Cai Shengxiang, Ghasemian Mohammad B, Rahim Md Arifur, Baharfar Mahroo, Yang Jiong, Tang Jianbo, Kalantar-Zadeh Kourosh, Allioux Francois-Marie
School of Chemical Engineering, University of New South Wales (UNSW), Sydney, NSW 2052, Australia.
School of Chemical and Biomolecular Engineering, University of Sydney, Sydney, New South Wales 2006, Australia.
Nanoscale. 2023 Mar 2;15(9):4291-4300. doi: 10.1039/d2nr06384k.
Gallium (Ga) is a low melting point post-transition metal that, under mild mechanical agitation, can form micron and submicron-sized particles with combined fluid-like and metallic properties. In this work, an inorganic network of Ga liquid metal particles was synthesised spontaneous formation of manganese (Mn) oxide species on their liquid metallic surfaces forming an all-inorganic composite. The micron-sized Ga particles formed by sonication were connected together by Mn oxide nanostructures spontaneously established from the reduction of a Mn salt in aqueous solution slightly above the melting point of Ga. The formed Mn oxide nanostructures were found to coalesce from the surface of the Ga particles into a continuous inorganic network. The morphology of the composites could be altered by varying the Mn salt concentration and by performing post-treatment annealing. The composites presented a shell of various Mn oxide nanostructures including wrinkled sheets, rods and nanoneedles, around spherical liquid Ga particles, and a liquid metal core. The photoelectric and optical properties of the composites were thoroughly characterised, which revealed decreasing bandgaps and valence band edge characteristics as a function of increased Mn oxide coverage. The photoluminescence properties of the composites could be also engineered by increasing the Mn oxide coverage. The all-inorganic liquid Ga composite could be formed a straightforward reduction reaction of a Mn-rich salt at the surface of liquid Ga particles with tunable surface properties for future optoelectronic applications.
镓（Ga）是一种低熔点的后过渡金属，在温和的机械搅拌下，它可以形成具有类似流体和金属特性的微米级和亚微米级颗粒。在这项工作中，合成了一种由镓液态金属颗粒组成的无机网络，通过在其液态金属表面自发形成锰（Mn）氧化物物种，形成了一种全无机复合材料。通过超声处理形成的微米级镓颗粒通过在略高于镓熔点的水溶液中由锰盐还原自发形成的氧化锰纳米结构连接在一起。发现形成的氧化锰纳米结构从镓颗粒表面聚结形成一个连续的无机网络。通过改变锰盐浓度和进行后处理退火可以改变复合材料的形态。复合材料呈现出围绕球形液态镓颗粒的各种氧化锰纳米结构（包括褶皱片、棒和纳米针）的外壳以及一个液态金属核心。对复合材料的光电和光学性质进行了全面表征，结果表明，随着氧化锰覆盖率的增加，带隙和价带边缘特性降低。通过增加氧化锰覆盖率也可以调控复合材料的光致发光性质。这种全无机液态镓复合材料可以通过在液态镓颗粒表面对富锰盐进行直接还原反应形成，具有可调节的表面性质，可用于未来的光电子应用。
