Ni Center Coordination Reconstructed Nanocorals for Efficient Water Splitting

Efficient electrocatalytic reactions require a coordinated active center that may provide a properly reaction intermediates adsorption in water splitting. Herein, a Ni active center coordination reconstruction method achieved by multidimensional modulation of phase transition, iodine coordination, and vacancy defects is designed and implemented. This coordination reconstruction results in the successful synthesis of Ni5P4-xIx/Ni2P nanocorals that show outstanding bifunctional catalytic activity due to deep optimization of the adsorption energy. The overpotentials of hydrogen evolution reaction and oxygen evolution reaction at 10 mA cm(-2) are 46 and 163 mV, respectively. Only 1.46 V is required to drive alkaline overall water splitting. Novel coordination environment is investigated by electron paramagnetic resonance spectroscopy and extended X-ray absorption fine structure spectroscopy. A 4D integrated material design strategy of thermodynamic stability-electronic properties-charge transfer-adsorption energy for water-splitting catalysts is proposed. This coordination reconstruction concept and material design method provide new perspectives for the research of novel catalysts.

Automated summary

In this study, a Ni active center coordination reconstruction method is designed and implemented by multidimensional modulation of phase transition, iodine coordination, and vacancy defects, resulting in the successful synthesis of Ni5P4-xIx/Ni2P nanocorals. These nanocorals exhibit outstanding bifunctional catalytic activity with overpotentials of 46mV and 163mV for hydrogen evolution reaction and oxygen evolution reaction, respectively. The novel coordination environment is revealed by electron paramagnetic resonance spectroscopy and extended X-ray absorption fine structure spectroscopy. The study proposes a 4D integrated material design strategy for water-splitting catalysts and provides new perspectives for the research of novel catalysts.