It is highly attractive but challenging to develop earth-abundant electrocatalysts for energy-saving electrolytic hydrogen generation. Herein, we report that Ni P nanoarrays grown in situ on nickel foam (Ni P/NF) behave as a durable high-performance non-noble-metal electrocatalyst for hydrazine oxidation reaction (HzOR) in alkaline media. The replacement of the sluggish anodic oxygen evolution reaction with such the more thermodynamically favorable HzOR enables energy-saving electrochemical hydrogen production with the use of Ni P/NF as a bifunctional catalyst for anodic HzOR and cathodic hydrogen evolution reaction. When operated at room temperature, this two-electrode electrolytic system drives 500 mA cm at a cell voltage as low as 1.0 V with strong long-term electrochemical durability and 100 % Faradaic efficiency for hydrogen evolution in 1.0 m KOH aqueous solution with 0.5 m hydrazine.

NH3 is a valuable chemical with a wide range of applications, but the conventional Haber–Bosch process for industrial‐scale NH3 production is highly energy‐intensive with serious greenhouse gas emission. Electrochemical reduction offers an environmentally benign and sustainable route to convert N2 to NH3 at ambient conditions, but its efficiency depends greatly on identifying earth‐abundant catalysts with high activity for the N2 reduction reaction. Here, it is reported that MnO particles act as a highly active catalyst for electrocatalytic hydrogenation of N2 to NH3 with excellent selectivity. In 0.1 m Na2SO4, this catalyst achieves a high Faradaic efficiency up to 8.02% and a NH3 yield of 1.11 × 10−10 mol s−1 cm−2 at −0.39 V versus reversible hydrogen electrode, with great electrochemical and structural stability. On the basis of density functional theory calculations, MnO (200) surface has a smaller adsorption energy toward N than that of H with the *N2 → *N2H transformation being the potential‐determining step in the nitrogen reduction reaction.

The conventional Haber‐Bosch process for industrial ammonia production from N2 and H2 is not only energy‐intensive but also releases a large amount of CO2. The electrocatalytic nitrogen reduction reaction (NRR) is regarded as a sustainable and environmentally‐benign alternative approach for NH3 production under ambient conditions. In this communication, it is reported that Fe2O3 nanorods act as an efficient electrocatalyst for the NRR. In 0.1 M Na2SO4, it attains a Faradic efficiency of 0.94 % and NH3 yield of 15.9 μg h−1 mg−1cat. at −0.8 V vs. reversible hydrogen electrode. Furthermore, this catalyst also shows good stability during electrolysis and recycling tests.

No abstract

High-performance supercapacitors require the design and development of electrode materials with high conductivity and a large electrolyte-accessible surface area. Here, the use of a conductive NiCoP nanoarray on nickel foam (NiCoP/NF) as a superior pseudocapacitor electrode is demonstrated. This 3D electrode exhibits high areal capacitances of 9.2 and 5.97 F cm at current densities of 2 and 50 mA cm , respectively, with good rate capability and cycling stability. The asymmetric supercapacitor (ASC) device assembled using NiCoP/NF as positive electrode and active carbon as negative electrode delivers a high energy density of 1.16 mWh cm at a power density of 1.6 mW cm with 72 % retention of its initial specific capacitance after 2000 cycles at 50 mA cm . The practical use is further demonstrated with two such ASC devices in series to light six LED indicators and also to drive an alkaline water electro- lyzer using NiCoP/NF as both cathode and anode for hydrogen production.

It is highly attractive to develop non-noble-metal nanoarray architecture as a 3D-catalyst electrode for molecular detection due to its large specific surface area and easy accessibility to target molecules. Here, we report the development of a copper-nitride nanowires array on copper foam (Cu N NA/CF) as a dual-functional catalyst electrode for efficient glucose oxidation in alkaline solutions and hydrogen peroxide (H O ) reduction in neutral solutions. Electrochemical tests indicate that such Cu N NA/CF possesses superior non-enzymatic sensing ability toward rapid glucose and H O detection with high selectivity. At 0.40 V, this sensor offers a high sensitivity of 14 180 μA mm cm for glucose detection, with a wide linear range from 1 μm to 2 mm, a low detection limit of 13 nm (S/N=3), and satisfactory stability and reproducibility. Its application in determining glucose in human blood serum is also demonstrated. Amperometric H O sensing can also been realized with a sensitivity of 7600 μA mm cm , a linear range from 0.1 μm to 10 mm, and a detection limit of 8.9 nm (S/N=3). This 3D-nanoarray architecture holds great promise as an attractive sensing platform toward electrochemical small molecules detection.

Electrode design is of significant importance in the construction of enhanced electrochemical sensing platforms, and nanoarrays are an attractive architecture in molecule detection with large specific surface area and easy access for target molecules. In this communication, we report on the development of a ternary NiCoP nanosheet array on a Ti mesh (NiCoP/Ti) as a non-noble metal efficient catalyst electrode for electro-oxidation of glucose in alkaline electrolytes. As an electrochemical sensor for glucose detection, NiCoP/Ti shows a fast response time of less than 3 s, a low detection limit of 0.13 μM (S/N = 3), and a high sensitivity of 14 586 μA mM cm. This sensor is also stable with high selectivity, specificity and reproducibility, and its application for real sample analysis is also demonstrated successfully.

Among reported electrode materials, a nanoarray is an attractive architecture for molecular detection because of its large specific surface area and easy accessibility for target molecules. Here, a new Fe N-Co N nanowires array grown on carbon cloth (Fe N-Co N/CC) is reported as a non-noble-metal bifunctional catalyst electrode for high-performance glucose oxidation and H O reduction. As an electrochemical non-enzymatic sensor for glucose detection, Fe N-Co N/CC shows a fast response time of 8 s, a low detection limit (LOD) of 77 nm (signal/noise=3), and a high sensitivity of 4333.7 μA mm cm . As an H O sensor, it shows a LOD of 59 nm (signal/noise=3) and a sensitivity of 2273.8 μA mm cm with a response time of 2 s. In addition, the proposed sensor is stable with high selectivity, specificity, and reproducibility, and its application for real sample analysis has been successfully demonstrated.