A. Kumatani, H. Ogawa, T. Endo, J. Lustikova, H. Ida, Y. Takahashi, Y. Miyata, Y. Ikuhara, H. Shiku, Y. Wakayama
Two-dimensional transition metal dichalcogenides (2D TMDs) have shown exceptional electrochemical catalytic activity for the efficient generation of hydrogen through electrochemical water splitting. In the case of molybdenum disulfide (MoS2), a prominent member of 2D TMDs, the electrochemically active sites primarily reside at the edges, while the basal plane, which constitutes the majority of the MoS2 structure, remains relatively inactive. In this study, we aimed to activate the inert sites of the basal plane with some defective structure for hydrogen evolution reaction (HER) by employing an electrochemical-probe in combination with voltage sweeping. The initiation of HER at these previously inactive sites was visualized and confirmed using scanning electrochemical cell microscopy (SECCM). Our findings reveal that the enhanced HER activity originates from surface defects induced by the probing process.
{"title":"Emergence of electrochemical catalytic activity via an electrochemical-probe on defective transition metal dichalcogenide nanosheets","authors":"A. Kumatani, H. Ogawa, T. Endo, J. Lustikova, H. Ida, Y. Takahashi, Y. Miyata, Y. Ikuhara, H. Shiku, Y. Wakayama","doi":"10.1063/5.0175653","DOIUrl":"https://doi.org/10.1063/5.0175653","url":null,"abstract":"Two-dimensional transition metal dichalcogenides (2D TMDs) have shown exceptional electrochemical catalytic activity for the efficient generation of hydrogen through electrochemical water splitting. In the case of molybdenum disulfide (MoS2), a prominent member of 2D TMDs, the electrochemically active sites primarily reside at the edges, while the basal plane, which constitutes the majority of the MoS2 structure, remains relatively inactive. In this study, we aimed to activate the inert sites of the basal plane with some defective structure for hydrogen evolution reaction (HER) by employing an electrochemical-probe in combination with voltage sweeping. The initiation of HER at these previously inactive sites was visualized and confirmed using scanning electrochemical cell microscopy (SECCM). Our findings reveal that the enhanced HER activity originates from surface defects induced by the probing process.","PeriodicalId":505149,"journal":{"name":"APL Energy","volume":"14 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140426656","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We have designed and fabricated TiN/SiO2/TiN–HfO2-based new metamaterial microstructures as an absorber of the visible wavelength, in the range of 400–700 nm, with exceptionally high absorption efficiency (>96%) for solar energy harvesting purposes and generation of heat upon absorption of electromagnetic energy. The finite element method-based COMSOL Multiphysics software simulations were used to optimize the structural parameters of the microstructures and visualize the electric field and electromagnetic power loss distribution in the structure. An optimized 2D unit cell of the structure consists of a 4 μm × 160 nm TiN base on a glass substrate covered with a 70 nm thick SiO2 film. A periodic structure of TiN straps (each 90 nm thick and 2 μm wide) is deposited over the SiO2. The straps are capped with a 40 nm thick layer of high-temperature dielectric HfO2 with a periodicity of 4 µm. This unit is symmetric along the other dimension and is repeated periodically along the horizontal direction. Similar optimized parameters were used for 7, 10, and 100 µm periodic structures to investigate the effect of grating structure pitch on the absorption of light. Although these microstructures were optimized for the visible light spectrum, they show absorption efficiency of >92% when integrated over a broadband wavelength spectrum ranging from 400 to 1200 nm. The experimental data show excellent agreement with the simulated results. We observe less than 5% difference between experimental and simulated absorption efficiencies for the investigated microstructures. Furthermore, we should emphasize that, to the best of our knowledge, this is the first study to experimentally report the light to heat conversion in metamaterials with micron-range size patterned structures.
{"title":"Solar energy harvesting using new broadband metamaterial solar absorbers for generation of heat","authors":"Vivek Khichar, Nader Hozhabri, A. R. Koymen","doi":"10.1063/5.0179924","DOIUrl":"https://doi.org/10.1063/5.0179924","url":null,"abstract":"We have designed and fabricated TiN/SiO2/TiN–HfO2-based new metamaterial microstructures as an absorber of the visible wavelength, in the range of 400–700 nm, with exceptionally high absorption efficiency (>96%) for solar energy harvesting purposes and generation of heat upon absorption of electromagnetic energy. The finite element method-based COMSOL Multiphysics software simulations were used to optimize the structural parameters of the microstructures and visualize the electric field and electromagnetic power loss distribution in the structure. An optimized 2D unit cell of the structure consists of a 4 μm × 160 nm TiN base on a glass substrate covered with a 70 nm thick SiO2 film. A periodic structure of TiN straps (each 90 nm thick and 2 μm wide) is deposited over the SiO2. The straps are capped with a 40 nm thick layer of high-temperature dielectric HfO2 with a periodicity of 4 µm. This unit is symmetric along the other dimension and is repeated periodically along the horizontal direction. Similar optimized parameters were used for 7, 10, and 100 µm periodic structures to investigate the effect of grating structure pitch on the absorption of light. Although these microstructures were optimized for the visible light spectrum, they show absorption efficiency of >92% when integrated over a broadband wavelength spectrum ranging from 400 to 1200 nm. The experimental data show excellent agreement with the simulated results. We observe less than 5% difference between experimental and simulated absorption efficiencies for the investigated microstructures. Furthermore, we should emphasize that, to the best of our knowledge, this is the first study to experimentally report the light to heat conversion in metamaterials with micron-range size patterned structures.","PeriodicalId":505149,"journal":{"name":"APL Energy","volume":"425 12","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140472959","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Supercapacitors, as high-performance energy storage devices, have garnered extensive research interest. Furthermore, capacitive deionization technology based on a supercapacitor has emerged as a crucial solution to tackling issues of freshwater scarcity and seawater pollution. However, their power density and cycling lifespan remain constrained by electrode materials. In recent years, 3D network graphene materials have gained prominence as an ideal choice due to their unique porous structure, high specific surface area, and excellent conductivity. This review summarizes the preparation methods of 3D network graphene materials, including techniques like chemical vapor deposition, graphene oxide reduction, and foaming methods. It also discusses their applications and the ongoing research advancements in supercapacitor energy storage and capacitive deionization. Ultimately, this review offers researchers an understanding and outlook on the application of 3D network graphene materials in supercapacitor energy storage and capacitive deionization.
{"title":"Three-dimensional network of graphene for electrochemical capacitors and capacitive deionization","authors":"Hongda Zhu, Dingfei Deng, Chiwei Xu, Xuebin Wang, Xiangfen Jiang","doi":"10.1063/5.0177677","DOIUrl":"https://doi.org/10.1063/5.0177677","url":null,"abstract":"Supercapacitors, as high-performance energy storage devices, have garnered extensive research interest. Furthermore, capacitive deionization technology based on a supercapacitor has emerged as a crucial solution to tackling issues of freshwater scarcity and seawater pollution. However, their power density and cycling lifespan remain constrained by electrode materials. In recent years, 3D network graphene materials have gained prominence as an ideal choice due to their unique porous structure, high specific surface area, and excellent conductivity. This review summarizes the preparation methods of 3D network graphene materials, including techniques like chemical vapor deposition, graphene oxide reduction, and foaming methods. It also discusses their applications and the ongoing research advancements in supercapacitor energy storage and capacitive deionization. Ultimately, this review offers researchers an understanding and outlook on the application of 3D network graphene materials in supercapacitor energy storage and capacitive deionization.","PeriodicalId":505149,"journal":{"name":"APL Energy","volume":"194 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140475248","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kh M Asif Raihan, S. Sahoo, T. Nagaraja, Shusil Sigdel, Brice Lacroix, Christopher M. Sorensen, Suprem R. Das
The ever-growing demand for portable, bendable, twistable, and wearable microelectronics operating in a wide temperature range has stimulated an immense interest in the development of solid-state flexible energy storage devices using scalable fabrication technology. Herein, we developed additively manufactured graphene aerosol gel-based all-solid-state micro-supercapacitors (MSCs) via inkjet printing with functioning temperature in the range from −15 to +70 °C and exhibiting a super-stable and reliable electrochemical performance using interdigitated finger electrodes and PVA/H3PO4 solid-state electrolyte. The graphene aerosol gel was obtained using a scalable single step synthesis method from a gas phase precursor using a detonation process, producing a nanoscale shell type structure. The fabricated graphene aerosol gel-based solid-state MSC achieved a volumetric capacitance of 376.63 mF cm−3 (areal capacitance of 76.23 μF cm−2) at a constant current of 0.25 μA and demonstrated exceptional cyclic stability (∼99.6% of capacitance retention) over 10 000 cycles. To exploit the mechanical strength of the as-fabricated graphene aerosol gel-based solid-state MSC, its supercapacitive performance was scrutinized under various bending and twisting angles and the results showed excellent mechanical flexibility. Furthermore, to study the electrochemical performance of the as-fabricated graphene aerosol gel solid-state MSC in stringent surroundings, a broad temperature dependent supercapacitive analysis was performed as stated above. The electrochemical results of the as-fabricated graphene aerosol gel based all-solid-state MSC exhibit a highly potential route to develop scalable and authentic future miniaturized energy storage devices for IoT based smart electronic appliances.
{"title":"Transforming scalable synthesis of graphene aerosol gel material toward highly flexible and wide-temperature tolerant printed micro-supercapacitors","authors":"Kh M Asif Raihan, S. Sahoo, T. Nagaraja, Shusil Sigdel, Brice Lacroix, Christopher M. Sorensen, Suprem R. Das","doi":"10.1063/5.0186302","DOIUrl":"https://doi.org/10.1063/5.0186302","url":null,"abstract":"The ever-growing demand for portable, bendable, twistable, and wearable microelectronics operating in a wide temperature range has stimulated an immense interest in the development of solid-state flexible energy storage devices using scalable fabrication technology. Herein, we developed additively manufactured graphene aerosol gel-based all-solid-state micro-supercapacitors (MSCs) via inkjet printing with functioning temperature in the range from −15 to +70 °C and exhibiting a super-stable and reliable electrochemical performance using interdigitated finger electrodes and PVA/H3PO4 solid-state electrolyte. The graphene aerosol gel was obtained using a scalable single step synthesis method from a gas phase precursor using a detonation process, producing a nanoscale shell type structure. The fabricated graphene aerosol gel-based solid-state MSC achieved a volumetric capacitance of 376.63 mF cm−3 (areal capacitance of 76.23 μF cm−2) at a constant current of 0.25 μA and demonstrated exceptional cyclic stability (∼99.6% of capacitance retention) over 10 000 cycles. To exploit the mechanical strength of the as-fabricated graphene aerosol gel-based solid-state MSC, its supercapacitive performance was scrutinized under various bending and twisting angles and the results showed excellent mechanical flexibility. Furthermore, to study the electrochemical performance of the as-fabricated graphene aerosol gel solid-state MSC in stringent surroundings, a broad temperature dependent supercapacitive analysis was performed as stated above. The electrochemical results of the as-fabricated graphene aerosol gel based all-solid-state MSC exhibit a highly potential route to develop scalable and authentic future miniaturized energy storage devices for IoT based smart electronic appliances.","PeriodicalId":505149,"journal":{"name":"APL Energy","volume":"1 7","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139598560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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