CoMo Metal–Organic Framework Derivatives Grown on Ni Foam for Efficient Hydrogen Evolution toward Seawater Splitting

Seawater splitting represents a promising approach for the large-scale production of high-purity hydrogen. However, the presence of impurities and lack of H+ remain great challenges in synthesizing efficient and durable catalysts for direct seawater electrolysis. Heterostructures are widely studied as a feasible strategy to enhance the performances of the seawater splitting catalysts, among which multimetallic MOF derivatives grown on porous substrates show promising activity and stability. Therefore, in this work, we report a facile strategy to construct a multilevel CoMo-MOF-derived metal/carbon nanotubes/NF catalyst. It has been found that the resulting electrocatalyst exhibits attractive performance with overpotentials of 91 and 238 mV at 10 mA cm–2 for HER and OER in alkaline freshwater, respectively. For alkaline and natural seawater splitting, it shows low HER potentials of 92 and 383 mV at 10 mA cm–2, respectively. Moreover, the as-prepared catalyst remains stable over 50 h both in alkaline freshwater and seawater. Experimental results reveal that the attractive electrochemical performance can be attributed to abundant active sites, dispersion and protection of carbon nanotubes, and efficient charge transfer of the self-supporting porous structure. Our work may shed light on designing self-supporting and cost-efficient nanocarbon materials for green hydrogen production from seawater.