Article Title

On-demand production of hydrogen by reacting porous silicon nanowires with water

Authors

Rui Ning, Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
Yue Jiang, Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
Yitian Zeng, Department of Materials Science and Engineering, Stanford University, Stanford, CA 94305, USA
Huaxin Gong, Department of Chemical Engineering, Stanford University, Stanford, CA 94305, USA
Jiheng Zhao, Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
Jeffrey Weisse, Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
Xinjian Shi, Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
Thomas M. Gill, Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA
Xiaolin Zheng, Department of Mechanical Engineering, Stanford University, Stanford, CA 94305, USA

Keywords

silicon nanowire, porous silicon, hydrogen generation, metal-assisted anodic etching, metal-assisted chemical etching, water splitting

Abstract

On-demand hydrogen generation is desired for fuel cells, energy storage, and clean energy applications. Silicon nanowires (SiNWs) and nanoparticles (SiNPs) have been reported to generate hydrogen by reacting with water, but these processes usually require external assistance, such as light, electricity or catalysts. Herein, we demonstrate that a porous SiNWs array, which is fabricated via the metal-assisted anodic etching (MAAE) method, reacts with water under ambient and dark conditions without any energy inputs. The reaction between the SiNWs and water generates hydrogen at a rate that is about ten times faster than the reported rates of other Si nanostructures. Two possible sources of enhancement are discussed: SiNWs maintain their high specific surface area as they don’t agglomerate, and the intrinsic strain of the nanowires promotes the reactivity. Moreover, the porous SiNWs array is portable, reusable, and environmentally friendly, yielding a promising route to produce hydrogen in a distributed manner.

Graphical Abstract

DOI

https://doi.org/10.1007/s12274-020-2734-8

Publisher

Tsinghua University Press

Recommended Citation

Rui Ning,Yue Jiang,Yitian Zeng,Huaxin Gong,Jiheng Zhao,Jeffrey Weisse,Xinjian Shi,Thomas M. Gill,Xiaolin Zheng, On-demand production of hydrogen by reacting porous silicon nanowires with water. NanoRes.2020, 13(5): 1459–1464