Industrially, NH3 synthesis is largely dependent on the Haber–Bosch method which consumes a lot of energy and emits huge amounts of CO2. Recently, the electrochemical N2 reduction reaction (NRR) has been recognized as a promising method to achieve clean and sustainable NH3 production, thus highly efficient and durable catalysts are urgently desired. In this paper, we report a MOF-derived carbon/Y-stabilized ZrO2 nanocomposite (C@YSZ) that works as an efficient electrocatalyst for NRR in 0.1 M Na2SO4. It achieves a large NH3 production of 24.6 μg h−1 mgcat.−1 and a high faradaic efficiency of 8.2% at −0.5 V vs. the reversible hydrogen electrode. The experimental results demonstrate that the surface oxygen vacancies are the main catalytic sites for NRR. Introducing Y3+ into the ZrO2 lattice has a significant effect to increase and stabilize the O-vacancies. Meanwhile, this catalyst displays remarkable stability and durability for NRR, showing negligible change after 7 days reaction, which is better than most reported NRR electrocatalysts. Moreover, an in situ electrochemical quartz-crystal microbalance (EQCM) was applied in the NRR field for the first time and was successfully combined with density functional theory (DFT) calculations to reveal the deactivation mechanism.

Long-term electrocatalytic N2 fixation by MOF-derived Y-stabilized ZrO2: insight into the deactivation mechanism

An insight into the promotion effect of Na+/vacancy ordering on desalination performance of NaxCoO2

The world is suffering from chronic water shortage due to the increasing population, water pollution and industrialization. Desalinating saline water offers a rational choice to produce fresh water thus resolving the crisis. Among various kinds of desalination technologies, capacitive deionization (CDI) is of significant potential owing to the facile process, low energy consumption, mild working conditions, easy regeneration, low cost and the absence of secondary pollution. The electrode material is an essential component for desalination performance. The most used electrode material is carbon-based material, which suffers from low desalination capacity (under 15 mg·g−1). However, the desalination of saline water with the CDI method is usually the charging process of a battery or supercapacitor. The electrochemical capacity of battery electrode material is relatively high because of the larger scale of charge transfer due to the redox reaction, thus leading to a larger desalination capacity in the CDI system. A variety of battery materials have been developed due to the urgent demand for energy storage, which increases the choices of CDI electrode materials largely. Sodium-ion battery materials, lithium-ion battery materials, chloride-ion battery materials, conducting polymers, radical polymers, and flow battery electrode materials have appeared in the literature of CDI research, many of which enhanced the deionization performances of CDI, revealing a bright future of integrating battery materials with CDI technology.

https://www.mdpi.com/2073-4441/12/11/3030/pdf

A Review of Battery Materials as CDI Electrodes for Desalination

Simultaneously regulating the physical properties and chemical environment of interlayer is a critical need for enhancing the capacity and stability of layered electrode materials in energy and env...

Enhanced Desalination Capacity and Stability of Alkylamine-Modified Na0.71CoO2 for Capacitive Deionization

Revealing the role of the amorphous phase in Na0.74CoO2/C/N composite cathode

Faradaic deionization (FDI) provides an effective solution to respond to the global water crisis. However, the ions intercalation/deintercalation process with multiple redox reactions leads to structural collapse and unstable cyclability. Here, we develop an asymmetrical FDI device assembled by Ca2+-decorated NaxCoO2 (x ≤ 0.71, y ≤ 0.05) as the Faradaic negative electrode and activated carbon as the positive electrode. Na0.27Ca0.03CoO2·0.6H2O was synthesized via a facile sol–gel and chemical oxidation method, which delivered a desalination capacity of 83.5 ± 2.4 mg g–1 and a charge efficiency close to 1, and an inappreciable capacity fading was observed after 50 cycles. It is found that the presence of Ca2+ residing in the face-sharing sites helps to maintain the layered structure and promotes efficient deintercalation of Na+ by anchoring the CoO2 slabs, which results in its unexpected desalination capacity and good cyclability. Moreover, electrochemical quartz-crystal microbalance (EQCM) was successfully...

Shijian Luo

Papers

More Ca 2+ , Less Na + : Increasethe Desalination Capacity and Performance Stability of Na x Ca y CoO 2