RT Journal Article T1 Towards control of the size, composition and surface area of NiO nanostructures by Sn doping A1 Taeño González, María A1 Maestre Varea, David A1 Ramírez Castellanos, Julio A1 Li, Shaohui A1 Lee, Pooi See A1 Cremades Rodríguez, Ana Isabel AB 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. PB MDPI SN 2079-4991 YR 2021 FD 2021-02 LK https://hdl.handle.net/20.500.14352/7992 UL https://hdl.handle.net/20.500.14352/7992 LA eng NO © 2021 by the authors.Licensee MDPIThis research was funded by FEDER/M-ERA.Net Cofund projects: RTI2018-097195-B-I00 and PCIN-2017-106. NO Ministerio de Ciencia e Innovación (MICINN)/FEDER DS Docta Complutense RD 23 ago 2025