Mercury　is　a　poisonous　heavy　metal　element　capable　of　accumulating　within　the　human　body,　ultimately　resulting　in　chronic　poisoning.　To　mitigate　the　harm,　there　is　an　urgent　need　for　effective　mercury　adsorbents.　Herein,　we　propose　a　MOFs-functionalized　sulfhydryl　leather　collagen　fiber　composite　for　Hg(II)　capture,　which　was　innovatively　synthesized　by　grafting　2-aminoethanethiol　and　loading　ZIF-7-NH2　onto　sustainable　collagen　fiber　(CF).　The　acquired　CF-SH-Z7N　showed　an　efficient　Hg(II)　removal　rate　reaching　99.64　%　within　30　minutes　with　a　notable　initial　adsorption　rate　(h=k2qe2)　of　367.42　mg　g−1　min−1　at　a　Hg(II)　concentration　of　200　mg　L−1,　and　followed　the　pseudo-second-order　model　well.　It　additionally　exhibited　an　outstanding　adsorption　capacity,　reaching　1039.23　mg　g−1　as　well　as　an　ultra-high　selectivity(KdHg/KdM)　ranging　from　379　to　1046　over　Mg(II),　Ca(II),　K(I),　Cd(II)　and　Mn(II).　These　exceptional　performances　could　be　attributed　to　the　chelation　by　the　high　density　of　adsorption　sites　including　N,　O　and　S　and　the　ion-exchange　between　Zn(II)　and　Hg(II).　This　study　successfully　developed　a　highly　efficient　mercury　adsorbent　based　on　sustainable　leather　collagen　fibers,　which　achieved　a　win-win　situation.　©　2025　The　Institution　of　Chemical　Engineers