Boosting the electrochemical nitrogen reduction by rhenium-doping modulated TiO2 nanofibers

Abstract

To improve the electrocatalytic activity of catalysts, tailoring the electronic structures of catalysts by transition metal doping and defect engineering is an efficient method. Herein, two methods are skillfully combined to modulate the structure of TiO2 toward the electrochemical N2 reduction reaction through rhenium doping, which concurrently induced the generation of abundant grain boundaries and oxygen vacancies. The prepared Re-doped TiO2 nanofibers exhibited a considerable average ammonia yield rate (22.7 µg h−1 mgcat.−1) and Faradaic efficiency (18.1 %) at an applied potential of -0.3 V vs. RHE. Experimental results, combined with theoretical calculations, reveal that rhenium doping is beneficial to improving the reducibility and conductivity of TiO2, thus favoring the NRR process. All these results prove that this work can provide a new avenue to design the next generation of electrocatalysts for NRR.