Vinicius Alevato, Daniel Streater, Cole Premtaj, Jier Huang, Stephanie L. Brock
{"title":"光催化析氢用CdS量子点气凝胶","authors":"Vinicius Alevato, Daniel Streater, Cole Premtaj, Jier Huang, Stephanie L. Brock","doi":"10.1007/s12274-024-7107-2","DOIUrl":null,"url":null,"abstract":"<div><p>CdS quantum dots (QDs) have been extensively studied as photocatalysts and sensitizers for visible-light-driven water reduction. However, their efficiencies are limited by the need to accumulate sufficient redox equivalents to produce H<sub>2</sub> and consequent photocorrosion associated with slow hole-transfer rates. To address these limitations, we report the formation of CdS QD assemblies (aerogels, AGs) capable of facilitating energy/charge transport between individual QDs, and evaluate their performance as photocatalysts for hydrogen evolution as a function of structure, wurtzite (<i>w</i>-) vs. zincblende (<i>zb</i>-), and different annealing temperatures. The formation of AGs from QDs resulted in increased rates of H<sub>2</sub> production under visible light illumination: from 1458 (QD) to 6650 (AG) µmol<sub>H2</sub>·h<sup>−1</sup>·g<sup>−1</sup> on zbCdS and from 1221 (QD) to 3325 (AG) µmol<sub>H2</sub>·h<sup>−1</sup>·g<sup>−1</sup> on wCdS. This is attributed to exciton delocalization between adjacent QDs facilitating charge/energy transport. Thermal processing of CdS AGs up to 250 °C improved their activity, increasing the degree of exciton delocalization, while annealing them to 300 °C caused sintering of the primary QD particles within the AGs and a decrease in activity associated with loss in surface area. The best photocatalyst, <i>zb</i>CdS AG annealed at 250°C, had an average H<sub>2</sub> production rate of 13,604 ± 2017 µmol<sub>H2</sub>·h<sup>−1</sup>·g<sup>−1</sup>, an apparent quantum yield of 2.8% at 425 ± 12.5 nm, and was stable for 2 h before beginning to deactivate due to photocorrosion. This study confirms the potential of CdS AGs as matrixes for the design of more active and stable composite photocatalysts for water splitting.\n</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>","PeriodicalId":713,"journal":{"name":"Nano Research","volume":"17 :","pages":"10292 - 10301"},"PeriodicalIF":9.0000,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"CdS quantum dot aerogels for photocatalytic hydrogen evolution\",\"authors\":\"Vinicius Alevato, Daniel Streater, Cole Premtaj, Jier Huang, Stephanie L. Brock\",\"doi\":\"10.1007/s12274-024-7107-2\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><p>CdS quantum dots (QDs) have been extensively studied as photocatalysts and sensitizers for visible-light-driven water reduction. However, their efficiencies are limited by the need to accumulate sufficient redox equivalents to produce H<sub>2</sub> and consequent photocorrosion associated with slow hole-transfer rates. To address these limitations, we report the formation of CdS QD assemblies (aerogels, AGs) capable of facilitating energy/charge transport between individual QDs, and evaluate their performance as photocatalysts for hydrogen evolution as a function of structure, wurtzite (<i>w</i>-) vs. zincblende (<i>zb</i>-), and different annealing temperatures. The formation of AGs from QDs resulted in increased rates of H<sub>2</sub> production under visible light illumination: from 1458 (QD) to 6650 (AG) µmol<sub>H2</sub>·h<sup>−1</sup>·g<sup>−1</sup> on zbCdS and from 1221 (QD) to 3325 (AG) µmol<sub>H2</sub>·h<sup>−1</sup>·g<sup>−1</sup> on wCdS. This is attributed to exciton delocalization between adjacent QDs facilitating charge/energy transport. Thermal processing of CdS AGs up to 250 °C improved their activity, increasing the degree of exciton delocalization, while annealing them to 300 °C caused sintering of the primary QD particles within the AGs and a decrease in activity associated with loss in surface area. The best photocatalyst, <i>zb</i>CdS AG annealed at 250°C, had an average H<sub>2</sub> production rate of 13,604 ± 2017 µmol<sub>H2</sub>·h<sup>−1</sup>·g<sup>−1</sup>, an apparent quantum yield of 2.8% at 425 ± 12.5 nm, and was stable for 2 h before beginning to deactivate due to photocorrosion. This study confirms the potential of CdS AGs as matrixes for the design of more active and stable composite photocatalysts for water splitting.\\n</p><div><figure><div><div><picture><source><img></source></picture></div></div></figure></div></div>\",\"PeriodicalId\":713,\"journal\":{\"name\":\"Nano Research\",\"volume\":\"17 :\",\"pages\":\"10292 - 10301\"},\"PeriodicalIF\":9.0000,\"publicationDate\":\"2024-11-23\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Nano Research\",\"FirstCategoryId\":\"88\",\"ListUrlMain\":\"https://link.springer.com/article/10.1007/s12274-024-7107-2\",\"RegionNum\":2,\"RegionCategory\":\"材料科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q1\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Nano Research","FirstCategoryId":"88","ListUrlMain":"https://link.springer.com/article/10.1007/s12274-024-7107-2","RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
CdS quantum dot aerogels for photocatalytic hydrogen evolution
CdS quantum dots (QDs) have been extensively studied as photocatalysts and sensitizers for visible-light-driven water reduction. However, their efficiencies are limited by the need to accumulate sufficient redox equivalents to produce H2 and consequent photocorrosion associated with slow hole-transfer rates. To address these limitations, we report the formation of CdS QD assemblies (aerogels, AGs) capable of facilitating energy/charge transport between individual QDs, and evaluate their performance as photocatalysts for hydrogen evolution as a function of structure, wurtzite (w-) vs. zincblende (zb-), and different annealing temperatures. The formation of AGs from QDs resulted in increased rates of H2 production under visible light illumination: from 1458 (QD) to 6650 (AG) µmolH2·h−1·g−1 on zbCdS and from 1221 (QD) to 3325 (AG) µmolH2·h−1·g−1 on wCdS. This is attributed to exciton delocalization between adjacent QDs facilitating charge/energy transport. Thermal processing of CdS AGs up to 250 °C improved their activity, increasing the degree of exciton delocalization, while annealing them to 300 °C caused sintering of the primary QD particles within the AGs and a decrease in activity associated with loss in surface area. The best photocatalyst, zbCdS AG annealed at 250°C, had an average H2 production rate of 13,604 ± 2017 µmolH2·h−1·g−1, an apparent quantum yield of 2.8% at 425 ± 12.5 nm, and was stable for 2 h before beginning to deactivate due to photocorrosion. This study confirms the potential of CdS AGs as matrixes for the design of more active and stable composite photocatalysts for water splitting.
期刊介绍:
Nano Research is a peer-reviewed, international and interdisciplinary research journal that focuses on all aspects of nanoscience and nanotechnology. It solicits submissions in various topical areas, from basic aspects of nanoscale materials to practical applications. The journal publishes articles on synthesis, characterization, and manipulation of nanomaterials; nanoscale physics, electrical transport, and quantum physics; scanning probe microscopy and spectroscopy; nanofluidics; nanosensors; nanoelectronics and molecular electronics; nano-optics, nano-optoelectronics, and nano-photonics; nanomagnetics; nanobiotechnology and nanomedicine; and nanoscale modeling and simulations. Nano Research offers readers a combination of authoritative and comprehensive Reviews, original cutting-edge research in Communication and Full Paper formats. The journal also prioritizes rapid review to ensure prompt publication.