Search

Herein, a brush-like Cu2O–CoO core–shell nanoarray on copper foam (Cu2O–CoO/CF) can achieve efficient oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) performance in alkaline seawater electrolyte. This Cu2O–CoO/CF shows overpotentials as low as 315 and 295 mV at 100 mA cm−2 for the OER and HER, respectively. Moreover, it could also be operated at 1.82 V with 100 mA cm−2 in a two-electrode electrolyzer and exhibits strong stability for at least 50 hours of electrolysis. The excellent performance and hierarchical structure advantages of Cu2O–CoO/CF provide new ideas for designing efficient seawater splitting electrocatalysts. [ABSTRACT FROM AUTHOR]

Electrocatalytic nitrite reduction not only holds significant potential in the control of nitrite contamination in the natural environment, but also is an attractive approach for sustainable ammonia synthesis. In this communication, we report that a TiO2−x nanobelt array with oxygen vacancies on a titanium plate is able to convert nitrite into ammonia with a high faradaic efficiency of 92.7% and a large yield of 7898 μg h−1 cm−2 in alkaline solution. This monolithic catalyst also shows high durability with the maintenance of its catalytic activity for 12 h. Theoretical calculations further reveal the critical role of oxygen vacancies in nitrite electroreduction. [ABSTRACT FROM AUTHOR]

Electrocatalytic reduction of nitrite (NO2−) to ammonia (NH3) can simultaneously achieve wastewater treatment and ammonia production, but it needs efficient catalysts. Herein, Cu2O particles self-supported on Cu foam with enriched oxygen vacancies are developed to enable selective NO2− reduction to NH3, exhibiting a maximum NH3 yield rate of 7510.73 μg h−1 cm−2 and high faradaic efficiency of 94.21% at − 0.6 V in 0.1 M PBS containing 0.1 M NaNO2. Density functional theory calculations reveal the vital role of oxygen vacancies during the nitrite reduction process, as well as the reaction mechanisms and the potential limiting step involved. This work provides a new avenue to the rational design of Cu-based catalysts for NH3 electrosynthesis. [ABSTRACT FROM AUTHOR]

Electrocatalytic NO reduction controls NO emission and produces NH3 under ambient conditions. Herein, a NiO nanosheet array on titanium mesh is proposed as a highly active and selective electrocatalyst for NO reduction, attaining a faradaic efficiency of up to 90% with a NH3 yield of 2130 μg h−1 cm−2. Its aqueous Zn–NO battery can generate electricity with a power density of 0.88 mW cm−2 and simultaneously offer an NH3 yield of 228 μg h−1 cm−2. The NO electroreduction mechanism on NiO is revealed using theoretical calculations. [ABSTRACT FROM AUTHOR]