Nitrate induced precise atom substitution and vacancies for overall water splitting

The accurate identification and manipulation for synergistic atom substitution and vacancy is significant and challenging for the overall water splitting (OWS) and theoretical analysis. Herein, a unique Co(OH)(NO3) (CoNH) material has been adopted to instantaneously realize oriented atom substitution and vacancies generation through fast impregnation. We found that in alkaline solution, the nitrate groups are prone to dissolve, thus forming nitrate vacancies that are the preferential sites for foreign atoms. Therefore, the controlled atom substitutional doping and vacancies can be simultaneously accomplished. As verification, after dipping in respective solution, S/Se/Mo/P was doped and nitrate deficiencies formed. The atom replacement and vacancy synergistically modulate the electron arrangement, chemical environment, and adsorption capability of host materials, thus boosting electrocatalytic OWS activity. In addition, the precise structure with definite lattice is propitious for the reveal of the structure–property connection. By theory calculation, the optimized electronic structure and adsorption ability of well-defined structures are also uncovered. This present work is expected to shed fresh light on accurate atom incorporation and vacancy engineering, thus achieving a deeper understanding of the structure-composition-property relationship.