Fe‐Based Mesoporous Nanostructures for Electrochemical Conversion and Storage of Energy

Abstract

Decarbonization of the global energy system requires a coordinated effort towards disruptive technology of renewable energy conversion and storage (ECS) that can be potential to secure and diversify energy systems by increasing efficiency of conversion and storage of intermittent energy sources. Porous nanostructures have been newly reported as a promising class of most effective materials for this purpose because of their unique advantages in terms of large surface‐to‐volume ratios, surface permeability, and void spaces. These offer abundant active sites for ultimate electrochemical activities by the shortening pathway of mass/charge transport. Particularly, Fe‐based mesoporous nanostructures (mp‐FeNSs) have been recently fascinating. Iron is a principal active center in nanocomposites and has high industrial suitability for next‐generation technology owing to its environment friendliness, abundance, and low cost. In this review, crucial technical advances related to mp‐FeNSs that have occurred during 2016–2020 are summarized in terms of synthesis, structural design strategy, and ECS applications such as water electrocatalysis, Li‐ion batteries, and supercapacitors. This review is supportive for potential readers to obtain general and professional information in this field since Fe‐based energy materials are exclusively introduced in the article including a fundamental understanding of electrochemistry and related technologies in detail.

Amorphous Ni1–xFex Oxyhydroxide Nanosheets with Integrated Bulk and Surface Iron for a High and Stable Oxygen Evolution Reaction

“…Several efforts have been devoted to develop an efficient OER catalyst based on earth-abound first-row transition metals − such as Ni, Co, and Fe with promising results using different approaches such as elemental doping, defect engineering, and morphology optimization . Among these materials, Ni with other transition metallic oxides and oxyhydrates, sulfides, and nitrides have been thoroughly investigated for OER catalysis owing to their remarkable catalytic performance. , …”

“…14 Among these materials, Ni with other transition metallic oxides and oxyhydrates, 15 sulfides, and nitrides 16 have been thoroughly investigated for OER catalysis owing to their remarkable catalytic performance. 17,18 Despite the enormous progress made so far, there is still a controversy on elucidating the actual role of Fe specifically with regard to its position within the main catalyst part. 19 It is well acknowledged that doping of Fe to Ni-based catalyst is a well-established means to improve their intrinsic activities toward OER catalysis.…”

Transition Metal-Based 2D Layered Double Hydroxide Nanosheets: Design Strategies and Applications in Oxygen Evolution Reaction

“…The as-generated LDH demonstrated a lower overpotential of 336 mV at a current density of 10 mA cm −2 and a Tafel slope as low as 30 mV dec −1 . Similar to Ni, Fe is also gaining attention as a potential catalyst for water electrolysis, owing to its abundance, low toxicity, and stability [ 36 ].…”

“…Furthermore, LDHs can be designed into a variety of structures, including single or few-layer nanosheets, exposing more active sites that, in turn, enhance their activity toward the OER [ 33 ]. Defects can be introduced through nanoscale porous engineering that enhances their OER performance by exposing the large number of electrochemically active sites [ 34 , 35 , 36 ]. Fewer active sites and poor electronic conductivity are the main challenges limiting the OER electrocatalytic performance of LDHs [ 37 , 38 , 39 ].…”

Electrochemical Investigation of Porosity in Core–Shell Magnetoplasmonic Nanoparticles

“…Core–shell nanoparticles (NPs) are of great scientific interest because of their unique features and broad applications in energy, electromagnetic shielding, catalysis, optoelectronics, sensors, drug delivery, and environmental remediation . Recent studies using porous shells have shown the advantages of large surface to volume ratios, permeability, void spaces, confinement ability of pore channels and cavities, and fast mass/charge transport . These properties usually offer an abundant electroactive site for chemical reaction and have potential applications in biomedicine and nanophotonics. , Moreover, an in-depth understanding of the reaction between the core surface and the surrounding environment helps a more efficient nanostructure to be fabricated for the desired application, where the surrounding environment may be a designated shell or solvent if the shell is porous.…”