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It is highly desirable to develop a simple, fast and straightforward method to boost the alkaline water oxidation of metal oxide catalysts. In this communication, we report our recent finding that the generation of amorphous Co-borate layer on Co3O4 nanowire arrays supported on Ti mesh (Co3O4@Co-Bi NA/TM) leads to significantly boosted OER activity. The as-prepared Co3O4@Co-Bi NA/TM demands overpotential of 304 mV to drive a geometrical current density of 20 mA cm-2 in 1.0 M KOH, which is 109 mV less than that for Co3O4 NA/TM, with its catalytic activity being preserved for at least 20 h. It suggests that the existence of amorphous Co-Bi layer promotes more CoOx(OH)y generation on Co3O4 surface. [ABSTRACT FROM AUTHOR]

Environmentally friendly electrochemical hydrogen production needs the development of earth-abundant catalyst materials for the hydrogen evolution reaction with high activity and durability at neutral pH. In this work, the self-templating construction of a hollow amorphous CoMoS4 nanotube array on carbon cloth (CoMoS4 NTA/CC) is reported, using hydrothermal treatment of a Co(OH)F nanowire array on CC in (NH4)2MoS4 solution. When used as a 3D electrode for hydrogen evolution electrocatalysis, the resulting CoMoS4 NTA/CC demonstrates superior catalytic activity and strong long-term electrochemical durability in 1.0 M phosphate buffer solution (pH=7). It shows small onset overpotential of 21 mV and requires low overpotentials of 104 and 179 mV to drive geometrical current densities of 10 and 50 mA cm−2, respectively. Density functional theory calculations suggest that CoMoS4 has a more favorable hydrogen adsorption free energy than Co(OH)F. [ABSTRACT FROM AUTHOR]

Searching for a simple and fast strategy to effectively enhance the oxygen evolution reaction (OER) performance of non-noble-metal electrocatalysts in alkaline media remains a significant challenge. Herein, the OER activity of NiFe-LDH nanoarray on carbon cloth (NiFe-LDH/CC) in alkaline media is shown to be greatly boosted by an amorphous NiFe-Borate (NiFe-Bi) layer formation on NiFe-layered double hydroxide (NiFe-LDH) surface. Such a NiFe-LDH@NiFe-Bi/CC catalyst electrode only needs an overpotential of 294 mV to drive 50 mA cm−2 in 1.0 m KOH; 116 mV less than that needed by NiFe-LDH/CC. Notably, this electrode also demonstrates strong long-term electrochemical durability. The superior activity is ascribed to the pre-formed amorphous NiFe-Bi layer effectively promoting active species generation on the NiFe-LDH surface. This work opens up exciting new avenues for developing high-performance water-oxidation catalyst materials for application. [ABSTRACT FROM AUTHOR]

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 Fe3N-Co2N nanowires array grown on carbon cloth (Fe3N-Co2N/CC) is reported as a non-noble-metal bifunctional catalyst electrode for high-performance glucose oxidation and H2O2 reduction. As an electrochemical non-enzymatic sensor for glucose detection, Fe3N-Co2N/CC shows a fast response time of 8 s, a low detection limit (LOD) of 77 n m (signal/noise=3), and a high sensitivity of 4333.7 μA m m−1 cm−2. As an H2O2 sensor, it shows a LOD of 59 n m (signal/noise=3) and a sensitivity of 2273.8 μA m m−1 cm−2 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. [ABSTRACT FROM AUTHOR]