Transforming Damage into Benefit: Corrosion Engineering Enabled Electrocatalysts for Water Splitting

Abstract

Producing high‐purity hydrogen from water electrocatalysis is essential for the flourishing hydrogen energy economy. It is of critical importance to develop low‐cost yet efficient electrocatalysts to overcome the high activation barriers during water electrocatalysis. Among the various approaches of catalyst preparation, corrosion engineering that employs the autogenous corrosion reactions to achieve electrocatalysts has emerged as a burgeoning strategy over the past few years. Benefiting from the advantages of simple synthesis, effective regulation, easy scale‐up production, and extremely low cost, corrosion engineering converts the harmful corrosion process into the useful catalyst preparation, achieving the goal of “transforming damage into benefit.” Herein, the concept of corrosion engineering, fundamental reaction mechanisms, and affecting factors are firstly introduced. Then, recent progresses on corrosion engineering for fabricating electrocatalysts toward water splitting are summarized and discussed. Specific attentions are devoted to the formation mechanisms, catalytic performances, and structure–activity relations of these catalysts as well as the approaches employed for performance improvements. At last, the current challenges and future exploiting directions are proposed for achieving highly active and durable electrocatalysts. It is envisioned to shed light on the multidisciplinary corrosion engineering that is closely associated with corrosion and material science for energy and environmental applications.

NiFe Layered Double Hydroxides Grown on a Corrosion‐Cell Cathode for Oxygen Evolution Electrocatalysis

“…[17] Therefore, the AIEA of NiFe-LDH@IF-c-t (Figure 7d) decreases due to the decrease of the Fe 2+ -doping level of NiFe-LDH nanosheets as c increases. [17] With the decrease of both the ECSA (Figure 7c) and AIEA (Figure 7d), the AEA of NiFe-LDH@IF-c-t decreases as c increases (Figure 7a) according to the expression (8).…”

“…Among these methods, corrosion engineering is more promising due to the absence of intentional energy input, mild reaction conditions, simple instruments, and high scalability. [ 8 ] By adjusting the substrate and corrosion solution, various self‐supported LDH can be obtained via corrosion engineering. Self‐supported NiCo‐LDH, [ 9 ] NiCoRu‐LDH, [ 9b ] and NiFe‐LDH [ 10 ] were prepared by the corrosion of nickel foam in CoCl 2 , CoCl 2 &RuCl 3 , and FeCl 2 or Fe(NO 3 ) 3 solution, respectively.…”

“…[11] For example, Liu reported that the NiFe-LDH@IF required only 340 mV to reach 1000 mA cm -2 where it remained stable for more than 6000 h. [7a] This is the best reported electrocatalytic stability so far. [8] However, the further optimization of the growth and electrocatalytic performance of the NiFe-LDH@IF is hindered by some fundamental issues. Based on previous reports, the growth mechanism of the NiFe-LDH@IF remains controvers ial, [7a,8,11c,12] and the growth process is still unclear.…”

Rational Design of Superior Electrocatalysts for Water Oxidation: Crystalline or Amorphous Structure?

“…The molecular structure with long‐range ordering feature is defined as crystalline structure (Figure 1a). Many efficient strategies can be applied to moderate the physicochemical properties of crystalline structures, such as phase engineering (including some special phases), [ 27–29 ] defect chemistry, [ 30,31 ] corrosion engineering, [ 32,33 ] strain engineering, [ 34,35 ] and many other methodologies. [ 8,36 ] Generally, initial crystalline materials could maintain crystallinity or become partially amorphous during/after the OER (Figure 1d,e and Table 1), which is determined by the initial physicochemical properties of the crystalline materials.…”

Scalable Synthesis of NiFe‐LDH/Ni9S8/NF Nanosheets by Two‐Step Corrosion for Efficient Oxygen Electrocatalysis

“…Corrosion engineering, which mainly bases on the spontaneous redox reaction process, is regarded as an autogenous phenomenon in ambient environment according to the previous researches [18] . Hence, a new opportunity appears to construct electrocatalysts with low cost and simple procedure, which makes the scalable fabrication and practical application possible [19] .…”