Search

• P-doped MoS 2 was integrated on Si pyramids as photocathode for hydrogen evolution. • The Efficiency was enhanced by exposing edges and activating basal planes of MoS 2. • MoS 1.75 P 0.25 /Si pyramids showed the optimal current density of −23.8 mA cm−2. • MoS 1.75 P 0.25 /2 nm TiO 2 /Si electrode presented the current retention of 84.0%. Herein, molybdenum disulfide (MoS 2) integrated on Si pyramids was used as a co-catalyst to improve charge separation efficiency. Various quantities of phosphorus (P) heteroatoms were doped into MoS 2 materials to boost catalytic performance. Raman and extended X-ray absorption fine structure spectra showed that the introduction of P dopants increased the number of exposed edges and sulfur vacancies that acted as hydrogen evolution reaction (HER) active sites on MoS 2 and enhanced photoelectrochemical activity. Density functional theory calculations revealed that the HER inert basal plane of MoS 2 became catalytically active after P atoms doping. MoS 1.75 P 0.25 /Si pyramids presented the optimal onset potential of +0.29 V (vs. RHE) and current density −23.8 mA cm−2. A titanium dioxide (TiO 2) layer was prepared through atomic layer deposition and served as a passivation layer that improved photocathode stability. The photocurrent retention of MoS 1.75 P 0.25 /10 nm TiO 2 /Si pyramids was 84.0% after 2 h of chronoamperometric measurement. [ABSTRACT FROM AUTHOR]