Electrochemical water splitting plays an important role in alternative energy studies, since it is highly efficient and environment-friendly. Accordingly, it is an ideal way of providing alternative to meet the urgent need of finding sustainable and clean energy. This study presents the fabrication of CoP attached on multilevel N-doped CNT/graphene (CoP-CNT/NG) hybrids. The multilevel carbon structure can enhance electrical conductivity efficiently and increase the reaction active area immensely. The obtained electrocatalyst exhibits great electronic conductivity (17.8 s cm(-1)) and HER activity with low overpotential (155 mV at 10 mA cm(-2)), low Tafel slope (69.1 mV dec(-1)) in 0.5 M H2SO4. In addition, the CoP-CNT/NG displays prominent electrochemical durability after 18 h. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.