Abstract
As a new zero-carbon energy with high calorific value, hydrogen has attracted extensive attention in recent years. In this work, multiwalled carbon nanotubes modified molybdenum sulfide and molybdenum oxide heterostructure (MWCNTs-MoS2-MoO3) was obtained via a simple hydrothermal method. The low band gap of 0.02MWCNTs-MoS2-MoO3 (1.15 eV) endowed a good near-infrared (NIR) light response. The conduction band position of 0.02MWCNTs-MoS2-MoO3 (?0.63 V vs. reversible hydrogen electrode (RHE)) was negative enough to produce hydrogen. Compared with pure MoS2, the formation of MoS2-MoO3 heterostructure and introduction of MWCNTs generated better photoelectrochemical activity and NIR irradiation improved photoelectrocatalytic (PEC) hydrogen evolution performance in wide pH range. The 0.02MWCNTs-MoS2-MoO3 had superior overpotential (68 mV @ 10 mA cm?2) and Tafel slope (56 mV dec?1) in acidic media. The NIR improved PEC hydrogen evolution activity of 0.02MWCNTs-MoS2-MoO3 in acidic media could be explained by Volmer-Heyrovsky mechanism. The presence of large amount of bridging S22? in 1 T/2 H phase MoS2 and the synergistic effect between MWCNTs and MoS2-MoO3 heterostructure made a joint effect on the photoelectrocatalytic hydrogen evolution reaction (HER). NIR irradiation could increase the charge transport rate. The introduction of MWCNTs and heterostructure formation could increase the charge transport rate and improve the electron and hole separation ability of 0.02MWCNTs-MoS2-MoO3 as well.
NSTL
Elsevier