Hydrogen production via water electrolysis holds promising application prospects. However, the oxygen evolution reaction (OER) at the anode encounters a higher energy barrier and sluggish kinetics due to its four-electron coupling transfer mechanism. This makes OER as the rate-limiting step in water electrolysis. Consequently, the development of efficient and stable OER electrocatalysts has become an urgent need. In this study, a sulfur-doped lignin-derived carbon-encapsulated iron-nickel catalyst (FeNi@SC) was prepared through hydrothermal self-assembly and high-temperature carbonization pyrolysis. This non-precious metal catalyst exhibited exceptional OER activity and long-term stability in alkaline media. Specifically, FeNi@SC achieved a low overpotential of 216 mV at a current density of 10 mA·cm^–2, significantly lower than the commercial precious metal catalyst Ru/C (320 mV) , and demonstrated remarkable stability over 100 h. Experimental results reveal that the synergistic effect of FeNi bimetal and sulfur doping promotes the OER process. Moreover, the strong coordination between the lignin framework and metal ions, coupled with the protective carbon coating, effectively prevents the leaching and agglomeration of FeNi alloy during the reaction. Our findings may provide a promising approach for developing highly active and stable OER catalysts, and also offer a strategy for the valorization of lignin.

In this research, 66 Sentinel-1 images spanning from January 2018 to June 2023 were analyzed using Persistent Scatterer Interferometric (PSI) technology to map ground deformation in Fuzhou City. The accuracy of the results was demonstrated by cross-validation. The study reveals that the overall deformation rate in Fuzhou City ranges from –44~18 mm/yr, with five distinct regions experiencing significant ground subsidence. Among these, four regions are located near subway lines, and the maximum subsidence occurs at the intersection of Xiazhang Road and Fubei Road in Changle District. The occurrence of subsidence in Fuzhou is the consequence of a complex interplay between natural and anthropogenic factors. In terms of natural factors, the subsidence is primarily distributed in areas with Quaternary sediments. The anthropogenic factors primarily include construction activities such as subway construction, building construction and demolition, as well as changes in ground loading due to warehouse operations such as cargo loading and unloading. The study results can provide a reference basis for urban construction and prevention management of subsidence disasters in Fuzhou.