%0 Journal Article
%A Taeño González, María
%A Maestre Varea, David
%A Ramírez Castellanos, Julio
%A Li, Shaohui
%A Lee, Pooi See
%A Cremades Rodríguez, Ana Isabel
%T Towards control of the size, composition and surface area of NiO nanostructures by Sn doping
%D 2021
%@ 2079-4991
%U https://hdl.handle.net/20.500.14352/7992
%X Achieving nanostructures with high surface area is one of the most challenging tasks as this metric usually plays a key role in technological applications, such as energy storage, gas sensing or photocatalysis, fields in which NiO is gaining increasing attention recently. Furthermore, the advent of modern NiO-based devices can take advantage of a deeper knowledge of the doping process in NiO, and the fabrication of p-n heterojunctions. By controlling experimental conditions such as dopant concentration, reaction time, temperature or pH, NiO morphology and doping mechanisms can be modulated. In this work, undoped and Sn doped nanoparticles and NiO/SnO_2 nanostructures with high surface areas were obtained as a result of Sn incorporation. We demonstrate that Sn incorporation leads to the formation of nanosticks morphology, not previously observed for undoped NiO, promoting p-n heterostructures. Consequently, a surface area value around 340 m^2/g was obtained for NiO nanoparticles with 4.7 at.% of Sn, which is nearly nine times higher than that of undoped NiO. The presence of Sn with different oxidation states and variable Ni^(3+)/Ni^(2+) ratio as a function of the Sn content were also verified by XPS, suggesting a combination of two charge compensation mechanisms (electronic and ionic) for the substitution of Ni^(2+) by Sn^(4+). These results make Sn doped NiO nanostructures a potential candidate for a high number of technological applications, in which implementations can be achieved in the form of NiO-SnO_2 p-n heterostructures.
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