Recent advances in defect electrocatalysts: Preparation and characterization

Recent Progress on Defect‐rich Transition Metal Oxides and Their Energy‐Related Applications

“…On the basis of the dimensionality, TMO crystal defects can be divided into point defects (0D defects), line defects (1D defects), plane defects (2D defects) and volume defects (3D defects) ( Figure 2). [39,40] Different types of defects are prepared using different synthesis strategies and show different properties. atoms is partially destroyed, while the electronic state is changed.…”

“…These unique sites caused by defects play very important roles for metal-air batteries, fuel cells, photocatalysts, and electrocatalysts. [40,47,48] Recently, many methods used for defect formation have been developed: heteroatom doping, solution treatment, annealing treatment, template synthesis, plasma etching etc.…”

“…The defects can be built in the crystals during their growth, or can be produced by post‐processing (high temperature, high pressure, and plasma etching). These unique sites caused by defects play very important roles for metal‐air batteries, fuel cells, photocatalysts, and electrocatalysts [40,47,48] . Recently, many methods used for defect formation have been developed: heteroatom doping, solution treatment, annealing treatment, template synthesis, plasma etching etc.…”

Defect Engineering of Molybdenum-Based Materials for Electrocatalysis

“…The currently reported synthesis strategies for defective catalysts are still difficult to control for specific types of defects [108]. Therefore, the majority of the defective electrocatalysts reported in the literature contain more than one type of defects, especially for multidimensional defects [109]. For example, Zhang et al used arc melting to synthesize Mo oxide with various defects, in which the intensity of A-MoS 2 (after arc smelting) was significantly reduced in the PL spectrum, highlighting the formation of defects and cracks in MoS 2 [63].…”

A Resol‐Assisted Cationic Coordinative Co‐assembly Approach to Mesoporous ABO3 Perovskite Oxides with Rich Oxygen Vacancy for Enhanced Hydrogenation of Furfural to Furfuryl Alcohol

“…Until to now,w idely used methods to conduct oxygen defects into perovskite oxides mainly involve thermal annealing under vacuum or inert atmosphere or hydrogen gas,w et chemical reduction method, and some means of porous engineering and reducing size of samples. [16][17][18][19][20] Commonly, crystalline perovskite oxides are obtained via high temperature calcination treatment, causing products with dense structure composed of large particles,i nferior surface reactivity even compromised catalytic activity.F rom the perspective of these issues,the construction of porous architecture of perovskite oxide catalyst is considered to be an effective way to overcome above problems and provide opportunities for boosting catalytic activity.M oreover,p orous ABO 3 perovskite oxide composed of functional nanocrystalline framework will hold as ignificant advantage for providing oxygen defect sites to promote catalytic activity.However,until now it is still ahuge challenge to construct mesoporous perovskite oxides by molecular assembly methods, [21][22][23] owing to the following issues.F irst, the synthesis system is complicated in terms of dynamics because it includes multifarious metal precursors,a dditives,a nd block copolymers.S trictly controlling of reaction condition is generally required to regulate coassembly process between inorganic precursors and block copolymer to avoid phase separation, owing to their complicated hydrolysis and condensation nature. [24][25][26][27] Furthermore, thermodynamically,ahigh-temperature (> 500 8 8C) calcination is necessary to drive organic-inorganic composite to crystallize into perovskite oxides.H owever,t he mesostructures tend to collapse and agglomeration during high-temperature crystallization process,i tw ill result in poor porous structure and low thermal stability of perovskite oxides.…”