The depletion of fossil fuels and rapidly increasing environmental concerns have urgently called for the utilization of clean and sustainable sources for future energy supplies. Hydrogen (H2) is recognized as a prioritized green resource with little environmental impact to replace traditional fossil fuels. Electrochemical water splitting has become an important method for large-scale green production of hydrogen. The hydrogen evolution reaction (HER) is the cathodic half-reaction of water splitting that can be promoted to produce pure H2 in large quantities by active electrocatalysts. However, the unsatisfactory performance of HER electrocatalysts cannot follow the extensive requirements of industrial-scale applications, including working efficiently and stably over long periods of time at high current densities (⩾1000 mA cm–2). In this review, we study the crucial issues when electrocatalysts work at high current densities and summarize several categories of strategies for the design of high-performance HER electrocatalysts. We also discuss the future challenges and opportunities for the development of HER catalysts.
the global energy and environmental issues. [1][2][3] Its half-reaction, oxygen evolution reaction (OER), is considered as the key bottleneck in water splitting owing to its multiple protons and electron transfer. [4,5] Through precious metal oxides such as IrO 2 and RuO 2 exhibit effective OER activity, the scarcity, high cost, and inferior stability hinder their widespread applications. [6] The development of highly active electrocatalysts based on earthabundant elements is a highly promising solution to above predicament. However, at present, few noble-metal-free electrocatalysts can meet the requirements of commercial alkaline water electrolysis: afford the current density of 1000 mA cm −2 with stable operation over 100 h. [7,8] Therefore, developing noble-metal-free electrocatalysts with high efficiency and outstanding durability at the large current densities is imperative yet challenging.Iron (Fe)-based materials, especially FeOOH, have recently drawn great attention as promising OER catalysts due to their abundance, cost-effectiveness, and environmental friendliness. [9][10][11] It is reported that the intrinsic activity of FeOOH for OER is higher than that of NiOOH and CoOOH. [12] Nevertheless, the OER performance of FeOOH is far from satisfactory DevelopingFeOOH as a robust electrocatalyst for high output oxygen evolution reaction (OER) remains challenging due to its low conductivity and dissolvability in alkaline conditions. Herein, it is demonstrated that the robust and high output Zn doped NiOOH-FeOOH (Zn-Fe x Ni (1−x) )OOH catalyst can be derived by electro-oxidation-induced reconstruction from the pre-electrocatalyst of Zn modified Ni metal/FeOOH film supported by nickel foam (NF). In situ Raman and ex situ characterizations elucidate that the pre-electrocatalyst undergoes dynamic reconstruction occurring on both the catalyst surface and underneath metal support during the OER process. That involves the Fe dissolution-redeposition and the merge of Zn doped FeOOH with in situ generated NiOOH from NF support and NiZn alloy nanoparticles. Benefiting from the Zn doping and the covalence interaction of FeOOH-NiOOH, the reconstructed electrode shows superior corrosion resistance, and enhanced catalytic activity as well as bonding force at the catalyst-support interface. Together with the feature of superaerophobic surface, the reconstructed electrode only requires an overpotential of 330 mV at a high-current-density of 1000 mA cm −2 and maintains 97% of its initial activity after 1000 h. This work provides an indepth understanding of electrocatalyst reconstruction during the OER process, which facilitates the design of high-performance OER catalysts.
2D transition metal dichalcogenides (TMDs) have attracted significant attention due to their unique physical properties. Chemical vapor deposition (CVD) is generally a promising method to prepare ideal TMDs films with...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.