Regulating the electronic structure of Ni₃Se₄-MoSe₂ by coupling with ZIF-derived Co@C promotes boosted urea-assisted water splitting at industrial current density

Adopting urea oxidation reaction (UOR) as an alternative to oxygen evolution reaction (OER) is a prospective approach to achieve energy-saving H₂ generation as well as purify wastewater with abundant urea, while the industrial application of bifunctional catalysts for hydrogen evolution reaction (HER) and UOR still remains challenge. Herein, novel coleslaw-like arrays Ni₃Se₄-MoSe₂/Co@C electrocatalyst is fabricated by coupling Ni₃Se₄-MoSe₂ heterointerface with Co-ZIF derived Co@C, in which the synergistic effects of Ni₃Se₄-MoSe₂ and Co@C can tailor the electronic state caused by Ni, Mo, Se and Co atoms, contributing to the modulated d-band center and charge redistribution, hence balancing the absorption and desorption of HER and UOR reaction intermediates and realizing facilitated HER and UOR activities. Furthermore, the coleslaw-like arrays could expose more active sites as well as speed up mass transport. As a result, Ni₃Se₄-MoSe₂/Co@C shows ultralow potentials of 189 mV and 1.427 V to achieve industrial current density of 1000 mA·cm⁻² with small Tafel slopes of 56.5 and 30.2 mV·dec^-1 towards HER and UOR with exceptional long durability, respectively. Impressively, a remarkably decreased cell voltage of 1.98 V is seen to achieve 1000 mA·cm⁻² for urea-assisted water splitting. This study introduces a new strategy to producing non-noble-based selenides with ZIF derivative to realize bifunctional application in energy-saving H₂ production with industrial treatment of urea wastewater.