Performance and Mechanism of Photoelectrocatalytic Activity of MoSx/WO3 Heterostructures Obtained by Reactive Pulsed Laser Deposition for Water Splitting

Nanomaterials

Oxana Rubinkovskaya¹  Alexey Soloviev¹  Roman Romanov¹  Dmitry Fominski¹  Vyacheslav Fominski¹  Maxim Demin²  Ksenia Maksimova²  Pavel Shvets²  Aleksandr Goikhman² 

[1] National Research Nuclear University MEPhI (Moscow Engineering Physics Institute), Kashirskoe Sh. 31, 115409 Moscow, Russia;REC “Functional Nanomaterials”, Immanuel Kant Baltic Federal University, Aleksandra Nevskogo St. 14, 236041 Kaliningrad, Russia;

关键词: reactive pulsed laser deposition;    molybdenum sulfides;    tungsten oxide;    photocatalysis;    heterostructure;    water splitting;   

DOI  :  10.3390/nano10050871

来源: DOAJ

【 摘 要 】

This work studies the factors that affect the efficiency of the photoelectrochemical hydrogen evolution reaction (HER) using MoS_x/WO₃ nano-heterostructures obtained by reactive pulsed laser deposition (RPLD) on glass substrates covered with fluorinated tin oxide (FTO). Another focus of the research is the potential of MoS_x nanofilms as a precursor for MoO_z(S) nanofilms, which enhance the efficiency of the photo-activated oxygen evolution reaction (OER) using the MoO_z(S)/WO₃/FTO heterostructures. The nanocrystalline WO₃ film was created by laser ablation of a W target in dry air at a substrate temperature of 420 °C. Amorphous MoS_x nanofilms (2 ≤ x ≤ 12) were obtained by laser ablation of an Mo target in H₂S gas of varied pressure at room temperature of the substrate. Studies of the energy band structures showed that for all MoS_x/WO₃/FTO samples, photo-activated HER in an acid solution proceeded through the Z-scheme. The highest photoelectrochemical HER efficiency (a photocurrent density ~1 mA/cm² at a potential of ~0 V under Xe lamp illumination (~100 mW/cm²)) was found for porous MoS_4.5 films containing the highest concentration of catalytically active sites attributed to S ligands. During the anodic posttreatment of porous MoS_x nanofilms, MoO_z(S) films with a narrow energy band gap were formed. The highest OER efficiency (a photocurrent density ~5.3 mA/cm² at 1.6 V) was detected for MoO_z(S)/WO₃/FTO photoanodes that were prepared by posttreatment of the MoS_x~3.2 precursor. The MoO_z(S) film contributed to the effective photogeneration of electron–hole pairs that was followed by the transport of photoelectrons from MoO_z(S) into the WO₃ film and the effective participation of holes possessing strong oxidation ability in the OER on the surface of the MoO_z(S) film.

【 授权许可】

Unknown