Oxygen-deficient SnO2 nanoparticles with ultrathin carbon shell for efficient electrocatalytic N2 reduction
Guangkai Li, Haeseong Jang, Zijian Li, Jia Wang, Xuqiang Ji, Min Gyu Kim, Xien Liu, Jaephil Cho
Abstract
For high-efficiency NH3 synthesis via ambient-condition electrohydrogenation of inert N2, it is pivotal to ingeniously design an active electrocatalyst with multiple features of abundant surfacial deficiency, good conductivity and large surface area. Here, oxygen-deficient SnO2 nanoparticles encapsulated by ultrathin carbon layer (d-SnO2@C) are developed by hydrothermal deposition coupled with annealing process, as promising catalysts for ambient electrocatalytic N2 reduction. d-SnO2@C exhibits high activity and excellent selectivity for electrocatalytic conversion of N2 to NH3 in acidic electrolytes, with Faradic efficiency as high as 12.7% at −0.15 V versus the reversible hydrogen electrode (RHE) and large NH3 yield rate of 16.68 μg h−1 mgcat−1 at −0.25 V vs. RHE in 0.1 mol L−1 HCl. Benefiting from the structural superiority of enhanced charge transfer efficiency and optimized surface states, d-SnO2@C also achieves excellent long-term stability.