Activation Strategy of WS2 as an Efficient Photocatalytic Hydrogen Evolution Cocatalyst through Co2+ Doping to Adjust the Highly Exposed Active (100) Facet

Abstract

As an effective method to improve the surface catalytic activity of catalysts, crystal plane engineering has become a research hot spot in recent years. Doping regulation of the highly exposed facet with low surface energy is helpful to expand their applications in the field of photocatalysis. Therefore, low concentration transition metal ions (Co2+) in the high exposure surface (100) of WS2 by one‐pot hydrothermal method are doped. Moreover, density functional theory (DFT) calculation shows that after Co2+ in WS2 (100) crystal replaces W4+, the surface charge is rearranged, and the local charge near Co2+ is enhanced, which accelerates the electron transfer rate, makes the electron transfer rapidly to (100) facet through the secondary transfer process, and finally promotes proton reduction. Therefore, the hydrogen production efficiency of 7% (Co–WS2)/Cd0.4Zn0.6S (CZS) Schottky junction (21 000 μmol g−1 h−1) is 9.3 times and 1.3 times higher than that of CZS (2265 μmol g−1 h−1) and 7% WS2/CZS heterojunction (17 000 μmol g−1 h−1). This study has certain reference and guiding significance for the study of new cocatalysts, not only on pristine semiconductor but also for semiconductor‐based hybrid structures.