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Your search keyword '"Zhu, Kai"' showing total 212 results
Start Over Author "Zhu, Kai" Publisher american chemical society
212 results on '"Zhu, Kai"'

2. P–Cu2O QDs/Sn:α-Ga2O3 Nanorod Array for High-Sensitivity and Fast-Speed Solar-Blind Photodetectors.

Author

Han, Peipei, Chen, Zhiyuan, Zhu, Kai, Chen, Wenhui, Yang, Jizhou, Wan, Zhi, Teng, Feng, Hu, Peng, and Fan, Haibo

Abstract

Self-powered solar-blind detectors have important potential applications in military and civil fields, but their low responsivity and slow response speed limit their practical applications. Regulating the internal barrier height by doping is an effective means of optimizing the performance of self-powered detectors. In this work, a self-powered solar-blind detector with a Cu2O QDs/Sn:α-Ga2O3 nanorod array with an average diameter of 200–500 nm was prepared by a hydrothermal process and simple spin coating. In the absence of electrical power, the responsivity of the device reached 6.574 mA/W at a 254 nm light stimulation, which increased by 11.27 times that of the undoped photodetector. At the same time, the device also has a short optical response time of 0.2s/0.3s. These results can be attributed to the following reasons. (1) Sn doping increases the carrier concentration, thereby increasing the conductivity of α-Ga2O3. (2) In the interfacial depletion region of Cu2O QDs/Sn:α-Ga2O3, increasing the height of the built-in barrier can effectively separate the photogenerated electron–hole pairs. This work provides a simple and effective way to construct a high-performance self-powered solar-blind photodetector. [ABSTRACT FROM AUTHOR]

Published
2024
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21. Hybrid Co/CoO/Ce-Doped WO3 Nanoparticles on a ZIF‑L Framework as Bifunctional Oxygen Electrocatalysts for Rechargeable Zinc–Air Batteries.

Author

Zhang, Yan, Ma, Xiaoyue, Zhu, Kai, Wang, Jingwen, Cheng, Zhendong, Li, Ge, Yang, Lin, and Bai, Zhengyu

Abstract

The rational design of multiphasic interfaces is an efficient way to fabricate favorable catalysts for bifunctional oxygen reduction and oxygen evolution reactions (ORR/OER). Herein, the hybrid metallic nanoparticles composed of Co, CoO, and Ce-doped WO3 are anchored on the external surface of the preprepared catalysts (PZF-2-700) by pyrolyzing a unique polyoxometalate (POM)-containing metal–organic framework (MOF) precursor. The multiple heterointerfaces in the PZF-2-700 material surface provide defects as the catalytic active sites for the OER. Besides, the Co and CoO with Co–N–C, N–C, and Co–O in PZF-2-700 afford efficient catalytic performance for the ORR. Furthermore, the strong built-in field of PZF-2-700 enables the heterointerfaces with opposite charges and facilitates the electron transfer capacity throughout the structure. Based on this, the produced PZF-2-700 exhibits a small potential gap of 679 mV between the ORR and the OER. The homemade zinc–air battery (ZAB) with PZF-2-700 as the cathode catalyst displays a power density of 146.9 mW cm–2 and a charge/discharge cycling stability for 311 h with a charge–discharge period of 10 min, which offers a promising cathode catalyst for environment-friendly ZABs. [ABSTRACT FROM AUTHOR]

Published
2023
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28. Atomically Resolved Electrically Active Intragrain Interfaces in Perovskite Semiconductors

Author

Cai, Songhua, Dai, Jun, Shao, Zhipeng, Rothmann, Mathias Uller, Jia, Yinglu, Gao, Caiyun, Hao, Mingwei, Pang, Shuping, Wang, Peng, Lau, Shu Ping, Zhu, Kai, Berry, Joseph J., Herz, Laura M., Zeng, Xiao Cheng, Zhou, Yuanyuan, Cai, Songhua, Dai, Jun, Shao, Zhipeng, Rothmann, Mathias Uller, Jia, Yinglu, Gao, Caiyun, Hao, Mingwei, Pang, Shuping, Wang, Peng, Lau, Shu Ping, Zhu, Kai, Berry, Joseph J., Herz, Laura M., Zeng, Xiao Cheng, and Zhou, Yuanyuan

Abstract

Deciphering the atomic and electronic structures of interfaces is key to developing state-of-The-Art perovskite semiconductors. However, conventional characterization techniques have limited previous studies mainly to grain-boundary interfaces, whereas the intragrain-interface microstructures and their electronic properties have been much less revealed. Herein using scanning transmission electron microscopy, we resolved the atomic-scale structural information on three prototypical intragrain interfaces, unraveling intriguing features clearly different from those from previous observations based on standalone films or nanomaterial samples. These intragrain interfaces include composition boundaries formed by heterogeneous ion distribution, stacking faults resulted from wrongly stacked crystal planes, and symmetrical twinning boundaries. The atomic-scale imaging of these intragrain interfaces enables us to build unequivocal models for the ab initio calculation of electronic properties. Our results suggest that these structure interfaces are generally electronically benign, whereas their dynamic interaction with point defects can still evoke detrimental effects. This work paves the way toward a more complete fundamental understanding of the microscopic structure-property-performance relationship in metal halide perovskites. ©

Published
2022

44. Pt Nanoparticle-Modified SnO2–ZnO Core–Shell Nanosheets on Microelectromechanical Systems for Enhanced H2S Detection.

Author

Wu, Xue-Yan, Zhu, Li-Yuan, Sun, Jie, Zhu, Kai-Yue, Miao, Xiao-Yong, Liu, Meng-Yang, Zhao, Xue-Feng, and Lu, Hong-Liang

Abstract

Pt nanoparticle (NP)-modified SnO2–ZnO (SnO2–ZnO–Pt) core–shell nanosheets (NSs) for hydrogen sulfide (H2S) gas sensing were successfully synthesized via atomic layer deposition, hydrothermal method, and magnetron sputtering. More importantly, the SnO2–ZnO–Pt NS sensing materials were synthesized in situ on microelectromechanical system (MEMS) devices, which are expected to be high-performance gas sensors with superior sensitivity, great selectivity, good reproducibility, and low power consumption. To be specific, the SnO2–ZnO–Pt NSs displayed a high sensitivity (Ra/Rg) of 30.43 and an excellent selectivity when detecting 5 ppm H2S at an operating temperature of 375 °C. Their rate of resistance change was 29.43, which was about 24 and 9 times those of the pristine SnO2 NS (∼1.25) and SnO2–ZnO core–shell NS (∼3.43) sensors, respectively. These substantially improved sensing properties could be mainly attributed to the formation of heterojunctions, catalytic sensitization effect, and increased specific surface area of Pt NP modification. Thus, the proposed SnO2–ZnO–Pt NS gas sensors demonstrate great potential as a high-performance sensing material for application in H2S gas sensors. [ABSTRACT FROM AUTHOR]

Published
2022
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