A Graphdiyne Nanoreactor for Conversion of NO3− to NH3 from Wastewater

Abstract

AbstractThe lack of highly active and selective catalysts is a major obstacle to replace traditional Haber–Bosch process for electrocatalytic production of ammonia (NH3) at ambient conditions. A new hollow graphdiyne nanoreactor (GDYNR) is reported to overcome this issue effectively. The GDYNR is synthesized by in situ growth of GDY on the inner and outer surfaces of the cobalt hydroxide sphere to form a high‐performance interface structure. Experimental results demonstrate that the incomplete charge transfer between GDY and cobalt atoms at the interfaces promotes the formation of strong interfacial sp‐C─Co bonds and the transition of monovalent Co(II) to mixed Co(II)/Co(III) phases. These intrinsic characteristics give the GDYNR superior NH3 production performances with the highest NH3 yield rate (YNH3) of 479 830.67 µgNH3 mgcat−1 h−1, Faradaic efficiency (FE) of ≈100% at −0.4 V versus reversible hydrogen electrode, and excellent long‐term stability at room temperatures and ambient pressures, along with no side reactions. In light of characteristics of the unique confined hollow structures and the heterointerface with obvious incomplete charge transfer property, the generation of GDYNR system represents an advanced design concept and preparation technology for the development of catalytic systems with new structures.