▎ 摘　　要

In the past a few decades, electro-catalytic hydrogen evolution reaction (HER) has been demonstrated to be an efficient method for production of clean hydrogen sources, and the central task is seeking for a low-cost and high-efficient catalyst. In this work, a carbon nanotubes (CNTs) encapsulated cobalt-cobalt phosphide on reduced graphene oxides material (Co-Co2P@CNT/rGO) was engineered via a simple high-temperature phosphating process. The as-gained catalyst was well-characterized, and we found that the metallic Co is essential to the formation of CNTs. Additionally, the catalyst was further employed in HER process. Compared with the metallic cobalt-free sample (Co2P@C/rGO), the Co-Co2P@CNT/rGO showed a significantly boosted HER activity with a Tafel slope of 55.43 mV dec(-1) and an exchange current density of 5.62 x 10(-3) mA cm(-2). Besides, owing to the confining effect of CNTs, the Co-Co2P@CNT/rGO showed excellent stability during the 20 h stability test. (C) 2019 Published by Elsevier Ltd.