Economical, efficient and stable single photo-catalysts are vital for realizing enhanced photo-catalytic H-2 evolution activity. In this study, we report two n-type single transition metal phosphide with excellent photo-catalytic activity under visible light irradiation, which is of great significance for the discovery and synthesis of novel and more efficient photo-catalysts. And completely controllable synthesis will greatly reduce application costs. Furthermore, the fairly high activity of H-2 evolution of the resulting catalysts having low crystallinity and extremely strong optical properties is reveled in detail via investigating the dynamics of hydrogen generation of CoP and WP. Moreover, it is found that CoP and WP have low band-gap energy and increased optical absorption properties through studies. Meanwhile, low crystallinity state for they also is get by XRD technology. These may be the main reasons why CoP and WP exhibit efficient H-2 evolution activity. In addition, the possible mechanism showing high photocatalytic activity of hydrogen evolution for CoP and WP is proposed by a series of other characterizations, such as SEM, TEM, XPS, BET, transient photo-current response, steady-state fluorescence, transient-state fluorescence and Mott-Schottky studies etc. (C) 2019 Elsevier Inc. All rights reserved.