1.College of Science, and Institute of Oxygen Supply, Tibet University, Lhasa, 850000, People’s Republic of China ;2.State Key Laboratory of Electronic Thin Films and Integrated Devices, and School of Electronic Science and Engineering, University of Electronic Science and Technology of China, Chengdu, 610054, People’s Republic of China ;3.State Key Laboratory of Optical Technologies on Nano-Fabrication and Micro-Engineering, Institute of Optics and Electronics, Chinese Academy of Sciences, Chengdu, 610209, People’s Republic of China ;
Abstract:
Oxygen evolution reaction (OER) for water splitting has a sluggish kinetics, thus significantly hindering the reaction efficiency. So far, it is still challenging to develop a cost-efficient and highly active catalyst for OER processes. To address such issues, we design and synthesize NiP2/FeP heterostructural nanoflowers interwoven by carbon nanotubes (NiP2/FeP@CNT) by a hydrothermal reaction followed by phosphating. The NiP2/FeP@CNT catalyst delivers excellent OER performance: it displays an ultralow Tafel slope of 44.0 mV dec?1 and a relatively low overpotential of 261 mV at 10 mA cm?2, better than RuO2 commercial catalyst; it also shows excellent stability without observable decay after 20-h cycling. The outstanding OER property is mainly attributed to its special 3D stereochemical structure of CNT-interwoven NiP2/FeP heterostructural nanoflowers, which is highly conductive and guarantees considerable active sites. Such nanostructure greatly facilitates the charge transfer, which significantly improves its electrocatalytic activity. This work offers a simple method to synthesize non-precious transition metal-based phosphide electrocatalysts with a unique hierarchical nanostructure for water splitting.