Defect-Rich 2D Material Networks for Advanced Oxygen Evolution Catalysts

Abstract

A versatile and straightforward room-temperature strategy is demonstrated to synthesize boundary defect-rich ultrathin transition metal hydroxide nanosheet networks by in situ etching of a cobalt metal−organic framework (Co-MOF, ZIF-L-Co). The resultant defect-rich ultrathin Co(OH) 2 (D-U-Co(OH) 2 ) nanoarray is one of the most active monometal-based oxygen evolution catalysts to date. Its activity is 3−4 times higher than that of the commercial RuO 2 and superior to that of the reported exfoliated bimetallic catalysts. Co-MOF can also be grown on various substrates, and the chemical composition of the defect-rich 2D materials is tunable by changing the metal ions in the etchants. Owing to these merits of the unique synthesis route, our work provides an opportunity for synthesizing advanced nanomaterials that are difficult to get access to by conventional methods.

2D Materials Decorated with Ultrathin and Porous Graphene Oxide for High Stability and Selective Surface Activity

“…Ji-Soo Jang, Hong Ju Jung, Sanggyu Chong, Dong-Ha Kim 2D materials such as MXene, black phosphorus (BP), transition metal dichalco genides, and graphene oxide (GO) are viewed as exciting prospects for chemical sensing, [1] catalysis, [2] gas storage/separa tion, [3] and energy storage system, [4] owing to their inherent ultralarge surfaceto volume ratio, exceptional edgesite activi ties, tunable electrical properties, and mechanical flexibility. [4,5] Recently, such 2D materials have gained major recognition as surface active layers, taking advantage of their abundant, highly active adsorption sites, and fast charge transfer even at room temperature (RT).…”

Interface Electronic Coupling in Hierarchical FeLDH(FeCo)/Co(OH)2 Arrays for Efficient Electrocatalytic Oxygen Evolution

“…The resulting materials often exhibit high catalytic activity attributed to their abundant edges/defectso rc oordinatively unsaturated metal sites. [5,[26][27][28] Unfortunately,t he catalytic durability of the thusprepared 2D-TMHs cannot be maintained. To solve this problem, studies are devoted to constructing bi-or multimetallic hydroxides [15,20,[29][30][31] by partially replacingt he originalc ations in the crystal lattice by heterogeneous cations, which leads to speciali nteractionsa mong them.H owever,i nt his mutual doping method, it is hard to keep ab alance between the catalytic activity and stability.…”

“…[1][2][3][4] In particular, thin 2D-TMHs have advantages such as large surfacea rea and exposure of specials ites and/or defects compared to thick nanosheets. [5][6][7] Hence,t hin 2D-TMHs contribute to providinga bundant active sites and show much improved OER catalytic activity.M oreover,t hin 2D-TMHs with large surface area offer an enlarged solid/liquid interface, which enhances surfacea dsorption and desorption of reactants and products during the OER. [8][9][10][11] In addition, the thin structure of 2D-TMHs may be beneficial for shortening the diffusion length of intermediate speciesa nd boosting charge-transfera bility.…”

“…[8][9][10][11] In addition, the thin structure of 2D-TMHs may be beneficial for shortening the diffusion length of intermediate speciesa nd boosting charge-transfera bility. [5,12,13] Hence, thin 2D-TMHs are considered to be promising candidates for replacing Ru(Ir)O 2 noble-metal catalysts. [14,15] The synthesis of thin 2D-TMHs has traditionally relied on top-downe xfoliationa nd bottom-up hydrothermalm ethods.…”

In Situ Synthesis of Ultrathin Graphene‐Like Nanosheets as a Highly Effective Oxygen Catalyst for Zinc−Air Batteries

“…However, the practical utilization of precious catalysts are limited by the deficiency of resource, high cost and poor stability. Furthermore, either Pt/C or RuO 2 cannot simultaneously catalyze ORR and OER . To meet the needs of actual application, extensive researches have been made to seek for a highly active and durable non‐precious bifunctional electrocatalyst …”