1. Orthorhombic NiSe2 Nanocrystals on Si Nanowires for Efficient Photoelectrochemical Water Splitting
- Author
-
Jeunghee Park, Suyoung Lee, Yoon Myung, Eun Hee Cha, Ik Seon Kwon, Seunghwan Cha, In Hye Kwak, Soo A Lim, Kidong Park, and Jaemin Seo
- Subjects
Photocurrent ,Materials science ,Hexagonal phase ,Nanowire ,Nickel selenide ,02 engineering and technology ,Photoelectrochemical cell ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,Water splitting ,General Materials Science ,Orthorhombic crystal system ,0210 nano-technology ,Photocatalytic water splitting - Abstract
Photocatalytic water splitting is a vital technology for clean renewable energy. Despite enormous progress, the search for earth-abundant photocatalysts with long-term stability and high catalytic activity is still an important issue. We report three possible polymorphs of nickel selenide (orthorhombic phase NiSe2, cubic phase NiSe2, and hexagonal phase NiSe) as bifunctional catalysts for water-splitting photoelectrochemical (PEC) cells. Photocathodes or photoanodes were fabricated by depositing the nickel selenide nanocrystals (NCs) onto p- or n-type Si nanowire arrays. Detailed structural analysis reveals that compared to the other two types, the orthorhombic NiSe2 NCs are more metallic and form less surface oxides. As a result, the orthorhombic NiSe2 NCs significantly enhanced the performance of water-splitting PEC cells by increasing the photocurrents and shifting the onset potentials. The high photocurrent is ascribed to the excellent catalytic activity toward water splitting, resulting in a low char... more...
- Published
- 2018
- Full Text
- View/download PDF