High-Performance Silicon Photoanode Using Nickel/Iron as Catalyst for Efficient Ethanol Oxidation Reaction

In this study, we report NiFe/ZrO₂/n-Si photoanodes with efficient photoelectrocatalytic activity for ethanol oxidation reaction (EOR) in alkaline medium (1.0 M KOH). NiFe/ZrO₂/n-Si electrode exhibits apparently improved EOR activity with the mass-specific activity of 34.4 mA·cm^–2 under visible light illumination, which is approximately 2.53 times higher than that in the dark (13.6 mA·cm^–2). NiFe/ZrO₂/n-Si electrode presents obviously enhanced stability under visible light illumination due to the acceleration of the oxidation of intermediate products adsorbed on the surface of the catalyst. Additionally, NiFe/ZrO₂/n-Si photoanode displays better EOR activity compared with Pt­(Pd)/ZrO₂/n-Si photoanodes, which shows the potential to replace the Pt or Pd in EOR using a silicon photoanode

High-Performance Silicon Photoanode Enhanced by Gold Nanoparticles for Efficient Water Oxidation

Ni catalyst is a low-cost catalyst for oxygen evolution reaction (OER) on silicon metal–insulator–semiconductor photoanode. We found that Au nanoparticles incorporated with Ni nanoparticles can enhance the OER activity and stability of Ni nanoparticles due to the local surface plasmon resonance (LSPR) effect of the Au nanoparticles. The efficiency of NiAu/TiO₂/n-Si photoanode can be boosted at least three times under the illumination (100 mW/cm²) by LSPR effect of the Au nanoparticles. A small onset potential of 1.03 V versus reversible hydrogen electrode (overpotential, η₀ = −0.20 V) and a current density of 18.80 mA/cm² at 1.23 V versus reversible hydrogen electrode can be obtained. The NiAu/TiO₂/n-Si photoanode exhibits a high saturation current density of 35 mA/cm², which is greater than that of most of the state-of-the-art silicon photoanodes