High Stability and Efficiency of GaN Photocatalyst for Hydrogen Generation from Water

Abstract

Continuous hydrogen generation from water was realized for 110 h using an n-type GaN film with a NiO cocatalyst. This GaN–NiO photocatalyst exhibits incident photon-to-current conversion efficiencies of 70 and 57% at wavelengths of 300 and 350 nm, respectively. These results indicate that the GaN–NiO photocatalyst has high stability and efficiency for hydrogen generation.

Effect of inserted Si p-n junction on GaN-based photo-electrochemical CO2 conversion system

“…NiO co-catalysts are also supported on the GaN in the same manner, as described in a previous report. 22 The structure of Si p-n junction is briefly outlined in Figure 1. [23][24][25] The p-i-n structure was manufactured by layered amorphous Si on the n-Si single-crystal substrate that converts the energy from light to electricity.…”

β-Ga2O3 Single Crystal as a Photoelectrode for Water Splitting

“…1,5,6) As for GaN single crystalline films, incident photon-to-current conversion efficiency (IPCE) reaches as high as 70% at 300 nm, which is much higher than those of powder photocatalysts. 7) Therefore, the use of single crystals enables the suppression of the influences of defects and grain boundaries and thus the evaluation of the intrinsic photoelectrodes properties. Moreover, sophisticated techniques can be employed to modify not only surface reaction sites (surface orientation, atomically regulated steps, and facets) but also the bulk properties in a fashion of semiconductor engineering (such as controlling the potential profile in heterostructures).…”

Thin-Film Materials for the Protection of Semiconducting Photoelectrodes in Solar-Fuel Generators

“…106 n-GaN showed improved stability in 1 M NaOH for up to 100 h using a surface-located NiO cocatalyst. 107,108 The relatively narrow band-gap metal oxide semiconductor, BiVO 4 , is only stable anodically at pH = ~7 in contact with electrochemically reversible redox couples. Consistently, BiVO 4 only lasts for a few cyclic voltammetric scans in pH > 13 before the material dissolves.…”