Carbon dots modified nanoflower petals with super enhanced nitrogen electro-reduction efficiency

Abstract

Nitrogen electro-reduction reaction (NERR) is a promising alternative method for ammonia production to the Haber–Bosch approach due to mild reaction conditions and free harmful by-product emission. A formidable challenge in bringing NERR closer to the practical application is developing an electro-catalyst which can simultaneously improve the Faraday efficiency and reduce the reaction over-potential. Herein, we fabricated a catalyst of nitrogen-doped carbon dots modified copper-phosphate nanoflower petals (CuPo-NCDs NF) via a self-assembly method. The flower structure endowed the CuPo-NCDs NF with large specific surface area, and thus enabled more active sites to be exposed. In particular, we demonstrated that the NCDs modified CuPo petals with flower-like structure can accelerate the interfacial proton-electron transfer, suppressing the competing hydrogen evolution reaction and promoting the desired NERR process. Ultimately, for the CuPo-NCDs NF catalyzed NERR, the FENH3 and the reaction potential both were boosted, the resultant energy efficiency of NERR reached a record-breaking value of 56.5%, and the NH3 yield rate increased by 7 times compared to NCDs. This study provides a novel catalyst with a new pathway to boost the NERR.