One-Step Coating of a ZnS Nanoparticle/MoS₂ Nanosheet Composite on Supported ZnO Nanorods as Anodes for Photoelectrochemical Water Splitting

Abstract

ZnO-based photoanodes absorb a limited spectrum of light, and their photogenerated electrons and holes combine easily. Such features limit their photoelectrochemical activity. Herein, we report the synthesis of ternary heterostructures comprising ZnO nanorods (NRs) and ZnS nanoparticles wrapped in MoS 2 nanosheets (ZnO/ZnS/MoS 2 , ZSM) directly grown on a substrate by a low-cost hydrothermal route and their performance as anodes for photoelectrochemical water splitting. The ZSM heterostructures exhibit a sixfold photocurrent density of 0.72 mA cm −2 , a fourfold maximum applied bias photonto-current efficiency of 0.28% compared to bare ZnO NRs, and excellent photostability. These improvements in the overall photoelectrochemical activity are due to enhanced light absorption in the visible light range, higher surface active sites, and efficient charge separation enabled by the introduction of a ZnS/MOS 2 coating. Our study demonstrates an alternative architecture design of ternary heterostructures with increased photoelectrochemical activity. In general, this approach of constructing a double heterojunction can also be extended to other materials with similar architectures.

MoSe2 Quantum Dots Enhance the Performance of ZnO Nanostructure-Based UV Photodetectors

“…The overall fabrication steps of the heterostructures are illustrated in Scheme . ZnO NRs were grown on commercial interdigitated indium tin oxide (ITO)-coated glass substrates (S161 Ossila, U.K.) via a hydrothermal method. , In detail, the substrates were initially heated at 450 °C in air, followed by a 10 min spraying of 0.2 M solution of zinc acetate dihydrate (Zn­(CH 3 COO) 2 ·2H 2 O, Merck) in deionized water using an ultrasonic nebulizer (GEA 204 AI, 1.7 MHz) to form a ZnO seed layer. After that, the substrates underwent annealing at 450 °C in air for 1 h. Subsequently, the substrates were immersed in a mixture containing 5 mL of 0.05 M zinc nitrate tetrahydrate (Zn­(NO 3 ) 2 ·4H 2 O, Merck) and 5 mL of 0.05 M hexamethylenetetramine ((CH 2 ) 6 N 4 , Merck), diluted in deionized water.…”

Advances in Hierarchical Inorganic Nanostructures for Efficient Solar Energy Harvesting Systems

“…Ananta R. Fareza et al [176] have rationally designed the ternary nanocomposite photoanode consisting of three different crystal phases such as hexagonal ZnO, cubic ZnS, and hexagonal MoS 2 . In this work, authors have initially grown ZnO nanorods on FTO substrate, then it was subjected to hydrothermal treatment to produce the ZnS/MoS 2 heterostructures.…”

MoS2 thin film decorated TiO2 nanotube arrays on flexible Ti foil for solar water splitting application

“…MoS 2 has an indirect band gap of 1.2 eV in bulk and converts into a direct band gap of ∼1.7-1.8 eV by reducing to a monolayer or a few layers which offers more reaction sites by exposing large surface area [18]. The suitable band edge position and smaller bandgap make it a suitable material to harvest the maximum part of visible light [19]. Various MoS 2 -based heterostructures such as MoS 2 /ZnO, MoS 2 /Bi 2 Se 3 , MoS 2 /WSe 2 , MoS 2 /CdTe, etc have been explored which showed excellent performance towards water splitting [20][21][22][23].…”