures are attractive candidates for photocatalysis owing to their tunable physicochemical properties, their interfacial contact effects, and their efficacy in charge-carrier separation. This study reports, for the first time, on the synthesis of mesoporous silica@nickel phyllosilicate/titania (mSiO@NiPS/TiO) core-shell nanostructures. The TEM results showed that the mSiO@NiPS composite has a core-shell nanostructure with a unique flake-like shell morphology. XPS analysis revealed the successful formation of 1:1 nickel phyllosilicate on the SiO surface. The addition of TiO to the mSiO@NiPS yielded the mSiO@NiPS/TiO composite. The bandgap energy of mSiO@NiPS and of mSiO@NiPS/TiO were estimated to be 2.05 and 2.68 eV, respectively, indicating the role of titania in tuning the optoelectronic properties of the SiO@nickel phyllosilicate. As a proof of concept, the core-shell nanostructures were used as photocatalysts for the degradation of methyl violet dye and the degradation efficiencies were found to be 72% and 99% for the mSiO@NiPS and the mSiO@NiPS/TiO nanostructures, respectively. Furthermore, a recyclability test revealed good stability and recyclability of the mSiO@NiPS/TiO photocatalyst with a degradation efficacy of 93% after three cycles. The porous flake-like morphology of the nickel phyllosilicate acted as a suitable support for the TiO nanoparticles. Further, a coating of TiO on the mSiO@NiPS surface greatly affected the surface features and optoelectronic properties of the core-shell nanostructure and yielded superior photocatalytic properties.
基于核壳结构的纳米材料因其可调谐的物理化学性质、界面接触效应以及在电荷载流子分离方面的功效，成为光催化领域颇具吸引力的候选材料。本研究首次报道了介孔二氧化硅@镍层状硅酸盐/二氧化钛（mSiO@NiPS/TiO）核壳纳米结构的合成。透射电子显微镜（TEM）结果表明，mSiO@NiPS复合材料具有核壳纳米结构，其壳层呈现独特的片状形态。X射线光电子能谱（XPS）分析表明，在SiO表面成功形成了1:1的镍层状硅酸盐。向mSiO@NiPS中添加TiO得到了mSiO@NiPS/TiO复合材料。据估计，mSiO@NiPS和mSiO@NiPS/TiO的带隙能量分别为2.
