Porous Mn-doped FeP/Co3(PO4)2 Nanosheet Arrays as an efficient Electrocatalyst for pH-Universal Overall Water Splitting.

Development of highly active and stable electrocatalysts for overall water splitting is important for future renewable energy systems. Herein, we designedly fabricated porous Mn-doped FeP/Co3(PO4)2 (PMFCP) nanosheets on carbon cloth, which can be utilized as a highly efficient 3D self-supported binder-free integrated electrode for the oxygen- and hydrogen- evolution reactions (OER and HER) in a wide pH range. Specifically, overpotentials of 27, 117, 85 mV are required for the PMFCP nanosheets to arrive 10 mA cm-2 for HER in 0.5 M H2SO4, 1.0 M phosphate-buffered saline (PBS), and 1.0 M KOH, respectively. In addition to the excellent performance for HER electrocatalysis, PMFCP were also efficient electrocatalysts for OER. Thus, we use the PMFCP nanosheets as anodes and cathodes to perform overall water splitting (OWS), and the OWS working voltages are found to be 1.75 V, 1.66 V, and 1.61 V for affording 10 mA cm-2 in acid, neutral, and alkaline electrolytes, respectively. Meantime, as proved by chronopotentiometric tests, the PMFCP electrode can maintain its excellent pH-universal OWS activity for more than 30,000 s. This work also provides new insights into developing high-performance electrocatalyst for water splitting in wide pH range. The success of improving the electrochemical performance via the introduction of Mn element and nano-holes offers new opportunities in the development of high-performance electrodes for other energy-related applications.