Natural reed leaves derived nickel-cobalt silicate hydroxides with phosphate modification enabling efficient oxygen evolution electrocatalysis

Developing efficient earth-abundant electrocatalysts for oxygen evolution reaction (OER) is of great significance to meet the satisfactory energy conversion efficiency of water electrolysis. Cost-effective transition metal silicate hydroxides based on abundant silicon have emerged as potential OER catalysts to realize the affordable hydrogen production. Herein, the hierarchical architectures of nickel-cobalt silicate hydroxides (NCS) have been synthesized using reed leave-derived silica as a natural silicon source. The boosted OER performances of hierarchical NCS architectures are achieved by introducing the surface phosphate modification. Benefiting from the favorable structure reconstruction regulated by electron-rich phosphate anion, the optimal NCS-P sample exhibits the remarkably enhanced OER activity with a minimum overpotential of 385 mV at current density of 10 mA cm-2 and a maximal mass activity of 57.6 A g-1 at a potential of 1.65 V vs RHE, which are 93 mV lower than and 7.2fold as high as those of pristine NCS, respectively. This study provides a new avenue to boost electrocatalytic performance through surface phosphate modification combined with abundant natural biomass resources.