Modulated electrochemical oxygen evolution catalyzed by MoS₂ nanoflakes from atomic layer deposition

Abstract

Electrochemical water splitting into H 2 and O 2 has attracted wide attention owing to the urgent need for clean and renewable energy sources. However, the scarcity and high-cost limit the large-scale application of noble metal catalysts such as IrO 2 and RuO 2 . In this work, as a lowcost catalyst for the electrochemical O 2 evolution reaction (OER), MoS 2 nanoflakes were obtained by atomic layer deposition (ALD) using MoCl 5 and H 2 S on carbon fiber paper surface. According to the results of electrochemical measurements, the MoS 2 nanoflakes exhibit an excellent catalytic activity, and the activity can be modulated by controlling the density and the internal resistance of MoS 2 nanoflakes. Moreover, the plasma treatment can further improve the activity of MoS 2 nanoflakes, and the reason was discussed through the measurements of contact angle, electrochemical impedance spectroscopy, and electrochemically active surface area. The MoS 2 nanoflakes obtained by ALD possess huge values for electrochemical OER as a catalyst.

Atomic Layer Deposition of 2D Metal Dichalcogenides for Electronics, Catalysis, Energy Storage, and Beyond

“…Nevertheless, these studies have shown highly promising results that are comparable to the best MoS 2 and other nonplatinum metal OER catalysts reported in literature (see refs. [190,331] and references therein), therefore motivating further studies on the subject.…”

“…Biosensor [188] 400 tens of nm rough film (cryst.) Biosensor [189] 450 ≈5-50 nm rough films (≈10-20 nm) OER [190] 390-470 1-3 ML flakes (≈50-400 nm) 4-5 ML films (≈400 nm) - [119] 250-325 20−70 nm rough films (10-100 nm) HER 2017 [191] 150-300 5-50 nm rough films (10-300 nm) LIB, NIB [192] 250-300 ≈5-70 nm rough films (10-50 nm) PEC [193] 250 ≈20 nm rough film (≈10-20 nm) PEC [194] 250 ≈7-30 nm rough film (≈10-30 nm) PEC [195] 200-420 1-8 ML films (10-25 nm) FET [196] MoCl 5 + S(SiMe 3 ) 2 375 (800, S) 8 ML film (as-dep. amorp., ann.…”

“…The authors reported an η 10 of 270 mV, which is 200 mV lower compared to the bare Co foam, along with an improved long-term stability. Huang et al [190] deposited MoS 2 on carbon fiber paper at 450 °C using MoCl 5 and H 2 S. Optimal performance, namely, an η 10 of 311 mV and a Tafel slope of 66 mV dec −1 was obtained using an ≈30 nm thick MoS 2 film. A 20 s postdeposition plasma treatment (atmosphere not specified) decreased the η 10 and Tafel slope to 273 mV and 61 mV dec −1 , respectively.…”

“…[352] for definitions of different metrics. 2019 [190] Mo(CO) 6 + H 2 S 200 ? nm rough films (≈5 nm) Co foam c) 270 74 2017 [207] a)…”

Atomic‐Layer‐Deposition‐Based 2D Transition Metal Chalcogenides: Synthesis, Modulation, and Applications

“…[70] MoS 2 layered nanoflakes were prepared using MoCl 5 and H 2 S on carbon fiber paper (CFP) at 450 °C. [71] The MoS 2 uniformly covered the CFP surface without bulk accumulation and its density increased with increasing number of ALD cycles. The film was S deficient (S/Mo ratio was 1.71) and amorphous (or had a low crystallinity).…”