Oxygen-Vacancy-Rich Cu 2 O Hollow Nanocubes for Nitrate Electroreduction Reaction to Ammonia in a Neutral Electrolyte.

The electrocatalytic nitrate reduction reaction (NO 3 - -ERR) to ammonia (NH 3 ) is a promising strategy for NH 3 production. Cu-based nanomaterials have been regarded as a kind of effective NO 3 - -ERR catalysts. In this work, high-quality hollow Cu 2 O nanocubes (Cu 2 O h-NCs) are facilely synthesized by a simple one-step reduction method. The as-prepared Cu 2 O h-NCs reveal high selectivity and activity for NO 3 - -ERR, which is ascribed to abundant oxygen vacancies, high surface area, hollow architecture, low mass transfer resistance, and strong adsorbing ability toward NO 3 - . In fact, Cu 2 O h-NCs can achieve a Faradic efficiency of 92.9% and an NH 3 yield of 56.2 mg h -1 mg cat -1 for NH 3 production at -0.85 V ( vs RHE) potential, which exceeds those of other transition-metal-based NO 3 - -ERR electrocatalysts.