A glass-ceramic with accelerated surface reconstruction toward the efficient oxygen evolution reaction.

The effective non-precious metal catalysts toward the oxygen evolution reaction (OER) are highly desirable for electrochemical water splitting. The amorphous electrocatalysts are highly potential due to the increased exposure of active sites, while the crystalline counterparts exhibit the superiority of electron transport to active sites. To organically integrate these two components, here we prepare a novel glass-ceramic (Ni 1.5 Sn@triMPO 4 ) by embedding crystalline Ni 1.5 Sn nanoparticles into amorphous trimetallic phosphate (triMPO 4 ) matrix. This unique crystalline-amorphous nanostructure synergistically accelerates the surface reconstruction to active Ni(Fe)OOH, due to the low vacancy formation energy of Sn in glass-ceramic and high adsorption energy of PO 4 3- at the V O sites. Compared to control samples, this dual-phase glass-ceramic after surface reconstruction exhibits a remarkably lowered overpotential and boosted OER kinetics, rivaling most of state-of-the-art electrocatalysts. Theoretical calculations reveal that the residual PO 4 3- and the V O sites induce electron depletion of adjacent Ni atoms and shift the d band center much closer to the Fermi level. Such redistribution of electron states optimizes the adsorption of OH* and OOH* intermediates on metal oxyhydroxides and promotes the OER activity. This study proves the structural superiority of glass-ceramics in boosting surface reconstruction and provides new insights into design of advanced electrocatalysts.