Rational construction of N,S-doped carbon wrapped MnFe2O4 nanospheres with copious oxygen deficiency as extremely efficient and robust electrocatalyst for urea electrocatalysis

Abstract

Here, we fabricated N,S-Carbon (NSC) enfolded MnFe2O4 (MFO) nanospheres with abundant oxygen defects (OV), exploited as brilliant electrocatalyst for urea oxidation reaction (UOR) and hydrogen evolution reaction (HER). This typical nanoarchitecture possesses many characteristic compensations, (i) incorporation of OV in MFO to moderate the electronic arrangement for enhancing the electrons mobility and offering additional space for electrocatalysis and rapid absorption/diffusion of ions, (ii) homogeneously dispersed MFO nanospheres with great number of active sites and excellent catalytic activity, (iii) robust interaction between NSC and MFO ensuring the longstanding electrochemical stability, which are favorable to enhancing the kinetics of urea electrocatalysis. Electrochemical measurements proved NSC-MFO possesses outstanding UOR activity that shows a low potential of 1.42 V to attain 50 mA/cm2, too NSC-MFO contributes to excellent HER activity with low overpotential of 0.192 V to attain 50 mA/cm2. The excellent UOR performance of NSC-MFO authenticates could be wonderful applicant to replace OER to lower the cell potential thus decrease consumption of electrical energy for hydrogen-gas generation. As a proof of concept, overall urea splitting has been done with NSC-MFO as both cathode and anode, as-fabricated urea electrolytic cell offered 10 mA/cm2 at the cell voltage of 1.43 V with good durability for 15 h, displaying its potential practicability for energy-saving hydrogen making.