Spatial Compartmentalization of Cobalt Phosphide in P-Doped Dual Carbon Shells for Efficient Alkaline Overall Water Splitting

Santosh V Mohite; Ruimin Xing; Bingyue Li; Sanjay S Latthe; Yong Zhao; Xiying Li; Liqun Mao; Shanhu Liu

doi:10.1021/acs.inorgchem.9b03363

Spatial Compartmentalization of Cobalt Phosphide in P-Doped Dual Carbon Shells for Efficient Alkaline Overall Water Splitting

Inorg Chem. 2020 Feb 3;59(3):1996-2004. doi: 10.1021/acs.inorgchem.9b03363. Epub 2020 Jan 10.

Authors

Santosh V Mohite¹, Ruimin Xing¹, Bingyue Li¹, Sanjay S Latthe¹, Yong Zhao², Xiying Li¹, Liqun Mao¹, Shanhu Liu¹

Affiliations

¹ Henan Key Laboratory of Polyoxometalate Chemistry, Henan Engineering Research Center of Resource & Energy Recovery from Waste, College of Chemistry and Chemical Engineering , Henan University , Kaifeng , 475004 , P. R. China.
² Key Lab for Special Functional Materials of Ministry of Education, Collaborative Innovation Center of Nano Functional Materials and Applications , Henan University , Kaifeng , 475004 , P. R. China.

PMID: 31922740
DOI: 10.1021/acs.inorgchem.9b03363

Abstract

Highly durable and earth-abundant bifunctional catalysts with low cell voltage are desirable for alkaline overall water splitting in the industrial fields. Herein, a novel carbon-based CoP hybrid with spatial compartmentalization of CoP nanoparticles (NPs) in P-doped dual carbon shells is achieved via a cheap Co-glycerate-template strategy. Benefitted from the uniform atomic blending of Co²⁺ ions in the Co-glycerate precursors, CoP NPs in situ formed in the confined space with NaH₂PO₂ as phosphorus source during the annealing process; meanwhile, glycerate suffered carbonization and transformed into P-doped dual carbon shells during the annealing process, including interior thin carbon coating, closely encircled CoP NP, and peripheral hollow carbon sphere loading a lot of CoP NPs. Not only does spatial compartmentalization of CoP NPs avoid the aggregation and expose more active sites but also P-doped dual carbon shells improve the conductivity and durability of the catalyst. As expected, the optimized hybrid exhibits outstanding electrocatalytic activities in alkaline media, such as hydrogen evolution reaction (HER) overpotential of 101 mV, oxygen evolution reaction (OER) overpotential of 280 mV, and a low cell voltage of 1.66 V to deliver a current density of 10 mA cm^-2. Moreover, durability and stability are greatly improved under harsh electrochemical conditions. The current strategy shades new insight into the development of carbon-based transition metal phosphides (TMP) catalysts for electrocatalysis applications.