Ambient Electroreduction of Nitrite to Ammonia over Ni Nanoparticle Supported on Molasses-Derived Carbon Sheets

Abstract

Electrochemical nitrite (NO2 –) reduction is a promising approach for ambient ammonia (NH3) synthesis and simultaneous mitigation of NO2 – contaminant in wastewater. Herein, we report Ni nanoparticle supported on molasses-derived carbon sheets (Ni@MDC) as an earth-abundant electrocatalyst for NO2 –-to-NH3 conversion. When tested in alkaline solutions with 0.1 M NO2 –, such Ni@MDC obtains a high NH3 yield of 6.3 mg h–1 mgcat –1 with a Faradaic efficiency of 65.4% at −0.8 V versus reversible hydrogen electrode under ambient conditions. Furthermore, it shows remarkable electrochemical stability during long-term electrolysis and cycling tests.

Ni@TiO2 Nanoarray with the Schottky Junction for the Highly Selective Electrochemical Reduction of Nitrite to Ammonia

“…As shown in Figure h, two fitting peaks at the bond energies (BEs) of 851.92 and 872.4 eV in the Ni 2p region are assigned to Ni 2p 3/2 and Ni 2p 1/2 of Ni, respectively. And the BEs located at 855.64 and 873.66 eV are assigned to Ni 2p 3/2 and Ni 2p 1/2 of Ni 2+ , which arise from surface oxidation of Ni exposed to air. , In the Ti 2p region (Figure i), two recognizable peaks at the BEs of 458.33 and 464.02 eV are assigned to Ti 2p 3/2 and Ti 2p 1/2 , respectively, and show a little shift toward the low energy direction compared with that of TiO 2 , demonstrating the charge transfer from Ni to TiO 2 . , Besides, the high-resolution O 1s spectrum is deconvoluted into two peaks centered on 529.59 (M–O) and 531.44 eV (M–OH), respectively, , and there are also shifts toward lower BEs of Ni@TiO 2 . These analysis results confirm successful preparation of the Ni@TiO 2 nanoarray.…”

“…Compared with TiO 2 /TP, Ni@TiO 2 /TP has additional characteristic peaks at 44.5°, 51.9°, and 76.5° that are indexed to the (111), (200), and (200) lattice planes of Ni, respectively (JCPDS No. 04-0850). , Their common peaks arise from TP (JCPDS No. 44-1294) and TiO 2 (JCPDS No.…”

“…Researchers have been exploring the design of advanced catalysts based on a transition metal for the NO 2 – RR, − ,− with particular attention given to metallic Ni. ,, Fabricating a metal–semiconductor Schottky junction adopting active metal and semiconductor components has been demonstrated to efficiently enhance the electrocatalytic performance. , Different Feimi levels of the metal and semiconductor can cause electron transfer. More exactly, it can produce a built-in electric field, accelerating electron transfer at the interface and promoting local charge polarization, thereby greatly improving the adsorption of the critical reaction intermediates .…”

Spin-engineered Cu–Ni metallic aerogels for enhanced ethylamine electrosynthesis from acetonitrile

“…Ethylamine is one of the simplest amines and is widely used in hydrogen-storage devices, organic chemical reactions, energy conversion, and so on. [1][2][3][4][5][6][7][8][9][10][11] There are many ways to obtain ethylamine in industry, such as through the ammoxidation of ethanol, 12,13 reductive ammoniation of acetaldehyde, 14,15 and hydrogenation of acetonitrile. 16,17 Among these, acetonitrile, a byproduct of acrylonitrile produced by the Sohio process, has attracted increasing attention because of its easy access to raw materials.…”

High-efficiency electroreduction of nitrite to ammonia on a Cu@TiO2 nanobelt array

“…In contrast, nitrite (NO 2 À ) features the lower NQO bond energy and higher water solubility, which makes it endowed with faster reaction kinetics compared with the NRR for NH 3 electrosynthesis. 15,16 Besides, the excess NO 2 À pollutant accumulated in aquatic ecosystems has ineluctably caused global nitrogen cycle imbalance and meanwhile harms public health. 17 Therefore, the electrochemical nitrite reduction reaction (NO 2 À RR) is a winwin strategy for producing value-added NH 3 and simultaneously removing hazardous NO 2…”