State Key Laboratory of Urban Water Resource and Environment, School of Civil and Environmental Engineering, Harbin Institute of Technology, Shenzhen, Shenzhen 518055, China.
Environ Sci Technol. 2024 Oct 15;58(41):18202-18212. doi: 10.1021/acs.est.4c05395. Epub 2024 Oct 1.
Water electrolysis for green H production traditionally requires a stable supply of renewable electricity and pure water. However, spatial separation of renewables and water resources as well as water scarcity per capita in China necessitate unconventional water resources for electrolysis. Reclaimed water produced from municipal wastewater treatment plants is widely distributed with quality improved significantly in recent years, which may be a promising alternative to feedstock. However, there are few reports on the direct use of this wastewater for H production. Here, we present a direct electrolysis of reclaimed water for decentralized H production by developing a highly efficient and stable bifunctional 3D-dandelion-like (DL) vanadium(V)-doped CoP catalyst grown on Ni foam (NF) in an alkaline electrolyzer. The V-CoP-DL/NF electrode decreases 6.5 and 25% overpotentials of the hydrogen evolution reaction (HER) and oxygen evolution reaction (OER), respectively, compared to noble-metal Pt (HER) and IrO (OER) catalysts, and exhibits exceptional durability, as a voltage required for overall reclaimed water splitting only increases by 80 mV (1.81-1.89 V) after 90 days of operation at a current density of 10 mA cm. The maximum stable current can reach 1000 mA cm. The impacts of potential pollutants in reclaimed water on the performance of electrolysis and the behavior of major wastewater ions in alkaline electrolyte were investigated. The observed exceptional performance is attributed to the catalyst's unique nanostructure, which enhances charge transfer and reactant/electrolyte diffusion. The growth strategy further enhances the conductivity and stability of the catalyst. This work underscores the feasibility of utilizing reclaimed water instead of pure water as the feedstock for sustainable hydrogen production.
传统上，水的电解用于绿色 H 的生产需要稳定的可再生电力和纯水供应。然而，中国可再生能源和水资源的空间分离以及人均水资源短缺，需要非常规水资源用于电解。近年来，从城市污水处理厂生产的再生水分布广泛，水质得到了显著改善，这可能是一种有前途的原料替代品。然而，直接使用这种废水生产 H 的报道很少。在这里，我们通过在碱性电解质中开发高效稳定的三维蒲公英状（DL）钒（V）掺杂 CoP 催化剂，在 Ni 泡沫（NF）上生长，直接利用再生水进行分布式 H 的生产。与贵金属 Pt（HER）和 IrO（OER）催化剂相比，V-CoP-DL/NF 电极分别降低了析氢反应（HER）和析氧反应（OER）的 6.5%和 25%的过电势，并且具有出色的耐久性，在电流密度为 10 mA cm 时，总再生水分解所需的电压仅增加 80 mV（1.81-1.89 V），经过 90 天的运行。最大稳定电流可达 1000 mA cm。研究了再生水中潜在污染物对电解性能的影响以及主要废水离子在碱性电解质中的行为。观察到的优异性能归因于催化剂独特的纳米结构，它增强了电荷转移和反应物/电解质的扩散。生长策略进一步提高了催化剂的导电性和稳定性。这项工作强调了利用再生水代替纯水作为可持续制氢原料的可行性。
