Facile and rapid synthesis of hierarchical LDHs array by universal molten salt with bound water toward efficient oxygen evolution electrocatalysis

Layered double hydroxide (LDH) is a kind of intensive used and highly efficient electrocatalyst. However, the traditional ways to prepare LDHs are time-consuming and energy cost and the electrochemical properties need to be further improved. Herein, we verified that bound water could exist in the molten salt at a temperature over 190℃. Hence, we developed the molten salt with bound water method (MSBWM), manufacturing hierarchical LDHs one step in molten salt. The as-obtain LDHs exhibit more excellent oxygen evolution reaction (OER) performance than corresponding hydrothermal synthesized. Their morphology and electronic structure were analyzed and compared carefully, indicating the unique and excellent characteristics of electrocatalysts made by MSBWM. Especially, FeCoNi LDH only needs 218 mV overpotential to drive 10 mA cm−2 and negligible descent after 24 h stability test. The unique advantages and easy-to-meet preparation conditions promise the MSBWM flexible design and large-scale preparation of hierarchical (oxy)hydroxides as advanced electrocatalysts.