Kim Haseong, Bae Hyojung, Bang Seung Wan, Kim Seyoung, Lee Sang Hyun, Ryu Sang-Wan, Ha Jun-Seok
Opt Express. 2019 Feb 18;27(4):A206-A215. doi: 10.1364/OE.27.00A206.
Photoelectrochemical (PEC) water splitting is one of the most promising hydrogen production methods because of its high efficiency, renewable resources and harmless by-products. Gallium nitride (GaN) is suitable for PEC water splitting because it has excellent stability in electrolyte and band gap energy which straddles the redox potential of water (V = 1.23 V). These characteristics allow this material to split water stably without external bias. However, the stability of GaN is still not sufficient for practical applications. In this study, we investigated the properties of GaN photoelectrodes with aluminum oxide (AlO) thin film as a protection layer for increasing stability. In a long-term stability test, AlO-coated GaN showed more stable photocurrent than that of bare GaN. The total hydrogen production amount was also improved in AlO-coated samples than bare GaN. These results indicate that the AlO protection layer significantly enhances stability and hydrogen production.
光电化学（PEC）水分解是最具前景的制氢方法之一，因其效率高、资源可再生且副产物无害。氮化镓（GaN）适用于PEC水分解，因为它在电解质中具有出色的稳定性，且其带隙能量跨越水的氧化还原电位（V = 1.23 V）。这些特性使这种材料无需外部偏压就能稳定地分解水。然而，GaN的稳定性对于实际应用来说仍不够充分。在本研究中，我们研究了以氧化铝（AlO）薄膜作为保护层来提高稳定性的GaN光电极的性能。在长期稳定性测试中，涂覆AlO的GaN比裸GaN表现出更稳定的光电流。涂覆AlO的样品的总产氢量也比裸GaN有所提高。这些结果表明，AlO保护层显著提高了稳定性和产氢量。
