Hydrogen production using metal nanoparticle modified silicon thin film photoelectrode

Abstract

Hydrogen production using water splitting by photoelectrochemical solar cells equipped with a TiO 2 photoelectrode has been attracting much attention. However, TiO 2 encounters serious difficulty in achieving hydrogen evolution. One solution to this difficulty is using a hydrogen-producing semiconductor, such as silicon, and an oxidation reaction other than oxygen evolution, such as oxidation of iodide ions into iodine (triiodide ion). In this study, microcrystalline silicon (µc-Si:H) thin films are used as photoelectrodes in the photodecomposition of HI for low-cost and efficient production of solar hydrogen. An n-µc-3C-SiC:H and an i-µc-Si:H layer are deposited on glassy carbon substrates using the hot-wire cat-CVD method. The µc-Si:H electrodes are modified with platinum nanoparticles through electroless displacement deposition. The platinum nanoparticles improve the electrode's stability and catalytic activity. The electrodes produce hydrogen gas and iodine via photoelectrochemical decomposition of HI with no external bias under simulated solar illumination. We also attempt solar water splitting using a multi-photon system equipped with the µc-Si:H thin film and TiO 2 photoelectrodes in series.

Oxidatively Stable Nanoporous Silicon Photocathodes with Enhanced Onset Voltage for Photoelectrochemical Proton Reduction

“…It is well-known that Pt NPs deposited onto Si can lower the kinetic barrier for proton reduction. ,,− We also find that electroless deposition of Pt NPs onto a fresh planar Si electrode provides a H 2 -production J – V curve with a steeper rise in photocurrent magnitude at increasingly negative bias potential compared with bare pl-Si (Figure S2A; cf. Figure A).…”

Catalytic nanopores for electroless deposition of adhesive metal films on silicon: Applications to various silicon substrates including multi‐ and micro‐crystalline

“…1 Ω cm and whose planes were (100), (111), and (110); p-type (100) wafers whose resistibility was ca. 0.01 and 10 Ω cm; multicrystalline n-type wafers; and hydrogenated microcrystalline i-type/n-type thin films deposited on glassy carbon substrates by the hot-wire cat-CVD method [17,18]. Single-crystalline Si wafers were cut into 2 x 3 cm pieces.…”