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

Abstract

The 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.

Controlled Synthesis of Graphdiyne-Based Multiscale Catalysts for Energy Conversion

“…In general, the Cu nanowires array was prepared through electrochemical anodization of Cu foam followed by a chemical reduction procedure, and then the cross-coupling reaction of HEB occurred on as-prepared Cu nanowires to form a Cu@GDY heterostructure. It is also important to realize the precisely controlled construction of GDY/nanoparticles heterostructured catalysts with highly active heterogeneous interfaces, which has drawn increasing attention from researchers. − Li et al reported the GDY@Janus magnetite heterostructure with excellent performance for photocatalytic nitrogen fixation . In their work, GDY was used as the substrate to absorb Fe 2+ ions, followed by a nucleation and growth process of FeO x nanoparticles, in which GDY played an important role to change the morphology, coordination environment, and valence states of FeO x .…”

Controlled Growth of PtCux Quantum Dots on Graphdiyne for Efficient Ammonia Production

“…Incorporating metal catalysts with carbon materials has been considered as an effective way to maximize the number of the active sites, improve the intrinsic activity, and achieve high-performance catalysts. − As a rising star of carbon material, graphdiyne (GDY) shows great application value in catalysis field due to its promising and distinctive properties, including the unique sp/sp 2 cohybridized all-carbon network, natural pores, natural band gap, superlarge π structures, abundant carbon chemical bonds, unevenly distributed surface charge, and high intrinsic activity, etc. − Remarkably, the unique noninteger charge transfer between GDY and metal atoms can effectively regulate the electronic structure of active sites, promoting the adsorption and conversion of NO 3 – , resistance to intermediate toxicity, and selective N–H coupling. − These unique advantages of GDY make it an ideal platform for the construction of new catalysts to realize the highly efficient reduction of nitrate to NH 3 .…”

“…These results significantly deviate from the typical alloy structure, which is predominantly composed of zerovalent metal. The strong interactions between GDY and PtCu x QDs induce the formation of mixed valent metal atoms, thereby endowing high catalytic activity upon the catalyst. , …”

“…To this end, large amounts of NtRR catalysts have been synthesized and reported by researchers. Among them, metal catalysts have shown excellent catalytic performances in this field. − But the low binding affinity of NO 3 – toward metal-based catalysts and the complex eight-electron transfer process during NtRR largely reduced the overall catalytic activity and selectivity. − The design and synthesis of new catalysts with desired selectivity and activity are the key steps for large-scale NH 3 production at room temperatures and ambient pressures to meet the industrial requirements.…”