Local Enhanced Electric Field Assisted Electrocatalytic Nitrate Reduction to Ammonia Using Ni(TCNQ) <sub>2</sub> /NF Nanostructures
Nilmadhab Mukherjee, Ashadul Adalder, Sourav Paul, Narad Barman, Ranjit Thapa, Koushik Mitra, Rajashri Urkude, Uttam Kumar Ghorai
Abstract
Abstract Environmentally sustainable electrocatalytic nitrate reduction (NO 3 RR) is a very promising method for the synthesis of ammonia at room temperature via the complex eight‐electron/nine‐proton transfer mechanism. Herein, the local electric field‐assisted electrochemical NO 3 RR process is proposed to identify the origin of catalytic activity and charge transfer kinetics resulting from different morphologies of the electrocatalyst. Accordingly, Ni(TCNQ) 2 /NF nanorods (NRs) and nanotips (NTs) are fabricated on Ni foam as electrocatalysts for the NO 3 RR. The Ni(TCNQ) 2 /NF NTs exhibits an impressive ammonia yield of up to 11286.9 µg h −1 cm − 2 and a Faradaic efficiency (FE) of 83.7% at −1.0 V versus RHE, representing nearly a 2.2‐fold increase in yield compared to the Ni(TCNQ) 2 /NF NRs. This greater performance is attributed to the local enhanced electric field (LEEF) generated at the tip‐like Ni(TCNQ) 2 /NF NTs. Furthermore, a Zn–NO 3 − battery is developed here, and Ni(TCNQ) 2 /NF NTs shows a maximum power density of 2.15 mW cm −2 . Experimental and computational findings demonstrate that the geometric and electrical properties of the nanostructures' shape significantly influence the electrochemical NO 3 RR by enhancing the kinetics of charge transfer. This study seeks to advance research on morphology‐dependent electrochemical NO 3 RR through the strategic control of local electric field intensity in electrocatalysts.