Silicon Nanowire Photocathodes for Photoelectrochemical Hydrogen Production

Abstract

The performance of silicon for water oxidation and hydrogen production can be improved by exploiting the antireflective properties of nanostructured silicon substrates. In this work, silicon nanowires were fabricated by metal-assisted electroless etching of silicon. An enhanced photocurrent density of −17 mA/cm2 was observed for the silicon nanowires coated with an iron sulphur carbonyl catalyst when compared to bare silicon nanowires (−5 mA/cm2). A substantial amount of 315 µmol/h hydrogen gas was produced at low bias potentials for the silicon nanowires coated with an iron sulphur carbonyl catalyst.

Morphology and Mechanical Properties of Fossil Diatom Frustules from Genera of Ellerbeckia and Melosira

“…Natural materials are evolutionary optimized materials that frequently feature hierarchical structures. They play an important role in bionanotechnology and composite materials [ 1 , 2 , 3 , 4 , 5 , 6 , 7 ]. Diatom biosilica is one of these biological materials, mainly from two sources: diatomaceous earth and living diatoms.…”

Kinetics of Hydrogen Generation from Oxidation of Hydrogenated Silicon Nanocrystals in Aqueous Solutions

“…Silicon nanostructures have also been considered as good candidates for photoelectrochemical and photocatalytic water splitting to produce hydrogen. Photo-electrodes based on arrays of silicon nanowires coupled with different catalysts [ 58 , 59 , 60 ], as well as porous silicon structures [ 61 , 62 , 63 ], were used for the generation of hydrogen. The surface modification of silicon nanostructures plays a considerable role in designing materials for solar-driven catalysis.…”

Mapping Free-Carriers in Multijunction Silicon Nanowires Using Infrared Near-Field Optical Microscopy

“…Semiconducting nanowires (NWs) have the potential to act as building blocks for a variety of electronic, − photonic, − photoelectrochemical, , and photovoltaic devices. − Silicon nanowires (SiNWs) are particularly interesting due to the extensive literature on the electronic and optical properties of bulk silicon and compatibility with existing processes and architectures. NWs are made by both top-down , and bottom-up ,,− , approaches but bottom-up approaches such as the vapor–liquid–solid (VLS) method allow for a greater degree of compositional control on the nanometer scale. ,, Dopants can be introduced during VLS growth by changing the vapor-phase composition, modifying the local electronic properties and encoding a wide range of functionality. ,, However, a reservoir effect, in which dopant atoms remain dissolved in the liquid catalyst after the gas-phase dopant is removed, can occur under certain growth conditions. − This leads to a broadening of the junctions, specifically when the dopant flow is turned off, that can negatively impact device performance. Additionally, discrepancies between reaction stoichiometry, dopant incorporation, and activation at high doping levels, − inhomogeneous dopant distribution, and diameter-dependent mobility effects complicate NW design and synthesis.…”

“…S emiconducting nanowires (NWs) have the potential to act as building blocks for a variety of electronic, 1−3 photonic, 4−9 photoelectrochemical, 10,11 and photovoltaic devices. 12−14 Silicon nanowires (SiNWs) are particularly interesting due to the extensive literature on the electronic and optical properties of bulk silicon and compatibility with existing processes and architectures.…”

“…12−14 Silicon nanowires (SiNWs) are particularly interesting due to the extensive literature on the electronic and optical properties of bulk silicon and compatibility with existing processes and architectures. NWs are made by both topdown 11,13 and bottom-up 1,3,[6][7][8][9]14 approaches but bottom-up approaches such as the vapor−liquid−solid (VLS) method allow for a greater degree of compositional control on the nanometer scale. 2,15,16 Dopants can be introduced during VLS growth by changing the vapor-phase composition, modifying the local electronic properties and encoding a wide range of functionality.…”