Tailored NiO_x/Ni Cocatalysts on Silicon for Highly Efficient Water Splitting Photoanodes via Pulsed Electrodeposition

Abstract

Converting solar energy by photoelectrochemical water splitting has been regarded as a promising way to resolve the global energy crisis and alleviate environmental pollution. Silicon, which is earth-abundant and has a narrow band gap, is an attractive material for photoelectrochemical water splitting. However, Si-based photoelectrodes suffer from photocorrosion, which leads to instability in electrolytes and high overpotential. Herein, we have fabricated a metal–insulator–semiconductor structure of NiO x /Ni/n-Si photoanodes for highly efficient water splitting. NiO x /Ni nanoparticles, which act as well-known oxygen evolution catalysts, are deposited on the surface of silicon by facile pulsed electrodeposition. Light absorption and catalytic activity are greatly affected by the coverage of Ni nanoparticles, and the highly efficient NiO x /Ni catalyst structure is induced by simple annealing. The NiO x /Ni nanoparticles show highly enhanced charge separation and transport efficiency, which are vital factors for photoelectrochemical water splitting, leading to ∼100% Faradaic efficiency and incident photon-to-current efficiency. A low onset potential of 1.08 V versus a reversible hydrogen electrode for 1 mA/cm2 and a high photocurrent density of 14.7 mA/cm2 at 1.23 V are obtained.

Electrodeposition of (hydro)oxides for an oxygen evolution electrode

“…Many advanced bimetallic (hydro)oxide OER electrocatalysts based on Ni(OH) 2 and Co 3 O 4 have been explored via electrodeposition. [32][33][34][35] In this minireview, we focus on the recent discoveries of electrode preparation and OER applications of (hydro)oxides using the electrodeposition technique.…”

“…In principle, a synthetic method capable of producing ne grains can be used to produce nanomaterials. In the past few years, a number of important advances have been made in the electrodeposition of metal oxide nanoparticles such as NiO, 33 43,78 Electrodeposition involves the deposition of ions on to an electrode surface in an electrolyte via electrochemical reactions using direct current or pulsed electric elds. In order to obtain nanomaterials, the nucleation rate needs to be increased and the growth rate decreased.…”

Strategies for Semiconductor/Electrocatalyst Coupling toward Solar‐Driven Water Splitting

“…Copyright 2015, The American Chemical Society. f) The potential‐time curve of pulsed electrodeposition of Ni . g) The PEC performance of different Ni‐modified n‐Si photoanodes.…”

Dissociating Water at n‐Si Photoanodes Partially Covered with Fe Catalysts

“…Recent reports by our group, and others, have demonstrated that aqueous electrodeposition of transition metals nanoparticles (NPs) on n‐Si is effective to prepare inhomogeneous Si/metal Schottky junctions that can be further employed as stable Si‐based photoanodes without protection layer. This type of photoanode has been reported, so far, for n‐Si/Ni and n‐Si/Co junctions and it has been recently shown that the performance of these systems can be enhanced by using an additional catalytic shell, typically a hydroxide, or a metallic coating, over the NPs. To the best of our knowledge, this phenomenon has never been applied to n‐Si/Fe junctions so far, which we present for the first time in this article.…”