Tuning Nitrate Electroreduction Activity via an Equilibrium Adsorption Strategy: A Computational Study

Converting nitrates into industrial-value chemicals is of great significance for environmental sustainability. Herein, the electrochemical nitrate reduction reaction (NO3RR) performances of transition metal (TM) anchored g-C3N4 (TM/g-C3N4) were systematically evaluated using density functional theory and ab initio molecular dynamics. A novel equilibrium adsorption model was constructed to screen the excellent catalysts, accelerating high-throughput calculations. As found, Hf/g-C3N4 exhibits remarkable activity with a limiting potential of 0.11 V. Besides, the superior electrode selectivity overwhelmingly depresses the formation of byproducts and greatly speeds up the NO3RR. The electronic structure analysis discloses the origin of the electrocatalytic activity for TM/g-C3N4 and indicates why the IVB group elements have an outstanding role. Finally, the formation energy of the clusters and ab initio molecular dynamics simulations prove their structure has fine stability. This work not only offers high-performance electrode candidates for the NO3RR but also opens up a precedent of electrocatalysis in the field of wastewater treatment of explosives.