Alumina-Supported CoPS Nanostructures Derived from LDH as Highly Active Bifunctional Catalysts for Overall Water Splitting

It is highly desirable to develop efficient and low-cost electrocatalysts to boost the water-splitting reaction, which has been regarded as one of the ideal methods for commercial hydrogen production. Herein, the ultrathin amorphous Al2O3 nanosheets decorated with CoPS nano particles (size: 4-12 nm) were successfully synthesized using a CoAl-layered double hydroxide (CoAl-LDH) as precursor. The as-prepared catalysts exhibit low onset overpotential of 67 mV for the hydrogen evolution reaction and 250 mV for the oxygen evolution reaction together with good stability in an alkaline medium. Moreover, employed as the bifunctional electrocatalysts with a two-electrode electrolyzer, the CoPS nanostructure also produced a small cell voltage of 1.75 V to attain 10 mA cm(-2). The excellent electrocatalytic performance could be attributed not only to the high electron-donating and electron-accepting characters of P2- ligands and Co3+ ions, respectively, but also to the large active surface area and porous structure of the sample. This study introduces a new method for synthesizing ultrathin LDH nanosheets and provides a promising candidate toward highly active electrocatalysts for overall water splitting.