Jin Wonjoo, Go Hyunju, Jeong Juyeon, Park Jeonghwan, Tayyebi Ahmad, Yu Je Min, Kim Seungchul, Choi Keunsu, Jang Ji-Wook, Seo Kwanyong
School of Energy and Chemical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan, 44919, Republic of Korea.
Computational Science Research Center, Korea Institute of Science and Technology (KIST), Seoul, 02792, Republic of Korea.
Adv Mater. 2025 Sep;37(38):e2506567. doi: 10.1002/adma.202506567. Epub 2025 Jun 22.
The photoelectrochemical nitrate reduction reaction (PEC NORR) potentially converts nitrate, a major water pollutant, into NH, which is an eco-friendly, next-generation energy source. However, achieving high efficiency in the PEC NORR has been challenging because of the need for high applied voltage and competition with the hydrogen evolution reaction (HER). In this study, a PEC NORR is successfully implemented that demonstrated a high NH production rate of 2468 µg cm h (at -0.1 V vs RHE) using a c-Si photocathode with Ni foil as the catalyst. Conducting the PEC NORR under alkaline conditions can lead to the self-activation of the Ni surface with Ni(OH). Ni(OH) can suppress the competitive HER and facilitate NORR, enhancing NH production efficiency. Furthermore, a PEC NORR system is developed that operates without external voltage and achieved bias-free record-high solar to NH conversion efficiency of 3.8% and an NH production rate of 554 µg cm h.
光电化学硝酸盐还原反应（PEC NORR）有可能将主要的水污染物硝酸盐转化为氨，氨是一种环保的下一代能源。然而，由于需要高外加电压以及与析氢反应（HER）存在竞争，要在PEC NORR中实现高效率一直具有挑战性。在本研究中，成功实施了一种PEC NORR，使用以镍箔为催化剂的c-Si光电阴极，在-0.1 V（相对于可逆氢电极）时显示出2468 μg cm⁻² h⁻¹的高氨产率。在碱性条件下进行PEC NORR会导致镍表面与氢氧化镍发生自活化。氢氧化镍可以抑制竞争性的HER并促进NORR，提高氨的生产效率。此外，还开发了一种无需外部电压运行的PEC NORR系统，实现了无偏压下创纪录的3.8%的太阳能到氨的转换效率和554 μg cm⁻² h⁻¹的氨产率。
