defect engineering
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2022 ◽  
Vol 429 ◽  
pp. 132157
Shi-Qing Wang ◽  
Xu Gu ◽  
Xinzhu Wang ◽  
Xiao-Yu Zhang ◽  
Xiao-Yao Dao ◽  

2022 ◽  
Woochang Kim ◽  
Wonseok Lee ◽  
Seung-Mo Lee ◽  
Duckjong Kim ◽  
Jinsung Park

Abstract We propose a method of improving the thermoelectric properties of graphene using defect engineering through plasma irradiation and atomic layer deposition (ALD). We intentionally created atomic blemishes in graphene by oxygen plasma treatment and subsequently healed the atomistically defective places using Pt-ALD. After healing, the thermal conductivity of the initially defective graphene increased slightly, while the electrical conductivity and the square of the Seebeck coefficient increased pronouncedly. The thermoelectric figure of merit of the Pt-ALD treated graphene was measured to be over 4.8 times higher than the values reported in the literature. We expect that our study could provide a useful guideline for the development of graphene-based thermoelectric devices.

2022 ◽  
Vol 11 (2) ◽  
pp. 283-294
Zhipeng Li ◽  
Dong-Xu Li ◽  
Zong-Yang Shen ◽  
Xiaojun Zeng ◽  
Fusheng Song ◽  

AbstractLead-free bulk ceramics for advanced pulsed power capacitors show relatively low recoverable energy storage density (Wrec) especially at low electric field condition. To address this challenge, we propose an A-site defect engineering to optimize the electric polarization behavior by disrupting the orderly arrangement of A-site ions, in which $${\rm{B}}{{\rm{a}}_{0.105}}{\rm{N}}{{\rm{a}}_{0.325}}{\rm{S}}{{\rm{r}}_{0.245 - 1.5x}}{_{0.5x}}{\rm{B}}{{\rm{i}}_{0.325 + x}}{\rm{Ti}}{{\rm{O}}_3}$$ Ba 0.105 Na 0.325 Sr 0.245 − 1.5 x □ 0.5 x Bi 0.325 + x TiO 3 ($${\rm{BN}}{{\rm{S}}_{0.245 - 1.5x}}{_{0.5x}}{{\rm{B}}_{0.325 + x}}{\rm{T}}$$ BNS 0.245 − 1.5 x □ 0.5 x B 0.325 + x T , x = 0, 0.02, 0.04, 0.06, and 0.08) lead-free ceramics are selected as the representative. The $${\rm{BN}}{{\rm{S}}_{0.245 - 1.5x}}{_{0.5x}}{{\rm{B}}_{0.325 + x}}{\rm{T}}$$ BNS 0.245 − 1.5 x □ 0.5 x B 0.325 + x T ceramics are prepared by using pressureless solid-state sintering and achieve large Wrec (1.8 J/cm3) at a low electric field (@110 kV/cm) when x = 0.06. The value of 1.8 J/cm3 is super high as compared to all other Wrec in lead-free bulk ceramics under a relatively low electric field (< 160 kV/cm). Furthermore, a high dielectric constant of 2930 within 15% fluctuation in a wide temperature range of 40–350 °C is also obtained in $${\rm{BN}}{{\rm{S}}_{0.245 - 1.5x}}{_{0.5x}}{{\rm{B}}_{0.325 + x}}{\rm{T}}$$ BNS 0.245 − 1.5 x □ 0.5 x B 0.325 + x T (x = 0.06) ceramics. The excellent performances can be attributed to the A-site defect engineering, which can reduce remnant polarization (Pr) and improve the thermal evolution of polar nanoregions (PNRs). This work confirms that the $${\rm{BN}}{{\rm{S}}_{0.245 - 1.5x}}{_{0.5x}}{{\rm{B}}_{0.325 + x}}{\rm{T}}$$ BNS 0.245 − 1.5 x □ 0.5 x B 0.325 + x T (x = 0.06) ceramics are desirable for advanced pulsed power capacitors, and will push the development of a series of Bi0.5Na0.5TiO3 (BNT)-based ceramics with high Wrec and high-temperature stability.

Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 487
Yang Zhang ◽  
Wanbo Qu ◽  
Guyang Peng ◽  
Chenglong Zhang ◽  
Ziyu Liu ◽  

Aberration-corrected scanning transmission electron microscopy (AC-STEM) has evolved into the most powerful characterization and manufacturing platform for all materials, especially functional materials with complex structural characteristics that respond dynamically to external fields. It has become possible to directly observe and tune all kinds of defects, including those at the crucial atomic scale. In-depth understanding and technically tailoring structural defects will be of great significance for revealing the structure-performance relation of existing high-property materials, as well as for foreseeing paths to the design of high-performance materials. Insights would be gained from piezoelectrics and thermoelectrics, two representative functional materials. A general strategy is highlighted for optimizing these functional materials’ properties, namely defect engineering at the atomic scale.

ChemSusChem ◽  
2022 ◽  
Xiang Li ◽  
Likang Zhang ◽  
Qiang Deng ◽  
Shixia Chen ◽  
Jun Wang ◽  

2022 ◽  
Caiting Feng ◽  
Panfeng Wu ◽  
Qinlong Li ◽  
Jiquan Liu ◽  
Danjun Wang ◽  

Photo-driven nitrogen fixation involves the activation and hydrogenation processes of molecular nitrogen at the surface of photocatalyst in producing ammonia. Herein, significantly enhancement of catalytic efficiency is achieved via constructing...

2022 ◽  
Haiping Zhang ◽  
Ke Wang ◽  
Hui Wang ◽  
Hongfei Lin ◽  
Ying Zheng

2022 ◽  
pp. 134624
Jie Lei ◽  
Chaofeng Wang ◽  
Xiaobo Feng ◽  
Liang Ma ◽  
Xiangmei Liu ◽  

Xu Zhang ◽  
Peijie Ma ◽  
Cong WANG ◽  
Li-Yong Gan ◽  
Xianjie Chen ◽  

Defect engineering modified graphite carbon nitride (g-C3N4) has been widely used in various photocatalytic systems due to the enhanced catalytic activity by multiple defect sites (such as vacancies or functional...

Wibawa Hendra Saputera ◽  
Tze Hao Tan ◽  
Emma Catherine Lovell ◽  
Aditya Rawal ◽  
Kondo-Francois Aguey-Zinsou ◽  

Binary TiO2/SiO2 oxides were synthesized via flame spray pyrolysis as supports for a Pt catalyst. The effect of the mole ratio of the silica and on the catalyst characteristics and...

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