Overall　water　splitting　is　an　effective　strategy　for　converting　solar　or　electrical　energy　into　clean　hydrogen　energy.　However,　the　sluggish　kinetics　of　the　oxygen　evolution　reaction　(OER)　within　the　water-splitting　process　acts　as　a　constraint　on　the　overall　efficiency　of　energy　transformation.　In　this　study,　single-metal　atom　(Fe,　Co,　and　Ni)　and　the　corresponding　bimetallic　atoms　were　loaded　onto　the　(100)　planes　of　poly(triazine　imide)　intercalated　with　lithium　chloride　through　metal-support　interactions　(MSI)　and　constructed　hydroxyl-modified　catalysts.　We　examined　the　OER　process　on　both　pristine　and　hydroxyl-modified　catalyst　surfaces,　and　the　results　demonstrated　that　the　hydroxyl-modified　catalysts　had　significantly　greater　catalytic　activity　for　OER　compared　to　the　pristine　surfaces.　The　conclusion　drawn　is　that　hydroxylation　alters　the　electronic　structure　of　the　catalysts,　thereby　enhancing　their　OER　activity.　This　study　has　deepened　our　understanding　of　the　role　of　hydroxyl　groups　in　the　catalytic　process　and　has　provided　a　viable　approach　for　developing　efficient　OER　catalysts　for　effective　water　splitting.　©　2025　Elsevier　Inc.