Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin 300350, China.
Shanxi Laboratory for Yellow River, College of Environment and Resource, Shanxi University, 92, Wucheng Rd., Shanxi 030006, China.
J Colloid Interface Sci. 2023 Oct;647:510-518. doi: 10.1016/j.jcis.2023.05.090. Epub 2023 May 18.
Heterostructure engineering is one of the most promising strategies for efficient water splitting by electrocatalysts. However, it remains challenging to design heterostructured catalysts to achieve the desired goals in both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) in seawater splitting. Here, particulate heterostructures of FeCoNi hydroxide/sulfide supported on nickel foams were prepared by hydrothermal methods to achieve a high-performance bifunctional catalyst. The synthesized FeCoNi hydroxide/sulfide exhibited excellent electrocatalytic performance, requiring an overpotential of 195 mV for OER and 76 mV for HER to achieve a current density of 10 mA cm while showing excellent stability. The catalyst maintains its excellent performance even in artificial or natural seawater with high salinity, which is a harsh environment. When applied directly to a water splitting system, the catalyst achieves a current density of 10 mA cm at only 1.5 V (1.57 V in alkaline seawater). The FeCoNi hydroxide/sulfide heterostructure is an excellent electrocatalytic bifunctional catalyst due to compositional modulation, systematic charge transfer optimization, improved intermediates adsorption, and increased electrocatalytic active sites and the synergistic effect of the heterostructure.
异质结构工程是电催化剂高效水分解最有前途的策略之一。然而，设计用于在海水电解中实现氢 Evolution 反应（HER）和氧 Evolution 反应（OER）期望目标的异质结构催化剂仍然具有挑战性。在这里，通过水热法制备了负载在泡沫镍上的 FeCoNi 氢氧化物/硫化物的颗粒异质结构，以实现高性能的双功能催化剂。合成的 FeCoNi 氢氧化物/硫化物表现出优异的电催化性能，在 10 mA cm 的电流密度下，OER 需要 195 mV 的过电势，HER 需要 76 mV 的过电势，并且具有出色的稳定性。该催化剂即使在高盐度的人工或天然海水中也能保持其优异的性能，这是一种恶劣的环境。当直接应用于水分解系统时，该催化剂仅在 1.5 V（碱性海水中为 1.57 V）时即可达到 10 mA cm 的电流密度。FeCoNi 氢氧化物/硫化物异质结构是一种优异的电催化双功能催化剂，这归因于组成调制、系统电荷转移优化、改进的中间体吸附以及增加的电催化活性位点和异质结构的协同效应。
