Highly Efficient Hydrogen Evolution from Seawater by Biofunctionalized Exfoliated MoS₂ Quantum Dot Aerogel Electrocatalysts That Is Superior to Pt

Abstract

As a source of clean and sustainable energy, reliable hydrogen production requires highly efficient and stable electrocatalysts. In recent years, molybdenum disulfide (MoS₂) has been demonstrated as a promising electrocatalyst for hydrogen evolution reactions (HERs). Here, we demonstrate that a three-dimensional (3D) MoS₂ quantum dot (MoS₂QD) aerogel is an efficient cathode electrocatalyst that can be used to enhance the HER in acid, neutral, and alkaline (e.g., real seawater) environments. In studying the effects of the exfoliated MoS₂ dimension for the HER, we found that the biofunctionalized exfoliated MoS₂QD shows much higher cathodic density, a more lower energy input, and a lower Tafel slope for the HER than the larger size of the chlorophyll-assisted exfoliated MoS₂, highlighting the importance of the size of the MoS₂ aerogel support for accelerating the HER performance. Moreover, the electrocatalytic activity of MoS₂QD-aerogel is superior to that of Pt in neutral conditions. In real seawater, the MoS₂QD-aerogel sample exhibits stable HER performance after consecutive scanning for 150 cycles, while the HER activity of the Pt dramatically decreases after 50 cycles. These results showed for the first time how the 3D MoS₂ configuration in MoS₂ aerogel can be used to effectively produce hydrogen for clean energy applications.