The construction of defect-rich CoP@CoP@(Co/Ni)2P triple-shell hollow nanospheres with boosted electrocatalytic hydrogen evolution performances over a wide pH range

The development of highly effective non-precious metal catalysts with high intrinsic activity and rich accessible catalysis centers are the relentless goals of the scientific community to lower energy consumption and production cost. In this work, a unique triple-shell CoP@CoP@(Co/Ni)2P hollow structure with rich defect structure has been successfully constructed, which presents remarkable activity against HER over a wide pH range. The overpotentials of 147 mV, 139 mV, and 144 mV are achieved at 10 mA cm-2 current density for CoP@CoP@(Co/ Ni)2P in 1 M KOH, 0.5 M H2SO4, and 1 M phosphate-buffered saline (PBS) conditions, respectively. The excellent HER activity of CoP@CoP@(Co/Ni)2P can be attributed to their multi-shell hollow structure for abundant activity centers, and rich defect structure for the enhanced intrinsic activity. This work provides new insights into the design and synthesis of multi-shell hollow structures with diverse compositions and defect-rich catalysts for energy storage and conversion application.